WO2016124073A1 - Method for preparing micrometer and nanometer composite metallic spherical powder having core-shell structure - Google Patents

Abstract

A method for preparing micrometer and nanometer composite metallic spherical powder having a core-shell structure, comprising the following steps: (1) preparing a composite metallic powder precursor; (2) preparing the powder uniformly mixed with the composite metallic powder precursor and carbon material powder or ceramic material powder; (3) melting one of the metals in the composite metallic precursor via a heat treatment at high temperature, and forming a composite metallic ball having the core-shell structure after solidification; (4) removing the carbon material powder or the ceramic material powder to obtain the micrometer and the nanometer composite metallic spherical powder having the core-shell structure.

Description

核壳结构微米和纳米复合金属球形粉末的制造方法Core-shell structure micron and nano composite metal spherical powder manufacturing method 技术领域Technical field

本发明涉及适用于在粉末冶金、导电浆料、硬质合金、磁性材料、传感、光学、催化等领域的广泛应用。The invention relates to a wide range of applications suitable for use in the fields of powder metallurgy, conductive paste, cemented carbide, magnetic materials, sensing, optics, catalysis, and the like.

背景技术Background technique

核壳结构金属粒子是由两种或两种以上不同性质的金属组成的复合粒子，一般由中心的核体以及包覆在外部的壳层组成。与单一的金属粒子相比，核壳结构金属粒子具有独特的结构特性，它整合了内外两种材料的性质，并互相补充各自的不足，是近几年形貌决定性质的一个重要研究方向。由于核壳结构复合粒子的结构和组成能够进行设计和剪裁,因而具有许多不同于单组分粒子的独特的光、电、磁、力、催化等物理和化学性质,是构筑新型功能材料的重要组元。核壳结构复合粒子可通过化学或物理方法来制备，其构造策略有两种:一种是先成核,后包覆壳；另一种是一次性形成核壳结构。与以上合成策略相对应，化学法中的有两种常用的核壳结构的合成方法：连续还原法(先将一种金属盐还原形成“晶种”(也就是核)，再利用一个类似于“晶种生长”的过程，使另一种金属的原子沉积附着在已形成的金属晶种表面，形成核壳结构)和共还原法(体系中同时存在两种金属盐前驱体，还原过程中氧化还原电势更高的金属物种首先沉积成核，而电势低的金属后还原，在其表面沉积成壳,从而形成核壳结构)，这两种方法都可以合成核壳结构的双金属纳米粒子。化学法制备金属核壳结构一般是在液体中进行，液相化学还原是一个复杂的反应体系,涉及众多因素(温度、pH值、溶剂、金属前驱体、还原剂、络合剂/保护剂的种类及杂质离子等)，任何因素的变化都对产物造成一定程度影响,如粒子的平均尺寸、形貌、分散度等，规模化生产控制难度大；另外，金属本身的固有属性会影响金属核壳结构复合粒子形成(尤其是微结构)，比如，两种金属电极电势的相对高低,相图中两种金属的相对关系等。物理法中与以上合成策略相对应的有先成核，后包覆壳(如：高低温两步热处理固态反应法，Highly monodisperse core–shell particles created by solid-state reactions；Nature Materials,10,710(2011))和一次性形成核壳结构(如：雾化法，Farmation of Immiscible Alloy poders with egg-type microstructure,Science 297,990(2002))。高低温两步热处理固态反应法是通过高温热处理形成核，低温热处理时在高温析出的核上生长壳。这种核壳结构粒子分布在金属基体中，这种方法只适用于一些特定的金属材料体系，如AlLiSc合金。雾化法是通过将合金熔化，雾化成微米液滴，在冷却过程中，合金液体会由单一液相转变成不互熔的两液相而分离，由于表面能的差异，获得核壳结构。专利申请号为201210395540.5的专利提供了一种通过雾化法制备银基包裹铜镍基合金的核壳结构复合粒子粉体的方法，其步骤是将铜、镍、银各金属放入真空感应炉内的熔炼装置熔化；将熔化的合金液体倾倒于受液斗，在液体流入雾化室的瞬间，喷射惰性气体，冷却后可得核壳结构的铜镍银复合球形粉体。专利申请号为200810070976.0的专利提供了一种通过雾化法制备铜基合金包裹不锈钢的核壳结构复合粒子粉体的方法，其步骤是将铜、铁铬各金属放入真空感应炉内的熔炼装置熔化；将熔化的合金液体倾倒于受液斗，在液体流入雾化室的瞬间，喷射惰性气体，冷却后可得核壳结构的铜/不锈钢复合球形粉体。但上述专利制备的核壳结构复合金属也存在一些问题：1)对复合金属材料系列有特定的限制，需要复合金属在液相时高温相溶，冷却过程中存在相分离为两不相溶的液相；2)制备金属核壳结构球形粉末的工艺，比如温度和冷却速度都难以控制，金属颗粒的冷却历史不一致；3)颗粒尺寸分布宽，难制备颗粒尺寸小于20微米以下的核壳结构复合金属粉末。专利申请号CN201410462791.X公布了一种微米和纳米金属球形粉末的制造方法，提出通过金属液滴/碳材料或陶瓷材料界面(即：液/固界面)的方法制备微米、纳米金属球。其原理是用碳材料粉末或用陶瓷材料粉末充分隔开金属颗粒，提供蓬松的分散环境，利用金属液滴在碳材料或在陶瓷材料固体界面不润湿或低润湿、不扩散或少扩散的性质，在液固界面液滴的界面张力和液气界面液滴表面张力同时作用下形成球形金属液滴，冷却后获得微米和纳米金属球。这种方法让我们能有效控制液滴合金的保温时间和冷却速度，通过设计合金成分和热处理工艺，能制备高质量的核壳结构金属复合球形粉末。Core-shell structured metal particles are composite particles composed of two or more metals of different nature, generally consisting of a central core body and a shell layer coated on the outside. Compared with a single metal particle, the core-shell structure metal particle has unique structural characteristics. It integrates the properties of the inner and outer materials and complements each other's deficiencies. It is an important research direction of the shape determining properties in recent years. Since the structure and composition of core-shell composite particles can be designed and tailored, it has many unique physical and chemical properties such as light, electricity, magnetism, force, and catalysis, which are different from single-component particles, and is important for constructing new functional materials. Component. Core-shell composite particles can be prepared by chemical or physical methods. There are two structural strategies: one is nucleation first, then the shell is coated; the other is a one-time formation of core-shell structure. Corresponding to the above synthetic strategy, there are two common methods for the synthesis of core-shell structures in the chemical process: continuous reduction (reducing a metal salt to form a "seed" (ie, a core), and then using a similar The process of "seed growth" causes the deposition of another metal atom to adhere to the surface of the formed metal seed to form a core-shell structure) and the co-reduction method (the two metal salt precursors exist simultaneously in the system, during the reduction process) The metal species with higher redox potential are first deposited as nucleation, and the metal with lower potential is reduced and deposited on the surface to form a core-shell structure. Both methods can synthesize bimetallic nanoparticles with core-shell structure. . Chemical preparation of metal core-shell structures is generally carried out in liquids. Liquid phase chemical reduction is a complex reaction system involving many factors (temperature, pH, solvent, metal precursor, reducing agent, complexing agent/protective agent). Types and impurity ions, etc., any change in factors affect the product to a certain extent, such as the average size, morphology, dispersion of the particles, etc., large-scale production control is difficult; in addition, the inherent properties of the metal itself will affect the metal core Shell structure composite particle formation (especially microstructure), for example, the relative height of the two metal electrode potentials, the relative relationship of the two metals in the phase diagram, and so on. In the physical method, there are pre-nucleation and post-coating shells corresponding to the above synthetic strategy (eg, high-low temperature disperse core-shell particles created by solid-state reactions; Nature Materials, 10, 710 (2011) )) and one-time formation of core-shell structure (eg, atomization method, Farmation of Immiscible Alloy poders with egg-type microstructure, Science) 297,990 (2002)). The high-low temperature two-step heat treatment solid state reaction method is to form a core by high-temperature heat treatment, and a shell is grown on the core precipitated at a high temperature during low-temperature heat treatment. This core-shell structure particle is distributed in the metal matrix. This method is only applicable to some specific metal material systems, such as AlLiSc alloy. The atomization method is obtained by melting the alloy and atomizing it into micron droplets. During the cooling process, the alloy liquid is separated from a single liquid phase into two liquid phases which are not mutually melted, and the core-shell structure is obtained due to the difference in surface energy. Patent No. 201210395540.5 provides a method for preparing a core-shell composite particle powder of a silver-based copper-nickel-based alloy by an atomization method, the step of which is to place copper, nickel, and silver metals into a vacuum induction furnace. The melting device in the inside melts; the molten alloy liquid is poured into the liquid receiving hopper, and the inert gas is sprayed at the moment when the liquid flows into the atomizing chamber, and after cooling, a copper-nickel-silver composite spherical powder having a core-shell structure can be obtained. Patent No. 200810070976.0 provides a method for preparing a copper-based alloy-coated stainless steel core-shell composite particle powder by an atomization method, the step of which is to melt copper, iron and chromium into a vacuum induction furnace. The device is melted; the molten alloy liquid is poured into the liquid receiving hopper, and the inert gas is sprayed at the moment when the liquid flows into the atomizing chamber, and after cooling, a copper/stainless steel composite spherical powder having a core-shell structure can be obtained. However, there are some problems in the core-shell composite metal prepared by the above patents: 1) There are specific restrictions on the series of composite metal materials, and it is required that the composite metal is dissolved at a high temperature in the liquid phase, and the phase separation in the cooling process is two incompatible. Liquid phase; 2) Process for preparing spherical powder of metal core-shell structure, such as temperature and cooling rate are difficult to control, cooling history of metal particles is inconsistent; 3) particle size distribution is wide, and it is difficult to prepare core-shell structure with particle size less than 20 microns Composite metal powder. Patent application No. CN201410462791.X discloses a method for producing a micron and nano metal spherical powder, and proposes to prepare micron and nano metal spheres by a method of metal droplet/carbon material or ceramic material interface (ie, liquid/solid interface). The principle is to use a carbon material powder or a ceramic material powder to sufficiently separate the metal particles to provide a fluffy dispersion environment, using metal droplets to be non-wetting or low-wetting, non-diffusion or less diffusion at the carbon material or at the solid interface of the ceramic material. The properties of the droplets at the liquid-solid interface and the surface tension of the droplets at the liquid-gas interface simultaneously form spherical metal droplets, and after cooling, micro- and nano-metal spheres are obtained. This method allows us to effectively control the holding time and cooling rate of the droplet alloy. By designing the alloy composition and the heat treatment process, a high-quality core-shell metal composite spherical powder can be prepared.

