CN101811190B - In-situ TiB2 and Ti5Si3 composite material and preparation method thereof - Google Patents

Abstract

The invention relates to an in-situ TiB2 and Ti5Si3 composite material and a preparation method thereof. The composite material comprises in-situ TiB2 and Ti5Si3, wherein the in-situ TiB2 is 1 to 20 percent based on the mass of TiB2. The preparation method comprises the following steps: 1) mixing B powder, Si powder and Ti powder, which serve as reactants, uniformly according to a certain proportion and pressing the reactants into billets; 2) preheating the reactant billets in an argon atmosphere and then heating the reactant billets again until a combustion synthesis reaction occurs, or igniting the bottom end of the reactant billets by using arc heat generated by a tungsten electrode to initiate the combustion synthesis reaction; and 3) after the reaction, pressurizing and compacting the reaction product to form the TiB2 and Ti5Si3 composite material. The material has the advantages of excellent performance such as high strength and high hardness, obvious reinforcement effect due to metallurgical combination between reinforcements and a matrix, convenient preparation process, simple equipment, low energy consumption and easy popularization and application.

Description

A kind of original position TiB＜sub〉2＜/sub 〉-Ti＜sub〉5＜/sub〉Si＜sub〉3＜/sub〉composite and preparation method thereof

Technical field

The present invention relates to field of compound material, particularly relate to a kind of original position TiB ₂-Ti ₅Si ₃Composite and preparation method thereof.

Background technology

Because compound Ti between refractory metal ₅Si ₃Have good high-temperature intensity and creep-resistant property, and excellent high-temperature oxidation resistance and decay resistance and enjoy favor.But, Ti ₅Si ₃Room temperature fragility big, fracture toughness is low, has limited its application.From the inherent attribute of material, compoundization is to solve Ti ₅Si ₃The effective way of fragility problem.In recent years, more about the research of compound composite material between bimetallic in the world, and adopt the research of Ceramic Composite intermetallic compound less relatively.The research paper that is published in " Materials Science and Engineering A, 1999,269:129-135 " shows that percent by volume is 20 ZrO ₂And Ti ₅Si ₃Compoundization improved the fracture toughness of material; In addition, the research paper that is published in " Journal of theEuropean Ceramic Society, 2002,22:551-558 " shows that percent by volume is 14～35 TiC and Ti ₅Si ₃Composite is increased to～4.2MPam from 3.0 with its fracture toughness of increase of in-situ ceramic mark ^1/2Ceramic particle TiB ₂Be suitable as very much Ti because of having high-melting-point, high rigidity, low-density and good excellent properties such as thermal conductivity ₅Si ₃The enhancing body.Regrettably, relevant TiB ₂Pottery strengthens Ti ₅Si ₃Research few.

Combustion synthesis reaction is that the fuel factor of utilizing reactant generation chemical reaction process to discharge is kept reaction voluntarily, thus synthetic new thing phase.Combustion synthesis reaction has that technology is easy, equipment is simple, energy consumption is low, aggregate velocity is exceedingly fast and advantage such as low pollutions, is widely used in high-temperature materials such as the ceramic and intermetallic compound of preparation.Because TiB ₂Pottery and Ti ₅Si ₃The forming process of intermetallic compound all belongs to high exothermic heat of reaction, and therefore, combustion synthesis technology is highly suitable for TiB ₂Pottery strengthens Ti ₅Si ₃The preparation of intermetallic compound composite material.

Summary of the invention

The purpose of this invention is to provide that a kind of technology is easy, equipment is simple, energy consumption is low, and the original position TiB that is easy to apply ₂-Ti ₅Si ₃Composite and preparation method thereof.

Technical scheme of the present invention is: under the protection of high-purity argon gas, the reactant pressed compact of a certain proportion of B powder, Si powder and Ti powder is placed on carries out combustion synthesis reaction in the combustion and synthesis device.After reaction finished, it is densified that the reactant pressed compact is pressurizeed, and prepares original position TiB ₂Pottery strengthens Ti ₅Si ₃Intermetallic compound composite material.Specific embodiment comprises that the preparation of reactant pressed compact and reaction form original position TiB ₂Pottery strengthens Ti ₅Si ₃Two stages of intermetallic compound composite material:

1) reactant pressed compact preparation:

A. the reactant pressed compact is formed: be made up of less than 44 microns B powder, Si powder and Ti powder powder particles, wherein the percentage by weight of B powder is 0.3≤B≤6.2, and the percentage by weight of Si powder is 20.8≤Si≤25.8, and all the other are the Ti powder;

B. batch mixing: take by weighing powder according to aforementioned proportion, and batch mixing 6 ± 1 hours in the ball mill of packing into, make it to mix;

C. compression moulding: the powder that mixes is put into mould, compression moulding at room temperature, and the pressed compact compact rate of molding is 70 ± 6%;

2) reaction forms original position TiB ₂-Ti ₅Si ₃Composite:

A. preheating: the reactant pressed compact is placed in the combustion and synthesis device, vacuumizes back 1 atmospheric high-purity argon gas of feeding and protect, with resistance wire the reactant pressed compact is heated to 450～600 degree and carries out preheating, and be incubated 20～25 minutes;

B. combustion synthesis reaction: continue to utilize resistance heat that the reactant pressed compact is heated, combustion synthesis reaction takes place until it; Perhaps the arc heat that produces with tungsten electrode in reactant pressed compact bottom is lighted, and causes combustion synthesis reaction;

C. densified: after combustion synthesis reaction finishes, the reactant pressed compact is applied the pressure of 15～30 MPas, and pressurize 5～20 minutes, make it densified, form original position TiB ₂Pottery strengthens Ti ₅Si ₃Intermetallic compound composite material.

