JPH0398766A - Manufacture of metal bonded tool - Google Patents
Manufacture of metal bonded toolInfo
- Publication number
- JPH0398766A JPH0398766A JP23299689A JP23299689A JPH0398766A JP H0398766 A JPH0398766 A JP H0398766A JP 23299689 A JP23299689 A JP 23299689A JP 23299689 A JP23299689 A JP 23299689A JP H0398766 A JPH0398766 A JP H0398766A
- Authority
- JP
- Japan
- Prior art keywords
- alloy powder
- abrasive grains
- iron
- carbon
- solid solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 29
- 239000002184 metal Substances 0.000 title claims abstract description 29
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 109
- 239000006061 abrasive grain Substances 0.000 claims abstract description 88
- 239000000956 alloy Substances 0.000 claims abstract description 81
- 239000000843 powder Substances 0.000 claims abstract description 77
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 73
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 63
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 61
- 229910052742 iron Inorganic materials 0.000 claims abstract description 54
- 238000001816 cooling Methods 0.000 claims abstract description 43
- 239000006104 solid solution Substances 0.000 claims abstract description 33
- 239000000203 mixture Substances 0.000 claims abstract description 16
- 238000010438 heat treatment Methods 0.000 claims abstract description 12
- 239000002994 raw material Substances 0.000 claims abstract description 8
- 239000002245 particle Substances 0.000 claims description 45
- 229910003460 diamond Inorganic materials 0.000 claims description 33
- 239000010432 diamond Substances 0.000 claims description 33
- 238000000034 method Methods 0.000 claims description 24
- 238000005245 sintering Methods 0.000 claims description 21
- 229910052582 BN Inorganic materials 0.000 claims description 2
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims 1
- 230000008018 melting Effects 0.000 claims 1
- 239000011159 matrix material Substances 0.000 abstract description 38
- 238000000227 grinding Methods 0.000 description 43
- 230000000052 comparative effect Effects 0.000 description 20
- 239000002244 precipitate Substances 0.000 description 19
- 239000000463 material Substances 0.000 description 18
- 230000007423 decrease Effects 0.000 description 12
- 229910052710 silicon Inorganic materials 0.000 description 12
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 11
- 239000010703 silicon Substances 0.000 description 11
- 230000014759 maintenance of location Effects 0.000 description 8
- 239000000314 lubricant Substances 0.000 description 7
- 238000005498 polishing Methods 0.000 description 6
- 238000005507 spraying Methods 0.000 description 6
- 238000009792 diffusion process Methods 0.000 description 5
- 238000005266 casting Methods 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000010298 pulverizing process Methods 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910001567 cementite Inorganic materials 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000007731 hot pressing Methods 0.000 description 2
- 238000010406 interfacial reaction Methods 0.000 description 2
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 2
- 238000005461 lubrication Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 238000007517 polishing process Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910000997 High-speed steel Inorganic materials 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000009766 low-temperature sintering Methods 0.000 description 1
- 229910001105 martensitic stainless steel Inorganic materials 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- QMQXDJATSGGYDR-UHFFFAOYSA-N methylidyneiron Chemical compound [C].[Fe] QMQXDJATSGGYDR-UHFFFAOYSA-N 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000001272 pressureless sintering Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Polishing Bodies And Polishing Tools (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の目的〕
（産業上の利用分野）
本発明は炭素を含有する鉄基合金と、高硬度を有する砥
粒との焼結体から成る砥粒層を有するメタルボンド工具
の製造方法に係り、特に材料中に微小な炭素を均一に分
散させることが可能であり、研削時における潤滑性を高
めるとともに、マトリックスの強度を改善し、寿命の増
大を図ったメタルボンド工具の製造方法に関する。[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a metal having an abrasive grain layer consisting of a sintered body of an iron-based alloy containing carbon and abrasive grains having high hardness. Regarding the manufacturing method of bond tools, in particular, it is possible to uniformly disperse microscopic carbon in the material, which improves lubricity during grinding, improves matrix strength, and extends life. It relates to a method for manufacturing tools.
（従来の技術）
酸化アルミニウム、窒化ケイ素、窒化アルミニウム、炭
化ケイ素などの高硬度ファインセラミックスの研削加工
、仕上加工に使用される研削工具として、砥粒にダイヤ
モンドを使用したメタルボンドダイヤモンド工具が、従
来より広く用いられている。(Conventional technology) Metal-bonded diamond tools that use diamond as abrasive grains are conventionally used as grinding tools for grinding and finishing high-hardness fine ceramics such as aluminum oxide, silicon nitride, aluminum nitride, and silicon carbide. more widely used.
またバナジウム（Ｖ）を含む高速度鋼やマルテンサイト
系ステンレス鋼などの難削合金材の研削加工や仕上加工
においては、砥粒として立方品窒化硼素（以下ｒＣＢＮ
Ｊと略称する。）をマトリックス中に分散させたメタル
ボンド窒化硼素工具が使用されている。In addition, cubic boron nitride (hereinafter referred to as rCBN) is used as an abrasive grain for grinding and finishing of difficult-to-cut alloy materials such as high-speed steel and martensitic stainless steel containing vanadium (V).