发明内容Summary of the invention

本发明的目的在于，提供一种核壳结构微米和纳米复合金属球形粉末的制造方法，通过将复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末混合，使复合金属粉末前驱物被碳材料粉末或被陶瓷材料粉末隔开。在达到或高于复合金属前驱物中一种 或一种以上金属的熔点的某一温度保温，形成金属液滴/碳材料或陶瓷材料界面(即：液/固界面)，利用金属液滴在碳材料或在陶瓷材料固体界面不润湿或低润湿、不扩散或少扩散的性质，在固液界面液滴的界面张力和液体的表面张力同时作用下，形成球形金属液滴；同时，利用复合金属前驱物熔化后液相不相溶或利用复合金属前驱物中部分金属熔化，熔化的金属与未熔化的固态物质不固溶、低固溶的特点，在表面能和两相的界面能同时作用下实现分层包覆，在冷却过程中获得核壳结构微米和纳米复合金属球。It is an object of the present invention to provide a method for producing a core-shell micron and nano composite metal spherical powder, which is obtained by mixing a composite metal powder precursor with a carbon material powder or a ceramic material powder, so that the composite metal powder precursor is made of a carbon material. The powder is either separated by a ceramic material powder. At or above a composite metal precursor Or a certain temperature of the melting point of more than one metal to form a metal droplet / carbon material or ceramic material interface (ie: liquid / solid interface), using metal droplets in the carbon material or at the solid interface of the ceramic material does not wet or Low wetting, non-diffusion or low diffusion property, the spherical metal droplets are formed under the action of the interfacial tension of the droplets at the solid-liquid interface and the surface tension of the liquid; at the same time, the liquid phase is incompatible after being melted by the composite metal precursor. Or by using a part of the metal in the composite metal precursor to melt, the molten metal and the unmelted solid matter are not solid solution and low solid solution, and the layered coating is realized under the simultaneous action of the surface energy and the interface energy of the two phases. The core-shell micro- and nano-composite metal spheres are obtained during the process.

本发明的技术方案是：核壳结构微米和纳米复合金属球形粉末的制造方法，包括如下步骤：(1)准备复合金属(此处金属所指为单质金属、合金或金属间化合物)粉末前驱物；(2)准备的复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末；(3)高温热处理使复合金属前驱物中一种以上的金属熔融，凝固后形成核壳结构复合金属球；高温热处理温度至少达到所述复合金属前驱物中一种金属的熔融温度，尤其是温度在该金属熔点以上40℃到100℃的范围内；(4)除掉碳材料粉末或陶瓷材料粉末获得核壳结构微米和纳米复合金属球形粉末。The technical scheme of the present invention is: a method for manufacturing a core-shell micro- and nano-composite metal spherical powder, comprising the following steps: (1) preparing a powder precursor of a composite metal (here, the metal is referred to as an elemental metal, an alloy or an intermetallic compound) (2) prepared composite metal powder precursor and carbon material powder or uniformly mixed powder with ceramic material powder; (3) high temperature heat treatment causes more than one metal in the composite metal precursor to melt, solidified to form core-shell structure composite a metal ball; a high temperature heat treatment temperature of at least a melting temperature of a metal in the composite metal precursor, especially a temperature in the range of 40 ° C to 100 ° C above the melting point of the metal; (4) removal of carbon material powder or ceramic material The powder obtained a spherical shell-shell micron and nanocomposite metal spherical powder.

具有核壳结构球形粉末的复合金属包括：1)液态时某一温度区间存在两种或两种以上不相溶液相的金属，包括：铁(或铁基合金)/铜(或铜基合金)、铁(或铁基合金)/银(或银基合金)、钴(或钴基合金)/银(或银基合金)、镍(或镍基合金)/银(或银基合金)、钨(或钨基合金)/铜(或铜基合金)、钨(或钨基合金)/银(或银基合金)、碳化钨/铜(或铜基合金)、碳化钨/银(或银基合金)、铁(或铁基合金)/铋(或铋基合金)、钴(或钴基合金)/铋(或铋基合金)等；2)两种或两种以上液态相溶，固态不固溶或低固溶，即在某一温度区间，存在液、固相共存的金属，包括：银(或银基合金)/铜(或铜基合金)、铝(或铝基合金)/硅(或硅基合金)、锡(或锡基合金)/铋(或铋基合金)、铜(或铜基合金)/铋(或铋基合金)、钴(或钴基合金)/铜(或铜基合金)、金(或金基合金)/铜(或铜基合金)等。A composite metal having a core-shell structured spherical powder includes: 1) a metal having two or more incompatible phase phases in a liquid temperature range, including: iron (or iron-based alloy) / copper (or copper-based alloy) , iron (or iron-based alloy) / silver (or silver-based alloy), cobalt (or cobalt-based alloy) / silver (or silver-based alloy), nickel (or nickel-based alloy) / silver (or silver-based alloy), tungsten (or tungsten-based alloy) / copper (or copper-based alloy), tungsten (or tungsten-based alloy) / silver (or silver-based alloy), tungsten carbide / copper (or copper-based alloy), tungsten carbide / silver (or silver base) Alloy), iron (or iron-based alloy) / niobium (or niobium-based alloy), cobalt (or cobalt-based alloy) / niobium (or niobium-based alloy), etc.; 2) two or more liquids are compatible, solid state is not Solid solution or low solid solution, that is, in a certain temperature range, there are metals in which liquid and solid phases coexist, including: silver (or silver-based alloy) / copper (or copper-based alloy), aluminum (or aluminum-based alloy) / silicon (or silicon-based alloy), tin (or tin-based alloy) / niobium (or niobium-based alloy), copper (or copper-based alloy) / niobium (or niobium-based alloy), cobalt (or cobalt-based alloy) / copper (or Copper-based alloys, gold (or gold-based alloys) / copper (or copper-based alloys), and the like.

准备所述复合金属粉末前驱物原料包括：1)将两种或两种以上的金属粉末通过混合获得均匀的复合粉末；2)通过熔炼获得复合金属，破碎成复合金属粉末，3)快淬成条带后破碎成复合金属粉末；4)通过机械合金化获得的复合合金粉末；5)通过混合不同的金属氧化物或金属盐得到均匀的复合氧化物或金属盐，还原后获得均匀的 复合金属粉末；6)通过电化学反应或其他方法包覆的复合金属粉末；7)通过其他方法获得的复合金属粉末。The preparation of the composite metal powder precursor material comprises: 1) mixing two or more metal powders to obtain a uniform composite powder; 2) obtaining a composite metal by smelting, breaking into a composite metal powder, and 3) rapidly quenching After the strip is broken into composite metal powder; 4) composite alloy powder obtained by mechanical alloying; 5) by mixing different metal oxides or metal salts to obtain a uniform composite oxide or metal salt, and obtaining uniformity after reduction Composite metal powder; 6) composite metal powder coated by electrochemical reaction or other methods; 7) composite metal powder obtained by other methods.

所述复合金属粉末前驱物尺寸小于10mm,优选尺寸范围在50nm～1mm。The composite metal powder precursor has a size of less than 10 mm, preferably a size ranging from 50 nm to 1 mm.

碳材料粉末为石墨、石墨烯、金刚石、碳粉或煤粉以及它们二种或二种以上的混合物；陶瓷材料粉末为碳化物陶瓷、硼化物陶瓷、氧化物陶瓷或氮化物陶瓷以及它们二种或二种以上的混合物。The carbon material powder is graphite, graphene, diamond, carbon powder or coal powder and a mixture of two or more kinds thereof; the ceramic material powder is a carbide ceramic, a boride ceramic, an oxide ceramic or a nitride ceramic, and both of them Or a mixture of two or more.