The present invention compares with present existing technology has following characteristics:

The original position TiB that the invention provides a kind of simple and reliable process, saves the energy and be easy to apply ₂Pottery strengthens Ti ₅Si ₃Intermetallic compound composite material and preparation method thereof;

1) adopts B powder, Si powder and Ti powder as reactant system, form TiB by the chemical reaction original position ₂Pottery and Ti ₅Si ₃Intermetallic compound;

2) original position TiB ₂Pottery strengthens Ti ₅Si ₃TiB in the intermetallic compound composite material ₂And Ti ₅Si ₃Be metallurgical binding, the interface is clean, in conjunction with good.

3) the heat heating systems that utilizes reactant generation chemical reaction to discharge is saved the energy, the efficient height.

The specific embodiment

Embodiment one

(1) B powder, Si powder and the Ti powder of powder particles less than 44 microns taken by weighing in the ratio shown in the table 1, and batch mixing 6 ± 1 hours in the ball mill of packing into, make it to mix; Then powder is put into mould, at room temperature be pressed into base, the pressed compact compact rate of molding is 70 ± 6%;

(2) the reactant pressed compact is placed in the combustion and synthesis device, vacuumizes back 1 atmospheric high-purity argon gas of feeding and protect, with resistance wire the reactant pressed compact is heated to 450～600 degree and carries out preheating, and be incubated 20～25 minutes;

(3) continue to utilize resistance heat to the heating of reactant pressed compact, combustion synthesis reaction takes place until it;

(4) after combustion synthesis reaction finishes, the reactant pressed compact is applied the pressure of 15～30 MPas, and pressurize 5～20 minutes, make it densified, thereby form original position TiB ₂Pottery strengthens Ti ₅Si ₃Intermetallic compound composite material.Original position TiB ₂Pottery strengthens Ti ₅Si ₃Intermetallic compound composite material and Ti ₅Si ₃The intermetallic compound base body is compared, and hardness has improved 22～30%, and fracture toughness has improved 2～4 times.

Table 1 reactant preparation of powder ratio

Embodiment two

(1) B powder, Si powder and the Ti powder of powder particles less than 44 microns taken by weighing in the ratio shown in the table 2, and batch mixing 6 ± 1 hours in the ball mill of packing into, make it to mix; Then powder is put into mould, at room temperature be pressed into base, the pressed compact compact rate of molding is 70 ± 6%;

(2) the reactant pressed compact is placed in the combustion and synthesis device, vacuumizes back 1 atmospheric high-purity argon gas of feeding and protect, with resistance wire the reactant pressed compact is heated to 450～600 degree and carries out preheating, and be incubated 20～25 minutes;

(3) light with the arc heat that tungsten electrode produces reactant pressed compact bottom, causes combustion synthesis reaction;

(4) after combustion synthesis reaction finishes, the reactant pressed compact is applied the pressure of 15～30 MPas, and pressurize 5～20 minutes, make it densified, thereby form original position TiB ₂Pottery strengthens Ti ₅Si ₃Intermetallic compound composite material.

Table 2 reactant preparation of powder ratio

Claims (4)

1. original position TiB ₂-Ti ₅Si ₃Composite is characterized in that, TiB in the composite ₂The percentage by weight of pottery is 1≤TiB ₂≤ 20, all the other are Ti ₅Si ₃Intermetallic compound, and TiB ₂Pottery is to form Ti by Ti powder and B powder by the chemical reaction original position ₅Si ₃Intermetallic compound is to form TiB by chemical reaction by Ti powder and Si powder ₂And Ti ₅Si ₃Between be metallurgical binding.

2. a kind of original position TiB according to claim 1 ₂-Ti ₅Si ₃Composite is characterized in that described TiB ₂The best in quality percentage of ceramic particle is 3≤TiB ₂≤ 10.

3. a kind of original position TiB according to claim 1 ₂-Ti ₅Si ₃Composite is characterized in that, described TiB ₂Pottery is an in-situ particle, and it is of a size of submicron order, is shaped as hexa-prism.

4. one kind is used for the described a kind of original position TiB of claim 1 ₂-Ti ₅Si ₃The preparation method of composite is characterized in that, the preparation process of this composite may further comprise the steps:

1) reactant pressed compact preparation:

A. the reactant pressed compact is formed: be made up of less than 44 microns B powder, Si powder and Ti powder powder particles, wherein the percentage by weight of B powder is 0.3≤B≤6.2, and the percentage by weight of Si powder is 20.8≤Si≤25.8, and all the other are the Ti powder;

B. batch mixing: take by weighing powder according to aforementioned proportion, and batch mixing 6 ± 1 hours in the ball mill of packing into, make it to mix;

C. compression moulding: the powder that mixes is put into mould, compression moulding at room temperature, and the pressed compact compact rate of molding is 70 ± 6%;

2) reaction forms original position TiB ₂-Ti ₅Si ₃Composite:

A. preheating: the reactant pressed compact is placed in the combustion and synthesis device, vacuumizes back 1 atmospheric high-purity argon gas of feeding and protect, with resistance wire the reactant pressed compact is heated to 450～600 degree and carries out preheating, and be incubated 20～25 minutes;

B. combustion synthesis reaction: continue to utilize resistance heat that the reactant pressed compact is heated, combustion synthesis reaction takes place until it; Perhaps the arc heat that produces with tungsten electrode in reactant pressed compact bottom is lighted, and causes combustion synthesis reaction;

C. densified: after combustion synthesis reaction finishes, the reactant pressed compact is applied the pressure of 15～30 MPas, and pressurize 5～20 minutes, make it densified, form original position TiB ₂Pottery strengthens Ti ₅Si ₃Intermetallic compound composite material.