It is abbreviated as J. ) dispersed in a matrix have been used.
上記のようなメタルボンド工具のうち、例えば砥粒にダ
イヤモンド粉末を用いるメタルボンドダイヤモンド工具
は、一般に金属粉末および必要により金属化合物を含む
金属粉末とダイヤモンド粉末砥粒とを混合した後に焼結
して形成される。この焼結操作によってマトリックスと
ダイヤモンド粉末砥粒との結合力、機械的強度の向上が
図られ、形成されたメタルボンドダイヤモンド工具は、
適宜ドレッシングによって砥石表面を再生しながら研磨
・研削用工具として使用されている。Among the above-mentioned metal bond tools, for example, metal bond diamond tools that use diamond powder as abrasive grains are generally made by mixing diamond powder abrasive grains with metal powder and metal powder containing a metal compound if necessary, and then sintering the abrasive grains. It is formed. This sintering operation improves the bonding force and mechanical strength between the matrix and the diamond powder abrasive grains, and the resulting metal bonded diamond tool is
It is used as a polishing and grinding tool while regenerating the surface of the whetstone by dressing it appropriately.
ところで、切込み深さが大きい重研削加工に適したメタ
ルボンドダイヤモンド工具の場合、マトリックスの原料
としては、炭素含有量が大きな鉄基合金鋳造材の切粉を
、ボールミルまたはスタンプ法などで粉砕した粉末が使
用される。この高炭素鉄基合金粉末にダイヤモンド砥粒
を均一・に混合し、真空またはアルゴンなどの不活性ガ
スによる保護雰囲気において例えば温度８００〜９００
’Ｃ、圧力２００〜４ＱＱｋｇ／ｃｎｆ程度の条件で、
ホットプレスを行ない、砥粒層を形成している。砥粒の
周囲には炭素粒子が分散するように固定される。By the way, in the case of metal-bonded diamond tools that are suitable for heavy-duty grinding with large depths of cut, the raw material for the matrix is powder obtained by pulverizing chips of iron-based alloy casting material with a high carbon content using a ball mill or stamping method. is used. Diamond abrasive grains are uniformly mixed with this high carbon iron-based alloy powder, and the mixture is heated to a temperature of 800 to 900, for example, in a vacuum or in a protected atmosphere with an inert gas such as argon.
'C, under conditions of pressure 200~4QQkg/cnf,
Hot pressing is performed to form an abrasive layer. Carbon particles are fixed and dispersed around the abrasive grains.
この炭素粒子は研削対象物との研削抵抗を低減する潤滑
材として働く一方、マトリックスはダイヤモンド砥粒を
支持固定する保持材として機能する。The carbon particles act as a lubricant that reduces grinding resistance with the object to be ground, while the matrix acts as a holding material that supports and fixes the diamond abrasive grains.
（発明が解決しようとする課題）
しかしながら、従来の製造方法で合金鋳造材の切粉を粉
砕して得られた鉄基合金粉末は、鋳造時の冷却速度が小
さいため炭素の析出物の大きさが数十μｍないし数百μ
ｍと砥粒の平均粒径（数十μｍ〜１００μｍ）に比較し
て大きく、また形状的にも不均一であり、微細に分散し
た組織になっていない。(Problems to be Solved by the Invention) However, iron-based alloy powder obtained by crushing chips of alloy casting materials using conventional manufacturing methods has a low cooling rate during casting, so the size of carbon precipitates is small. is several tens of μm to several hundred μm
It is larger than the average particle size of the abrasive grains (several tens of μm to 100 μm), and is non-uniform in shape, and does not have a finely dispersed structure.
そのため粉砕操作によって粉末中に保持されていた炭素
粒子の脱落が起り易く、粉末中の炭素の分布および形状
が不均一になる。そしてこの鉄基合金粉末によりマトリ
ックスを形成した工具材料では、炭素析出物の径が大き
いことから、研削中に炭素析出物が脱落し易く、また脱
落によって形威された窪みに削り屑や磨き屑が堆積して
目詰りの原因となり、さらに目詰りは焼き付きによるマ
トリックスの破損や塑性変形を生起する。Therefore, the carbon particles held in the powder are likely to fall off during the crushing operation, resulting in uneven distribution and shape of carbon in the powder. In tool materials whose matrix is formed from iron-based alloy powder, the diameter of carbon precipitates is large, so carbon precipitates tend to fall off during grinding, and shavings and polishing debris can form in the depressions created by falling off. is deposited and causes clogging, which further causes damage to the matrix due to seizure and plastic deformation.
また砥粒の近傍に窪みが形威されることによって砥粒の
保持強度が急減し、ダイヤモンド砥粒の脱落が急増して
研削、研磨効率の低下を招き、さらに高い仕上げ精度が
得られないという問題があった。In addition, due to the formation of depressions near the abrasive grains, the retention strength of the abrasive grains rapidly decreases, and the diamond abrasive grains rapidly fall off, leading to a decrease in grinding and polishing efficiency, making it impossible to obtain higher finishing accuracy. There was a problem.