准备复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末的方法为下述之一，i)采取机械方法均匀混合；ii)在液体(如水、乙醇等)中搅拌均匀混合；iii)通过分散剂辅助分散后，与碳材料粉末或陶瓷材料粉末混合，混合后干燥得到用碳材料或用陶瓷材料包覆的复合金属粉末前驱物的均匀的混合粉末。The method for preparing the composite metal powder precursor and the carbon material powder or the ceramic powder uniformly mixed powder is one of the following, i) uniformly mixing by mechanical means; ii) stirring uniformly in a liquid (such as water, ethanol, etc.); Iii) After being dispersed by the dispersant, it is mixed with the carbon material powder or the ceramic material powder, mixed and dried to obtain a uniform mixed powder of the composite metal powder precursor coated with the carbon material or the ceramic material.

用以上方式将两种或以上的金属氧化物或金属盐前驱物与碳材料粉末或与陶瓷材料粉末混合，在还原气氛中(如氢气、氨气、一氧化碳、或她们的混合气体等)进行热处理，得到复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末。Two or more metal oxide or metal salt precursors are mixed with a carbon material powder or a ceramic material powder in the above manner, and heat-treated in a reducing atmosphere (such as hydrogen, ammonia, carbon monoxide, or a mixed gas thereof) A uniform mixed powder of the composite metal powder precursor with the carbon material powder or with the ceramic material powder is obtained.

将所述复合金属粉末前驱物用碳材料粉末或陶瓷材料粉末隔开；复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的质量比应满足所称量的复合金属粉末前驱物的总表面积小于所配比的碳材料粉末或陶瓷材料粉末的总表面积；所述碳材料粉末或陶瓷材料粉末可以是任意大小的尺寸，10纳米-100微米粒径的范围更好；碳材料粉末或陶瓷材料粉末的形貌可以是片状、球状、线状、管状或其他形状。Separating the composite metal powder precursor with carbon material powder or ceramic material powder; the mass ratio of the composite metal powder precursor to the carbon material powder or the ceramic material powder should satisfy the total surface area of the weighed composite metal powder precursor Less than the total surface area of the proportioned carbon material powder or ceramic material powder; the carbon material powder or ceramic material powder may be any size, and the range of 10 nm to 100 μm particle diameter is better; carbon material powder or ceramic material The morphology of the powder can be in the form of flakes, spheres, wires, tubes or other shapes.

将混合均匀的复合金属粉末前驱物/碳材料或陶瓷材料混合粉末在真空或气氛(包括氢气、氮气、氩气和氨气等)中热处理，温度：至少达到所述复合金属前驱物中一种金属的熔融温度，优选的温度为高于该种金属熔点40～100℃；保温时间：保证金属完全熔化，优选时间为4～10分钟，短时保温克服金属液滴与碳材料或陶瓷材料之间的相互扩散，保证金属液滴在碳材料或陶瓷材料界面的不润湿性或低润湿性；冷却方式：1)快冷，让复合金属颗粒保持液态金属球的形状，同时，克服合金材料成分宏观偏析和减少高温下碳材料或陶瓷材料向金属颗粒的扩散；2)快冷结合缓慢冷却，快冷到熔点以下温度后，再缓慢冷却，获到结晶度好的核壳结构微米和纳米复合金属球。Mixing the uniformly mixed composite metal powder precursor/carbon material or ceramic material mixed powder in a vacuum or atmosphere (including hydrogen, nitrogen, argon, ammonia, etc.) at a temperature of at least one of the composite metal precursors The melting temperature of the metal, preferably 40 to 100 ° C above the melting point of the metal; holding time: to ensure complete melting of the metal, preferably 4 to 10 minutes, short-term insulation against metal droplets and carbon or ceramic materials Interdiffusion to ensure non-wetting or low wetting of metal droplets at the interface of carbon or ceramic materials; cooling method: 1) rapid cooling, allowing composite metal particles to maintain the shape of liquid metal spheres, while overcoming alloys Macroscopic segregation of material composition and reduction of diffusion of carbon material or ceramic material to metal particles at high temperature; 2) rapid cooling combined with slow cooling, rapid cooling to a temperature below the melting point, and then slowly cooling to obtain a core-shell structure with a good crystallinity Nano composite metal ball.

将高温热处理处理的复合金属/碳材料或陶瓷材料混合粉末中的碳材料粉末或陶 瓷材料粉末分离，获得核壳结构微米和纳米复合金属球形粉末；分离方法包括：1)在液体(如：水或有机溶剂等)中浸泡后，利用复合金属与碳材料或与陶瓷材料大的密度差，超声清洗，除掉碳材料粉末或陶瓷材料粉末，获得核壳结构复合金属球形粉末；2)在液体中浸泡后，采用离心、过滤或外加磁场的方法获得核壳结构复合金属球形粉末；3)利用核壳结构复合金属颗粒与碳材料或与陶瓷材料的形状、大小不同，使用合适的筛子将二者分离。Carbon material powder or ceramic in a composite metal/carbon material or ceramic material mixed powder treated by high temperature heat treatment Porcelain material powder separation, obtaining core-shell micro- and nano-composite metal spherical powder; separation methods include: 1) after immersion in liquid (such as water or organic solvent, etc.), using composite metal and carbon material or ceramic material Density difference, ultrasonic cleaning, removal of carbon material powder or ceramic material powder, obtaining core-shell composite metal spherical powder; 2) after immersion in liquid, using centrifugal, filtration or external magnetic field method to obtain core-shell composite metal spherical powder 3) Using the core-shell structure The composite metal particles are different from the carbon material or the shape and size of the ceramic material, and the two are separated by a suitable sieve.

所述核壳结构复合金属球形粉末的直径小于10mm。优选的金属球形粉末的直径在50nm～1mm的范围。The core-shell composite metal spherical powder has a diameter of less than 10 mm. Preferred metal spherical powders have a diameter in the range of 50 nm to 1 mm.

所制备的核壳结构的微米和纳米复合金属球形粉末颗粒包括内核和外壳。1)对于高温热处理时为不相溶的液相的复合金属：内核是热处理温度时液态表面能最大的金属，外壳是热处理温度时液态表面能最小的金属；2)对于高温热处理时为液、固相共存的复合金属：内核是热处理温度时为固相的金属，外壳是热处理温度时液相中表面能最小的金属。The prepared core-shell structured micron and nanocomposite metal spherical powder particles include a core and an outer shell. 1) For the composite metal which is incompatible in the high temperature heat treatment: the core is the metal with the largest liquid surface energy at the heat treatment temperature, the outer shell is the metal with the smallest liquid surface energy at the heat treatment temperature; 2) the liquid for the high temperature heat treatment, Solid-phase coexisting composite metal: The inner core is a solid phase metal at the heat treatment temperature, and the outer shell is the metal having the smallest surface energy in the liquid phase at the heat treatment temperature.

本发明的有益效果：将复合金属粉末前驱物用碳材料粉末或用陶瓷材料粉末隔开，利用金属液滴在碳材料或在陶瓷材料固体界面不润湿或低润湿、不扩散或少扩散的性质，在液固界面液滴的界面张力和液气界面液滴表面张力同时作用下形成球形金属液滴，同时，利用复合金属熔化后液相不相溶，或利用复合金属中部分金属熔化，液固相共存，液相和固相之间不互溶或低互溶的特点，在表面能和液固两相的界面能共同作用下实现分层包覆，冷却后获得核壳结构的微米和纳米复合金属球。根据本发明，制备核壳结构复合金属球的原理清晰，制造核壳结构复合金属球形粉末的工艺方法简单，制造成本低，生产效率高，是一种简单易行、环境友好、可规模化生产核壳结构微米和纳米复合金属球形粉末的制造方法。制造的核壳结构复合金属球直径小于10mm，优选球直径在50nm～1mm(尤其是2-200微米粒径的范围更好)的范围。核壳结构复合金属球的球形度高，表面质量好，可以满足在在粉末冶金、导电浆料、硬质合金、磁性材料、传感、光学、催化等领域的广泛应用。The invention has the beneficial effects that the composite metal powder precursor is separated by the carbon material powder or by the ceramic material powder, and the metal droplets are not wetted or low-wet, non-diffused or less diffused at the carbon material or at the solid interface of the ceramic material. The nature of the liquid-solid interface droplets at the liquid-solid interface and the surface tension of the droplets at the liquid-gas interface simultaneously form spherical metal droplets. At the same time, the liquid phase is incompatible by melting with the composite metal, or a part of the metal is melted by the composite metal. The liquid-solid phase coexists, the liquid phase and the solid phase are mutually insoluble or low-miscible, and the layered coating is realized by the interaction of the surface energy and the liquid-solid two-phase interface energy, and the micro-shell of the core-shell structure is obtained after cooling. Nano composite metal ball. According to the invention, the principle of preparing the core-shell composite metal sphere is clear, the method for manufacturing the core-shell composite metal spherical powder is simple, the manufacturing cost is low, the production efficiency is high, and the method is simple, environmentally friendly, and can be mass-produced. A method for producing a core-shell micron and nano composite metal spherical powder. The core-shell composite metal spheres produced have a diameter of less than 10 mm, preferably a sphere diameter of 50 nm to 1 mm (especially a range of 2-200 micron particle diameters). The core-shell composite metal sphere has high sphericity and good surface quality, and can be widely used in powder metallurgy, conductive paste, cemented carbide, magnetic materials, sensing, optics, and catalysis.

附图说明DRAWINGS

图1通过本发明的制造方法采用铜铁氧体还原的铁/铜复合粉末为前驱物得到的核壳结构Fe/Cu微米球粉的扫描电子显微镜照片；Figure 1 is a scanning electron micrograph of a core-shell structure Fe/Cu microsphere powder obtained by using the copper ferrite reduced iron/copper composite powder as a precursor by the manufacturing method of the present invention;

图2通过本发明的制造方法采用铜铁氧体还原的铁/铜复合粉末为前驱物得到的核壳 结构Fe/Cu微米球粉的断面金相图Figure 2 is a core shell obtained by using a copper ferrite reduced iron/copper composite powder as a precursor by the manufacturing method of the present invention. Cross-section metallographic diagram of structured Fe/Cu microsphere powder

图3通过本发明的制造方法采用氢氧化铜和氢氧化铁共还原的铁/铜复合粉末为前驱物得到的核壳结构Fe/Cu微米球粉的扫描电子显微镜照片；Figure 3 is a scanning electron micrograph of a core-shell structure Fe/Cu microsphere powder obtained by using the copper/iron hydroxide co-reduced iron/copper composite powder as a precursor by the production method of the present invention;

图4通过本发明的制造方法采用氢氧化铜和氢氧化铁共还原的铁/铜复合粉末为前驱物得到的核壳结构Fe/Cu微米球粉的断面金相图；Figure 4 is a cross-sectional metallographic view of a core-shell structured Fe/Cu microsphere powder obtained by using the iron/copper composite powder in which copper hydroxide and ferric hydroxide are co-reduced as a precursor by the production method of the present invention;

图5通过本发明的制造方法得到的核壳结构Fe/Ag微米球粉的扫描电子显微镜照片；Figure 5 is a scanning electron micrograph of a core-shell structured Fe/Ag microsphere powder obtained by the manufacturing method of the present invention;

图6通过本发明的制造方法得到的核壳结构Fe/Ag微米球粉的背散射扫描电子显微镜照片；Figure 6 is a backscattered scanning electron micrograph of a core-shell structured Fe/Ag microsphere powder obtained by the manufacturing method of the present invention;

图7通过本发明的制造方法采用微米电解铜粉和纳米银粉混合的铜/银复合粉末为前驱物得到的核壳结构富Cu合金/富Ag合金微米球粉的扫描电子显微镜照片；Figure 7 is a scanning electron micrograph of a core-shell structure Cu-rich alloy/Ag-rich microsphere powder obtained by using the copper/silver composite powder of micron electrolytic copper powder and nano silver powder as a precursor by the manufacturing method of the present invention;

图8通过本发明的制造方法采用微米电解铜粉和纳米银粉混合的铜/银复合粉末为前驱物得到的核壳结构富Cu合金/富Ag合金微米球粉(a、b列分别对应不同配比的富Cu合金/富Ag)的电子图像和断面里外能谱图；Fig. 8 is a core-shell structure Cu-rich alloy/Ag-rich microsphere powder obtained by using the copper/silver composite powder of micron electrolytic copper powder and nano silver powder as a precursor by the manufacturing method of the present invention (the columns a and b respectively correspond to different types) Electronic image of the ratio of Cu-rich alloy/Ag-rich and cross-sectional energy spectrum;

图9通过本发明的制造方法采用微米电解铜粉和纳米银粉混合的铜/银复合粉末为前驱物得到的核壳结构富Cu合金/富Ag合金微米球粉的断面铜和银元素分布电子图；Figure 9 is a diagram showing the distribution of copper and silver elements in the core-shell structure Cu-rich alloy/Ag-rich microsphere powder obtained by using the copper/silver composite powder mixed with micron electrolytic copper powder and nano silver powder as the precursor by the manufacturing method of the present invention. ;

图10通过本发明的制造方法采用乙酸铜和乙酸银还原的铜/银复合粉末为前驱物得到的核壳结构富Cu合金/富Ag合金微米球粉的扫描电子显微镜照片；Figure 10 is a scanning electron micrograph of a core-shell structure Cu-rich alloy/Ag-rich microsphere powder obtained by using the copper/silver composite powder reduced by copper acetate and silver acetate as a precursor by the production method of the present invention;

图11通过本发明的制造方法采用乙酸铜、乙酸镍和乙酸银还原的铜/镍/银复合粉末为前驱物得到的核壳结构富CuNi合金/富Ag合金微米球粉的扫描电子显微镜照片。Fig. 11 is a scanning electron micrograph of a core-shell structure CuNi-rich alloy/Ag-rich microsphere powder obtained by using the copper/nickel/silver composite powder reduced by copper acetate, nickel acetate and silver acetate as a precursor by the production method of the present invention.

具体实施方式detailed description

如上所述，本申请将复合金属粉末前驱物用碳材料粉末或用陶瓷材料粉末隔开，利用金属液滴在碳材料或在陶瓷材料固体界面不润湿或低润湿、不扩散或少扩散的性质，在液固界面液滴的界面张力和液气界面液滴表面张力同时作用下形成球形金属液滴；同时，利用复合金属熔化后液相不相溶，或利用复合金属中部分金属熔化，液固相共存，液相和固相之间不互溶或低互溶的特点，在表面能和液固两相的界面能共同作用下实现分层包覆，冷却后获得核壳结构微米和纳米复合金属球。以下，对本发明的核壳结构微米和纳米复合金属球形粉末的制造方法进行详细的说明。As described above, the present application separates the composite metal powder precursor from the carbon material powder or the ceramic material powder, and utilizes the metal droplets to be non-wetting or low-wetting, non-diffusion or less diffusion at the carbon material or at the solid interface of the ceramic material. The nature of the liquid-solid interface droplets at the liquid-solid interface and the surface tension of the droplets at the liquid-gas interface simultaneously form spherical metal droplets; at the same time, the liquid phase is incompatible by melting with the composite metal, or is melted by partial metal in the composite metal. The liquid-solid phase coexists, the liquid phase and the solid phase are mutually insoluble or miscible, and the layered coating is realized by the interaction of the surface energy and the liquid-solid two-phase interface energy, and the core-shell structure micron and nanometer are obtained after cooling. Composite metal ball. Hereinafter, a method for producing the core-shell micro- and nano-composite metal spherical powder of the present invention will be described in detail.

本发明首先将制备所需尺寸的复合金属粉末前驱物。制备复合金属粉末前驱物：1)将两种或两种以上的金属粉末通过混合获得均匀的复合粉末；2)通过熔炼获得复 合金属，破碎成复合金属粉末，3)对有良好韧性的金属可以快淬成条带后破碎成复合金属粉末；4)通过混合不同的金属氧化物或金属盐得到均匀的复合氧化物或金属盐，还原后获得均匀的复合金属粉末；5)通过电化学反应或其他方法包覆的复合金属粉末；6)除了制备金属粉末外，也可以通过其他方式获得所需尺寸的复合金属粉末。The present invention first prepares a composite metal powder precursor of the desired size. Preparation of composite metal powder precursor: 1) two or more metal powders are mixed to obtain a uniform composite powder; 2) obtained by smelting Metal, broken into composite metal powder, 3) metal with good toughness can be quickly quenched into strips and then broken into composite metal powder; 4) by mixing different metal oxides or metal salts to obtain a uniform composite oxide or metal The salt, after reduction, obtains a uniform composite metal powder; 5) a composite metal powder coated by an electrochemical reaction or other methods; 6) In addition to the preparation of the metal powder, the composite metal powder of a desired size can also be obtained by other means.

将复合金属粉末前驱物与适当尺寸和数量的碳材料粉末或陶瓷材料粉末均匀混合，以达到用碳材料粉末或用陶瓷材料粉末隔开复合金属粉末前驱物的目的。准备复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末的方法有：1)将复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末混合的方法,i)采取机械方法均匀混合；ii)在液体(水、乙醇等)中搅拌均匀混合；iii)通过分散剂辅助分散后，与碳材料粉末或陶瓷材料粉末混合，混合后干燥得到用碳材料或用陶瓷材料包覆的金属颗粒的均匀的混合粉末；2)用以上方式将金属氧化物或金属盐与碳材料粉末或与陶瓷材料粉末混合，在还原气氛中(如氢气、氨气、一氧化碳、它们的混合气体等)退火，得到复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末。The composite metal powder precursor is uniformly mixed with a suitable size and amount of carbon material powder or ceramic material powder to achieve the purpose of separating the composite metal powder precursor with the carbon material powder or with the ceramic material powder. The method for preparing a composite metal powder precursor and a carbon material powder or a ceramic powder uniformly mixed powder is as follows: 1) a method of mixing a composite metal powder precursor with a carbon material powder or a ceramic material powder, i) adopting a mechanical method uniformity Mixing; ii) mixing uniformly in a liquid (water, ethanol, etc.); iii) assisting dispersion by a dispersing agent, mixing with a carbon material powder or a ceramic material powder, mixing and drying to obtain a carbon material or a ceramic material. a uniform mixed powder of metal particles; 2) mixing the metal oxide or metal salt with the carbon material powder or the ceramic material powder in the above manner, in a reducing atmosphere (such as hydrogen, ammonia, carbon monoxide, a mixed gas thereof, etc.) Annealing to obtain a uniformly mixed powder of the composite metal powder precursor and the carbon material powder or the ceramic material powder.

将混合均匀的复合金属粉末前驱物/碳材料或陶瓷材料混合粉末在真空或气氛(包括氢气、氨气、氮气、氩气和它们的混合气体等)中热处理，温度：至少达到所述复合金属前驱物中一种金属的熔融温度，优选的温度为高于该金属熔点40～100℃；保温时间：保证一种或一种以上金属完全熔化，优选时间为4min～10min。短时保温可以降低金属液滴与碳材料或陶瓷材料之间的相互扩散，保证金属液滴在碳材料或陶瓷材料界面的不润湿性或低润湿性；冷却方式：1)快冷，让复合金属颗粒保持液态金属球的形状，同时，可以克服合金材料成分宏观偏析和减少高温下碳材料或陶瓷材料向金属颗粒的扩散。2)快冷结合缓慢冷却，快冷到熔点一下温度后，再缓慢冷却，可以获到结晶度好的核壳结构的复合微米和纳米金属球。Mixing the uniformly mixed composite metal powder precursor/carbon material or ceramic material mixed powder in a vacuum or atmosphere (including hydrogen, ammonia, nitrogen, argon, and a mixed gas thereof, etc.) at a temperature of at least the composite metal The melting temperature of a metal in the precursor, preferably at a temperature higher than 40-100 ° C of the melting point of the metal; holding time: ensuring that one or more metals are completely melted, preferably for a period of 4 min to 10 min. Short-time insulation can reduce the interdiffusion between metal droplets and carbon materials or ceramic materials, and ensure the non-wetting or low wettability of metal droplets at the interface of carbon materials or ceramic materials; cooling method: 1) fast cooling, The composite metal particles are maintained in the shape of a liquid metal sphere, and at the same time, the macrosegregation of the alloy material composition can be overcome and the diffusion of the carbon material or the ceramic material to the metal particles at a high temperature can be reduced. 2) Quick cooling combined with slow cooling, cooling to the melting point and then slowly cooling, can obtain composite micron and nano metal spheres with good crystallinity.

将热处理的复合金属粉末前驱物/碳材料或陶瓷材料混合粉末中的碳材料粉末或陶瓷材料粉末除掉，获得核壳结构微米和纳米复合金属球形粉末。清洗方法包括：1)在液体(如：水或有机溶剂等)中浸泡后，利用核壳结构复合金属与碳材料或与陶瓷材料大的密度差，超声清洗，除掉碳材料粉末或陶瓷材料粉末，获得核壳结构复合金属球形粉末；2)在液体中浸泡后，采用离心、过滤或外加磁场的方法获得核壳结构复合金属球形粉末；3)利用核壳结构复合金属颗粒与碳材料或与陶瓷材料的形状、大小不同，使用合适的筛子将二者分离。 The carbon material powder or the ceramic material powder in the heat-treated composite metal powder precursor/carbon material or ceramic material mixed powder is removed to obtain a core-shell structured micro- and nano-composite metal spherical powder. The cleaning method includes: 1) after immersing in a liquid (such as water or an organic solvent), using a core-shell composite metal and a carbon material or a ceramic material having a large difference in density, ultrasonic cleaning, removing carbon material powder or ceramic material Powder, obtaining a core-shell composite metal spherical powder; 2) obtaining a core-shell composite metal spherical powder by centrifugation, filtration or external magnetic field after immersion in a liquid; 3) using a core-shell structure composite metal particle and carbon material or Different from the shape and size of the ceramic material, the two are separated by a suitable sieve.

另外，本发明的核壳结构复合金属球形粉末的制造方法最适用于直径为50nm～1mm的金属球形粉末。在直径大于1mm的情况下，由于被熔化后，球状化的液滴由于自身的重力作用，球形度会变差，在冷却过程中难以得到球形度高的复合金属球，因此，复合金属球形粉末的直径优选在1mm以下。另一方面，虽然颗粒尺寸越小，越易获得球形度高的颗粒，但细小的核壳结构复合金属球粉由于热处理后与碳材料粉末或陶瓷材料粉末分离的难度变大，因此核壳结构复合金属球形粉末的直径优选在50nm以上。Further, the method for producing a core-shell structured composite metal spherical powder of the present invention is most suitable for a metal spherical powder having a diameter of 50 nm to 1 mm. In the case where the diameter is larger than 1 mm, since the spheroidized droplets are melted, the sphericity is deteriorated due to their own gravity, and it is difficult to obtain a composite metal sphere having a high sphericity during the cooling process. Therefore, the composite metal spherical powder The diameter is preferably 1 mm or less. On the other hand, although the smaller the particle size, the more spherical particles are more easily obtained, the fine core-shell composite metal spherical powder is more difficult to separate from the carbon material powder or the ceramic material powder after heat treatment, so the core-shell structure The diameter of the composite metal spherical powder is preferably 50 nm or more.

实施例1Example 1

核壳结构铁/铜复合金属微米球形粉末的制备。采用金属氧化物为原料，按所需铜铁氧体组分的原子百分比(Cu:Fe＝1:2)称量氧化铜和三氧化二铁粉末并均匀混合后压片，在800℃退火6小时，再机械研磨均匀化后压片，在800℃退火3小时获得均匀的铜铁氧体。取2克铜铁氧体片，机械粉碎到尺寸为20微米左右的粉末，将铜铁氧体粉末与尺寸为400nm左右的石墨粉，按质量比1:1配比，机械搅拌，再次均匀混合。Preparation of core-shell structured iron/copper composite metal micro-spherical powder. The metal oxide is used as a raw material, and the copper oxide and the ferric oxide powder are weighed according to the atomic percentage of the required copper ferrite component (Cu:Fe=1:2) and uniformly mixed, and then compressed, and annealed at 800 ° C. After an hour, it was mechanically ground and homogenized, and then pressed, and annealed at 800 ° C for 3 hours to obtain a uniform copper ferrite. Take 2 grams of copper ferrite sheets, mechanically pulverize them to a powder with a size of about 20 microns, and mix the copper ferrite powder with graphite powder with a size of about 400 nm at a mass ratio of 1:1, mechanically stir, and evenly mix again. .

将上述混合后的铜铁氧铁粉/石墨粉的混合粉末装入氧化铝坩埚中，坩埚放进退火炉加热区，抽真空到6×10^-3Pa,通入0.01Mpa的氢气和0.03Mpa的氩气,加热到800℃进行还原，保温60分钟后，得到铁/铜均匀的复合粉末前驱物。之后，抽真空到5.4Pa，再通入0.02Mpa的氩气，将退火炉加热区加热到1100℃(高于铜的熔点)，保温10分钟后，将坩埚拉出加热区冷却。The mixed powder of the mixed copper ferrite powder/graphite powder is placed in an alumina crucible, placed in a heating zone of the annealing furnace, evacuated to 6×10 ^-3 Pa, and pressurized with 0.01 Mpa of hydrogen and 0.03 Mpa. Argon gas was heated to 800 ° C for reduction, and after 60 minutes of heat retention, an iron/copper uniform composite powder precursor was obtained. Thereafter, the vacuum was evacuated to 5.4 Pa, and argon gas of 0.02 MPa was introduced, and the heating zone of the annealing furnace was heated to 1100 ° C (higher than the melting point of copper). After the heat retention for 10 minutes, the crucible was pulled out of the heating zone to be cooled.

用水浸泡混合粉末，通过超声和磁场条件下清洗，得到铜包铁核壳结构的微米球形粉末。图1为得到的核壳结构复合金属球的外观扫描电子显微镜照片。图2为得到的核壳结构复合金属球断面金相图。根据本发明核壳结构复合金属球形粉末的制造方法，确认能够得到铜包铁的核壳结构复合金属微米球。The mixed powder was soaked in water and washed under ultrasonic and magnetic fields to obtain a micro-spherical powder of a copper-coated iron core-shell structure. Fig. 1 is a scanning electron micrograph of the appearance of the obtained core-shell composite metal sphere. Fig. 2 is a metallographic view of the obtained core-shell composite metal sphere. According to the method for producing a core-shell composite metal spherical powder of the present invention, it was confirmed that a core-shell composite metal microsphere having a copper-coated iron can be obtained.

实施例2Example 2

核壳结构铁/铜复合金属微米球形粉末的制备。Preparation of core-shell structured iron/copper composite metal micro-spherical powder.

采用金属盐为原料，按所需铜铁的原子百分比(Cu:Fe＝1:1)称量乙酸铜和三氯化铁，溶解于去离子水里，并持续搅拌。在搅拌过程中逐渐滴加过量的氢氧化钾溶液，乙酸铜和三氯化铁混合溶液逐渐变成浑浊，反应生成铜和铁氢氧化物沉淀。将沉淀过滤，并用大量去离子水清洗去除其他离子和杂质后干燥。将干燥好的氢氧化铁和氢氧 化铜沉淀研磨后成细粉，并和400nm的石墨粉混合均匀。Using a metal salt as a raw material, copper acetate and ferric chloride were weighed according to the atomic percentage of copper and iron required (Cu:Fe=1:1), dissolved in deionized water, and continuously stirred. An excessive amount of potassium hydroxide solution was gradually added dropwise during the stirring, and the mixed solution of copper acetate and ferric chloride gradually became cloudy, and the reaction formed copper and iron hydroxide precipitates. The precipitate was filtered and washed with a large amount of deionized water to remove other ions and impurities and dried. Dry iron hydroxide and hydrogen The copper precipitated and ground to form a fine powder, and was uniformly mixed with the 400 nm graphite powder.

将上述混合后的氢氧化铁、氢氧化铜和石墨的混合粉末装入氧化铝坩埚中，按实施例1所述的步骤操作。制备所得的铜包铁核壳结构的微米球形粉末扫描电镜如图3所示，其断面金相图如图4所示，确认能够得到铜包铁核壳结构复合金属微米球。The mixed powder of the above-mentioned mixed iron hydroxide, copper hydroxide and graphite was placed in an alumina crucible and operated in the same manner as in Example 1. The micro-spherical powder scanning electron microscope prepared by the obtained copper-clad iron core-shell structure is shown in FIG. 3, and the cross-sectional metallographic figure is shown in FIG. 4, and it is confirmed that the copper-coated iron core-shell composite metal microspheres can be obtained.

实施例3Example 3

核壳结构铁/银复合金属微米球形粉末的制备。Preparation of core-shell structured iron/silver composite metal micro-spherical powder.

采用乙酸银和硝酸铁为原料，将按铁和银的原子百分比(Fe:Ag＝2:1)称量硝酸铁和乙酸银，在去离子水里加热和搅拌制备成乙酸银和硝酸铁混合溶液。在搅拌过程中逐渐滴加过量的氢氧化钾溶液，反应生成铁和银沉淀粉末。将沉淀过滤，并用大量去离子水清洗去除其他离子和杂质后干燥。将干燥好的氢氧化铁和氧化银沉淀研磨后成细粉，并和400nm的石墨粉混合均匀。Using silver acetate and ferric nitrate as raw materials, ferric nitrate and silver acetate are weighed according to the atomic percentage of iron and silver (Fe:Ag=2:1), and heated and stirred in deionized water to prepare a mixture of silver acetate and ferric nitrate. Solution. An excessive amount of potassium hydroxide solution was gradually added dropwise during the stirring to form an iron and silver precipitated powder. The precipitate was filtered and washed with a large amount of deionized water to remove other ions and impurities and dried. The dried ferric hydroxide and silver oxide were precipitated and ground to form a fine powder, and uniformly mixed with 400 nm of graphite powder.

将上述混合后的氢氧化铁和氧化银粉/石墨粉的混合粉末装入氧化铝坩埚中。将坩埚放进退火炉加热区，抽真空到6×10^-3Pa后,通入0.01Mpa的氢气和0.03Mpa的氩气,加热到800℃进行还原，保温60分钟后，得到铁/银均匀的复合粉末前驱物。之后，抽真空到5.4Pa，再通入0.02Mpa的氩气，将退火炉加热区加热到1050℃(高于银的熔点)，保温10分钟后，将坩埚拉出加热区冷却。The mixed powder of the above-mentioned mixed iron hydroxide and silver oxide powder/graphite powder was placed in an alumina crucible. Put the crucible into the heating zone of the annealing furnace, evacuate to 6×10 ^-3 Pa, pass 0.01Mpa of hydrogen and 0.03Mpa of argon, heat to 800 °C for reduction, and keep warm for 60 minutes to obtain iron/silver uniform. Composite powder precursor. Thereafter, the vacuum was evacuated to 5.4 Pa, and argon gas of 0.02 MPa was introduced, and the heating zone of the annealing furnace was heated to 1050 ° C (higher than the melting point of silver). After the heat preservation for 10 minutes, the crucible was pulled out of the heating zone to be cooled.

用酒精浸泡混合粉末，通过超声和磁场条件下清洗，得到银包铁核壳结构的微米球形粉末。图5和图6为得到的复合金属粉末的外观扫描电子显微镜照片和背散射电子图像，从背散射电子图像可以看出金属银包覆在金属铁的表面。其断面金相图类似于图2。根据本发明核壳结构复合金属球形粉末的制造方法，确认能够得到银包铁核壳结构复合金属微米球。The mixed powder was soaked with alcohol, and washed under ultrasonic and magnetic fields to obtain a micro-spherical powder of a silver-coated iron core-shell structure. Fig. 5 and Fig. 6 are scanning electron micrographs and backscattered electron images of the obtained composite metal powder, and it can be seen from the backscattered electron image that the metallic silver is coated on the surface of the metallic iron. Its section metallographic diagram is similar to Figure 2. According to the method for producing a core-shell composite metal spherical powder of the present invention, it was confirmed that a silver-coated iron core-shell composite metal microsphere can be obtained.

实施例4Example 4

核壳结构富铜合金/富银合金复合微米球形粉末的制备。Preparation of core-shell structure copper-rich alloy/silver-rich alloy composite micro-spherical powder.

采用纳米银粉和微米铜粉为原料，将100纳米左右的银粉和5微米左右的电解铜粉按重量比1:4进行称量。在少量无水酒精中超声分散30分钟后，边搅拌边蒸干酒精，得到铜/银复合粉末前驱物。将铜/银复合粉末前驱物与尺寸为400nm左右的石墨粉，按质量比1:1配比，机械搅拌，再次均匀混合。Using nano silver powder and micron copper powder as raw materials, silver powder of about 100 nanometers and electrolytic copper powder of about 5 micrometers were weighed at a weight ratio of 1:4. After ultrasonic dispersion in a small amount of anhydrous alcohol for 30 minutes, the alcohol was evaporated to dryness with stirring to obtain a copper/silver composite powder precursor. The copper/silver composite powder precursor and the graphite powder having a size of about 400 nm were mechanically stirred and uniformly mixed again at a mass ratio of 1:1.

将混合好的将上述混合后的银铜粉/石墨粉的混合粉末装入氧化铝坩埚中，坩埚放进退火炉的非加热区。抽真空到6×10^-3Pa后，通入0.02Mpa的氩气,将退火炉加热区 加热到1050℃，推入装有银铜混合粉/石墨混合粉末的坩埚到1050℃(高于银的熔点)的加热区，保温10分钟后，将坩埚拉出加热区冷却。The mixed powder of the above-mentioned mixed silver-copper powder/graphite powder was placed in an alumina crucible and placed in a non-heating zone of the annealing furnace. After evacuating to 6×10 ^-3 Pa, argon gas of 0.02 MPa is introduced, the heating zone of the annealing furnace is heated to 1050 ° C, and the crucible containing the silver-copper mixed powder/graphite mixed powder is pushed to 1050 ° C (higher than silver). The melting point of the heating zone, after 10 minutes of incubation, the crucible is pulled out of the heating zone to cool.

制备得到了富银合金包富铜合金的核壳结构的微米球形粉末，其颜色偏银白色，图7为得到的核壳结构复合金属球的外观扫描电子显微镜照片，其断面的铜和银元素分布如图8和图9，确认能够得到富银合金包覆富铜合金的核壳结构复合金属微米球。The micro-spherical powder of the core-shell structure of the silver-rich alloy-coated copper-rich alloy was prepared, and its color was silvery white. Figure 7 is a scanning electron micrograph of the obtained core-shell composite metal sphere, and the copper and silver elements of the cross section were obtained. As shown in Fig. 8 and Fig. 9, it was confirmed that a core-shell composite metal microsphere in which a silver-rich alloy was coated with a copper-rich alloy was obtained.

实施例5Example 5

核壳结构富铜合金/富银合金复合金属微米球形粉末的制备。Preparation of core-shell structure copper-rich alloy/silver-rich alloy composite metal micro-spherical powder.

采用乙酸银和乙酸铜为原料，将按银和铜的原子百分比(Ag:Cu＝1:2)进行称量乙酸银和乙酸铜。将乙酸银和乙酸铜溶解于热水中并持续搅拌。在搅拌过程中逐渐滴加过量的氢氧化钾溶液，反应生成铜和银沉淀粉末。将沉淀过滤，并用大量去离子水清洗去除其他离子和杂质后干燥。将干燥好的氢氧化铜和氧化银沉淀研磨后成细粉，并和400nm的石墨粉混合均匀。Using silver acetate and copper acetate as raw materials, silver acetate and copper acetate were weighed in atomic percentages of silver and copper (Ag: Cu = 1:2). Silver acetate and copper acetate were dissolved in hot water and stirring was continued. An excessive amount of potassium hydroxide solution was gradually added dropwise during the stirring to form a copper and silver precipitated powder. The precipitate was filtered and washed with a large amount of deionized water to remove other ions and impurities and dried. The dried copper hydroxide and silver oxide were precipitated and ground to form a fine powder, and uniformly mixed with 400 nm of graphite powder.

将上述混合后的氢氧化铜和氧化银粉/石墨粉的混合粉末装入氧化铝坩埚中，坩埚放进退火炉加热区，抽真空到6×10^-3Pa,通入0.01Mpa的氢气和0.03Mpa的氩气,加热到600℃进行还原，保温60分钟后，得到铜/银均匀的复合粉末前驱物。之后，抽真空到5.4Pa，再通入0.02Mpa的氩气，将退火炉加热区加热到1030℃(高于银的熔点)，保温10分钟后，将坩埚拉出加热区冷却。The mixed powder of the above mixed copper hydroxide and silver oxide powder/graphite powder is placed in an alumina crucible, placed in a heating zone of the annealing furnace, evacuated to 6×10 ^-3 Pa, and 0.01 Mpa of hydrogen and 0.03 Mpa are introduced. The argon gas was heated to 600 ° C for reduction, and after 60 minutes of heat retention, a copper/silver uniform composite powder precursor was obtained. Thereafter, the vacuum was evacuated to 5.4 Pa, and argon gas of 0.02 MPa was introduced, and the heating zone of the annealing furnace was heated to 1030 ° C (higher than the melting point of silver). After the heat retention for 10 minutes, the crucible was pulled out of the heating zone to be cooled.

用酒精浸泡混合粉末，通过超声下清洗，得到银包铜核壳结构的微米球形粉末。其颜色偏银白色，图10为得到的复合金属球的外观扫描电子显微镜照片，断面的铜和银元素分布类似图8和图9。根据本发明核壳结构复合金属球形粉末的制造方法，确认能够得到富银包富铜核壳结构复合微米球。The mixed powder was soaked with alcohol and washed by ultrasonication to obtain a micro-spherical powder of a silver-coated copper core-shell structure. The color is silvery white, and Fig. 10 is a scanning electron micrograph of the appearance of the obtained composite metal sphere. The copper and silver elements of the cross section are similar to those of Figs. 8 and 9. According to the method for producing a core-shell composite metal spherical powder of the present invention, it was confirmed that a silver-rich copper-rich core-shell composite microsphere can be obtained.

实施例6Example 6

核壳结构富铜镍合金/富银合金复合微米球形粉末的制备。Preparation of core-shell structure copper-rich nickel alloy/silver-rich alloy composite micro spherical powder.

采用乙酸银、乙酸铜和乙酸镍为原料，将按银、铜和镍的原子百分比(Ag:Cu:Ni＝4:5:1)进行称量乙酸银、乙酸铜和乙酸镍。将乙酸银、乙酸铜和乙酸镍溶解于75度热水中并持续搅拌。在搅拌过程中逐渐滴加过量的氢氧化钾溶液，反应生成氧化银、氢氧化铜和氢氧化镍沉淀粉末。将沉淀过滤，并用大量去离子水清洗去除其他离子和杂质后干燥。将干燥好的氧化银、氢氧化铜和氢氧化镍混合粉末研磨成细粉，并和400nm的石墨粉混合均匀。 Silver acetate, copper acetate and nickel acetate were weighed in terms of atomic percentages of silver, copper and nickel (Ag: Cu: Ni = 4:5:1) using silver acetate, copper acetate and nickel acetate as raw materials. Silver acetate, copper acetate and nickel acetate were dissolved in hot water at 75 degrees and stirring was continued. An excessive amount of potassium hydroxide solution was gradually added dropwise during the stirring to form a precipitated powder of silver oxide, copper hydroxide and nickel hydroxide. The precipitate was filtered and washed with a large amount of deionized water to remove other ions and impurities and dried. The dried mixed powder of silver oxide, copper hydroxide and nickel hydroxide was ground into a fine powder and uniformly mixed with 400 nm of graphite powder.

将上述混合后的氧化银、氢氧化铜、氢氧化镍和石墨粉的混合粉末装入氧化铝坩埚中，坩埚放进退火炉加热区，抽真空到6×10^-3Pa,通入0.01Mpa的氢气和0.03Mpa的氩气,加热到600℃进行还原，保温60分钟后，得到铜/镍/银均匀的复合粉末前驱物。之后，抽真空到5.4Pa，再通入0.02Mpa的氩气，将退火炉加热区加热到1050℃(高于银的熔点)，保温10分钟后，将坩埚拉出加热区冷却。The mixed powder of the above mixed silver oxide, copper hydroxide, nickel hydroxide and graphite powder is placed in an alumina crucible, placed in a heating zone of the annealing furnace, evacuated to 6×10 ^-3 Pa, and passed through 0.01 Mpa. Hydrogen and 0.03 MPa of argon were heated to 600 ° C for reduction, and after 60 minutes of incubation, a copper/nickel/silver uniform composite powder precursor was obtained. Thereafter, the vacuum was evacuated to 5.4 Pa, and argon gas of 0.02 MPa was introduced, and the heating zone of the annealing furnace was heated to 1050 ° C (higher than the melting point of silver). After the heat preservation for 10 minutes, the crucible was pulled out of the heating zone to be cooled.

用酒精浸泡混合粉末，通过超声下清洗，得到富银合金包富铜镍合金核壳结构的微米球形粉末。其颜色偏银白色，图11为得到的复合金属球的外观扫描电子显微镜照片，断面结构类似图2和图4。根据本发明核壳结构复合金属球形粉末的制造方法，确认能够得到富银合金包富铜镍合金的核壳结构复合金属微米球。 The mixed powder is soaked with alcohol and washed by ultrasonication to obtain a micro-spherical powder of a silver-rich alloy-coated copper-nickel alloy core-shell structure. The color is silvery white, and FIG. 11 is a scanning electron micrograph of the appearance of the obtained composite metal ball, and the cross-sectional structure is similar to FIG. 2 and FIG. According to the method for producing a core-shell composite metal spherical powder of the present invention, it was confirmed that a core-shell composite metal microsphere having a silver-rich alloy-enriched copper-nickel alloy can be obtained.

Claims (10)

1. 核壳结构微米和纳米复合金属球形粉末的制造方法，其特征在于，包括如下步骤：A method for producing a core-shell micron and nano composite metal spherical powder, comprising the steps of:

   (1)准备复合金属粉末前驱物；(1) preparing a composite metal powder precursor;

   (2)准备的复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末；(2) a uniformly mixed powder of the prepared composite metal powder precursor with a carbon material powder or with a ceramic material powder;

   (3)高温热处理使复合金属前驱物中一种以上的金属熔融，凝固后形成核壳结构复合金属球；高温热处理温度至少达到所述复合金属前驱物中一种金属的熔融温度，尤其是温度在该金属熔点以上40℃到100℃的范围内；(3) high temperature heat treatment causes more than one metal in the composite metal precursor to melt and solidify to form a core-shell composite metal sphere; the high temperature heat treatment temperature reaches at least the melting temperature of a metal in the composite metal precursor, especially the temperature Within the range of 40 ° C to 100 ° C above the melting point of the metal;

   (4)除掉碳材料粉末或陶瓷材料粉末获得核壳结构微米和纳米复合金属球形粉末；所述复合金属粉末前驱物尺寸小于10mm,优选尺寸范围在50nm～1mm。(4) The carbon material powder or the ceramic material powder is removed to obtain a core-shell microstructure micron and nano composite metal spherical powder; the composite metal powder precursor has a size of less than 10 mm, preferably a size ranging from 50 nm to 1 mm.
2. 根据权利要求1所述的具有核壳结构的微米和纳米复合金属球形粉末的制造方法，其特征在于：The method for producing a micro- and nano-composite metal spherical powder having a core-shell structure according to claim 1, wherein:

   具有核壳结构球形粉末的复合金属包括：1)液态时某一温度区间存在两种或两种以上不相溶液相的金属，包括：铁或铁基合金)/铜或铜基合金、铁或铁基合金/银或银基合金、钴或钴基合金/银或银基合金、镍或镍基合金/银或银基合金、钨或钨基合金/铜或铜基合金、钨或钨基合金/银或银基合金、碳化钨/铜或铜基合金、碳化钨/银或银基合金、铁或铁基合金/铋或铋基合金、钴或钴基合金/铋或铋基合金；2)两种或两种以上液态相溶，固态不固溶或低固溶，即在某一温度区间，存在液、固相共存的金属，包括：银或银基合金/铜或铜基合金、铝或铝基合金/硅或硅基合金、锡或锡基合金/铋或铋基合金、铜或铜基合金/铋或铋基合金、钴或钴基合金/铜或铜基合金、金或金基合金/铜或铜基合金。A composite metal having a core-shell structured spherical powder includes: 1) a metal having two or more incompatible phase phases in a certain temperature range in a liquid state, including: iron or an iron-based alloy) / copper or a copper-based alloy, iron or Fe-based alloy/silver or silver based alloy, cobalt or cobalt based alloy/silver or silver based alloy, nickel or nickel based alloy/silver or silver based alloy, tungsten or tungsten based alloy/copper or copper based alloy, tungsten or tungsten based Alloy/silver or silver based alloy, tungsten carbide/copper or copper based alloy, tungsten carbide/silver or silver based alloy, iron or iron based alloy/ruthenium or ruthenium based alloy, cobalt or cobalt based alloy/ruthenium or ruthenium based alloy; 2) Two or more liquids are compatible, solid solution is not solid solution or low solid solution, that is, in a certain temperature range, there are metals in which liquid and solid phases coexist, including: silver or silver-based alloy/copper or copper-based alloy , aluminum or aluminum based alloys / silicon or silicon based alloys, tin or tin based alloys / tantalum or niobium based alloys, copper or copper based alloys / tantalum or niobium based alloys, cobalt or cobalt based alloys / copper or copper based alloys, gold Or gold-based alloy / copper or copper-based alloy.
3. 根据权利要求1至2中任一项所述的具有核壳结构的微米和纳米复合金属球形粉末的制造方法，其特征在于：准备所述复合金属粉末前驱物原料包括：1)将两种或两种以上的金属粉末通过混合获得均匀的复合粉末；2)通过熔炼获得复合金属，破碎成复合金属粉末，3)快淬成条带后破碎成复合金属粉末；4)通过机械合金化获得的复合合金粉末；5)通过混合不同的金属氧化物或金属盐得到均匀的复合氧化物或金属盐，还原后获得均匀的复合金属粉末；6)通过电化学反应或其他方法包覆的复合金属粉末；7)通过其他方法获得的复合金属粉末。The method for producing a micro- and nano-composite metal spherical powder having a core-shell structure according to any one of claims 1 to 2, wherein the preparation of the composite metal powder precursor material comprises: 1) two or Two or more metal powders are mixed to obtain a uniform composite powder; 2) a composite metal is obtained by smelting, and is broken into a composite metal powder, 3) is rapidly quenched into a strip and then broken into a composite metal powder; 4) obtained by mechanical alloying. Composite alloy powder; 5) by mixing different metal oxides or metal salts to obtain a uniform composite oxide or metal salt, after reduction to obtain a uniform composite metal powder; 6) composite metal powder coated by electrochemical reaction or other methods ; 7) Composite metal powder obtained by other methods.
4. 根据权利要求1中所述的具有核壳结构的微米和纳米复合金属球形粉末的制造 方法，其特征在于：Manufacture of micro- and nano-composite metal spherical powders having a core-shell structure according to claim 1 Method, characterized in that:

   碳材料粉末为石墨、石墨烯、金刚石、碳粉或煤粉以及它们二种或二种以上的混合物；陶瓷材料粉末为碳化物陶瓷、硼化物陶瓷、氧化物陶瓷或氮化物陶瓷以及它们二种或二种以上的混合物。The carbon material powder is graphite, graphene, diamond, carbon powder or coal powder and a mixture of two or more kinds thereof; the ceramic material powder is a carbide ceramic, a boride ceramic, an oxide ceramic or a nitride ceramic, and both of them Or a mixture of two or more.
5. 根据权利要求1至5中任一项所述的具有核壳结构的微米和纳米金属球形粉末的制造方法，其特征在于：The method for producing a micron- and nano-metal spherical powder having a core-shell structure according to any one of claims 1 to 5, wherein:

   准备复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末的方法为下述之一，i)采取机械方法均匀混合；ii)在液体中搅拌均匀混合；iii)通过分散剂辅助分散后，与碳材料粉末或陶瓷材料粉末混合，混合后干燥得到用碳材料或用陶瓷材料包覆的复合金属粉末前驱物的均匀的混合粉末。The method of preparing the composite metal powder precursor and the carbon material powder or the ceramic powder uniformly mixed powder is one of the following, i) uniformly mixing by mechanical means; ii) stirring and mixing uniformly in the liquid; iii) assisting by dispersing agent After dispersion, it is mixed with a carbon material powder or a ceramic material powder, mixed and dried to obtain a uniform mixed powder of a composite metal powder precursor coated with a carbon material or a ceramic material.
6. 根据权利要求5所述的具有核壳结构的微米和纳米金属球形粉末的制造方法，其特征在于：用以上方式将两种或以上的金属氧化物或金属盐前驱物与碳材料粉末或与陶瓷材料粉末混合，在还原气氛中进行热处理，得到复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的均匀混合粉末。The method for producing a micron- and nano-metal spherical powder having a core-shell structure according to claim 5, wherein two or more metal oxide or metal salt precursors and carbon material powder or ceramic are used in the above manner The material powder is mixed and heat-treated in a reducing atmosphere to obtain a uniformly mixed powder of the composite metal powder precursor and the carbon material powder or the ceramic material powder.
7. 根据权利要求1至6中任一项所述的具有核壳结构的微米和纳米复合金属球形粉末的制造方法，其特征在于：The method for producing a micron- and nano-composite metal spherical powder having a core-shell structure according to any one of claims 1 to 6, wherein:

   将所述复合金属粉末前驱物用碳材料粉末或陶瓷材料粉末隔开；复合金属粉末前驱物与碳材料粉末或与陶瓷材料粉末的质量比应满足所称量的复合金属粉末前驱物的总表面积小于所配比的碳材料粉末或陶瓷材料粉末的总表面积；所述碳材料粉末或陶瓷材料粉末可以是任意大小的尺寸，10纳米-100微米粒径的范围更好；碳材料粉末或陶瓷材料粉末的形貌可以是片状、球状、线状、管状或其他形状。Separating the composite metal powder precursor with carbon material powder or ceramic material powder; the mass ratio of the composite metal powder precursor to the carbon material powder or the ceramic material powder should satisfy the total surface area of the weighed composite metal powder precursor Less than the total surface area of the proportioned carbon material powder or ceramic material powder; the carbon material powder or ceramic material powder may be any size, and the range of 10 nm to 100 μm particle diameter is better; carbon material powder or ceramic material The morphology of the powder can be in the form of flakes, spheres, wires, tubes or other shapes.
8. 根据权利要求1至7所述的具有核壳结构的微米和纳米复合金属球形粉末的制造方法，其特征在于：A method for producing a micron- and nano-composite metal spherical powder having a core-shell structure according to any one of claims 1 to 7, wherein:

   将混合均匀的复合金属粉末前驱物/碳材料或陶瓷材料混合粉末在真空或气氛(包括氢气、氮气、氩气和氨气等)中热处理，温度：至少达到所述复合金属前驱物中一种金属的熔融温度，优选的温度为高于该种金属熔点40～100℃；保温时间：保证金属完全熔化，优选时间为4～10分钟，短时保温克服金属液滴与碳材料或陶瓷材料之间的相互扩散，保证金属液滴在碳材料或陶瓷材料界面的不润湿性或低润湿性；冷却方式：1)快冷，让复合金属颗粒保持液态金属球的形状，同时，克服合金材料成 分宏观偏析和减少高温下碳材料或陶瓷材料向金属颗粒的扩散；2)快冷结合缓慢冷却，快冷到熔点以下温度后，再缓慢冷却，获到结晶度好的核壳结构微米和纳米复合金属球。Mixing the uniformly mixed composite metal powder precursor/carbon material or ceramic material mixed powder in a vacuum or atmosphere (including hydrogen, nitrogen, argon, ammonia, etc.) at a temperature of at least one of the composite metal precursors The melting temperature of the metal, preferably 40 to 100 ° C above the melting point of the metal; holding time: to ensure complete melting of the metal, preferably 4 to 10 minutes, short-term insulation against metal droplets and carbon or ceramic materials Interdiffusion to ensure non-wetting or low wetting of metal droplets at the interface of carbon or ceramic materials; cooling method: 1) rapid cooling, allowing composite metal particles to maintain the shape of liquid metal spheres, while overcoming alloys Material into Dividing macroscopic segregation and reducing the diffusion of carbon or ceramic materials to metal particles at high temperatures; 2) rapidly cooling combined with slow cooling, cooling to a temperature below the melting point, and then slowly cooling to obtain a core-shell structure with good crystallinity, micron and nanometer. Composite metal ball.
9. 根据权利要求1至8中任一项所述的具有核壳结构的微米和纳米复合金属球形粉末的制造方法，其特征在于：将高温热处理处理的复合金属/碳材料或陶瓷材料混合粉末中的碳材料粉末或陶瓷材料粉末分离，获得核壳结构微米和纳米复合金属球形粉末；分离方法包括：1)在液体中浸泡后，利用复合金属与碳材料或与陶瓷材料大的密度差，超声清洗，除掉碳材料粉末或陶瓷材料粉末，获得核壳结构复合金属球形粉末；2)在液体中浸泡后，采用离心、过滤或外加磁场的方法获得核壳结构复合金属球形粉末；3)利用核壳结构复合金属颗粒与碳材料或与陶瓷材料的形状、大小不同，使用合适的筛子将二者分离。The method for producing a micron- and nano-composite metal spherical powder having a core-shell structure according to any one of claims 1 to 8, wherein the high-temperature heat-treated composite metal/carbon material or ceramic material is mixed in powder The carbon material powder or the ceramic material powder is separated to obtain a core-shell micro- and nano-composite metal spherical powder; the separation method comprises: 1) ultrasonic immersion after immersion in a liquid, using a large difference in density between the composite metal and the carbon material or the ceramic material Removing the carbon material powder or the ceramic material powder to obtain the core-shell composite metal spherical powder; 2) after immersing in the liquid, obtaining the core-shell composite metal spherical powder by centrifugation, filtration or external magnetic field; 3) using the core The shell structure composite metal particles are different from the carbon material or the ceramic material in shape and size, and are separated by a suitable sieve.
10. 根据权利要求1、8或9中任一项所述的具有核壳结构的微米和纳米复合金属球形粉末的制造方法，其特征在于:The method for producing a micron- and nano-composite metal spherical powder having a core-shell structure according to any one of claims 1, 8 or 9, wherein:

    所制备的核壳结构的微米和纳米复合金属球形粉末颗粒包括内核和外壳；1)对于高温热处理时为不相溶的液相的复合金属：内核是热处理温度时液态表面能最大的金属，外壳是热处理温度时液态表面能最小的金属；2)对于高温热处理时为液、固相共存的复合金属：内核是热处理温度时为固相的金属，外壳是热处理温度时液相中表面能最小的金属。 The prepared core-shell micro- and nano-composite metal spherical powder particles include a core and an outer shell; 1) a composite metal which is incompatible liquid phase for high-temperature heat treatment: the core is the metal having the largest liquid surface energy at the heat treatment temperature, and the outer shell It is the metal with the smallest liquid surface energy at the heat treatment temperature; 2) The composite metal which is liquid and solid phase coexisting at the time of high temperature heat treatment: the core is a solid phase metal at the heat treatment temperature, and the outer shell is the surface energy of the liquid phase at the heat treatment temperature. metal.

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