また従来のメタルボンドダイヤモンド工具の製造工程に
おいては、グラフアイトなどの炭素粉末を添加して圧縮
成形後、焼結操作を行なうことによって焼結体中に炭素
粒を分散させる方法を採用しているが、砥粒層全体に微
小な炭素粒を均一に分散させることが困難であった。そ
のため炭素析出物および砥粒の脱落が多く、これにより
研削・研磨加工の効率が低下し、高い仕上げ精度が得ら
れない上に砥石自体の寿命が短いという根本的な問題点
があった。In addition, in the conventional manufacturing process for metal-bonded diamond tools, carbon particles such as graphite are added, compression molded, and then sintered to disperse carbon particles in the sintered body. However, it has been difficult to uniformly disperse fine carbon grains throughout the abrasive grain layer. As a result, many carbon precipitates and abrasive grains fall off, which reduces the efficiency of grinding and polishing processes, making it impossible to obtain high finishing accuracy, and posing the fundamental problem that the life of the grinding wheel itself is short.
本発明は上記の問題点を解決するためになされたもので
あり、材料中に微小な炭素粒子を均一に分散させ、研削
時における潤滑性を高めるとともに、マトリックスの強
度を高め砥粒および潤滑材としての炭素粒の脱落が少な
く、高い効率で研削・研磨加工を実施することが可能で
あり、寿命が長い経済的なメタルボンド工具を製造し得
るメタルボンド工具の製造方法を提供することを目的と
する。The present invention was made to solve the above-mentioned problems, and by uniformly dispersing fine carbon particles in the material, it improves lubricity during grinding, increases the strength of the matrix, and improves the abrasive grains and lubricant. The purpose of the present invention is to provide a method for manufacturing a metal bond tool that can produce an economical metal bond tool that has a long lifespan, has less carbon particles falling off, and can perform grinding and polishing processes with high efficiency. shall be.
（課題を解決するための手段と作用）
本願発明者等は、従来の問題点がマトリックス中の炭素
の形態に起因することを見い出し、研削時における炭素
による潤滑作用を保持しつつ、寿命の長いメタルボンド
工具を得ることを目的にして、マトリックス材料中に微
細な炭素粒子を分散させる方法を研究し、さらに砥粒層
の研磨特性に及ぼす合金粉末の粒径、砥石の種類および
粒径の影響を研究した。(Means and effects for solving the problem) The inventors of the present application discovered that the conventional problem was caused by the form of carbon in the matrix. With the aim of obtaining metal-bonded tools, we investigated the method of dispersing fine carbon particles in the matrix material, and also investigated the effects of the particle size of the alloy powder, type of grinding wheel, and particle size on the polishing properties of the abrasive layer. researched.
その結果、原料となる鉄基合金粉末を、その固溶温度以
上に加熱して固溶体を形或し、得られた固溶体を毎秒５
℃以上の冷却速度で２００℃以下の温度まで冷却し、し
かる後に得られた鉄基合金粉末と砥粒との混合物を一体
に焼結して砥粒層を形成したときに、従来と比較して、
研削特性が格段に優れた長寿命のメタルボンド工具を得
ることができた。As a result, the raw material iron-based alloy powder is heated above its solid solution temperature to form a solid solution, and the resulting solid solution is
When the mixture of iron-based alloy powder and abrasive grains obtained after cooling to a temperature of 200°C or less at a cooling rate of 100°C or more is sintered to form an abrasive grain layer, compared to the conventional method, hand,
We were able to obtain a long-life metal bond tool with significantly superior grinding properties.
またマトリックスとなる鉄基合金粉末の焼結前の平均粒
径を砥粒の平均粒径の１／３以下に設定したときに、強
固なマトリックスが形成され、砥粒および炭素粒の脱落
が効果的に抑制され、寿命の長い砥粒層を得ることがで
きた。Furthermore, when the average particle size of the iron-based alloy powder that forms the matrix before sintering is set to 1/3 or less of the average particle size of the abrasive grains, a strong matrix is formed and the shedding of the abrasive grains and carbon grains is effectively prevented. It was possible to obtain an abrasive grain layer with a long life and a long service life.
本発明は上記知見に基づいてさなれたものである。本発
明方法において使用する鉄基合金粉末としては、Ｆｅを
基材として他に潤滑剤となる炭素や炭素の析出を促進さ
せる硅素や焼結性を改善するためのＮｉ，Ｇｏなどの元
素を添加した合金材が使用される。また合金材の組成は
、必要とされるマトリックスの強度、伝熱性等を勘案し
て決定されるが、一般に砥粒の保持強度を高めるために
、２種以上の金属を複合化させた合金材が使用される。The present invention has been made based on the above findings. The iron-based alloy powder used in the method of the present invention is made of Fe as a base material, with addition of carbon to serve as a lubricant, silicon to promote carbon precipitation, and elements such as Ni and Go to improve sinterability. The alloy material is used. The composition of the alloy material is determined by taking into consideration the required strength of the matrix, heat conductivity, etc., but in general, alloy materials are made by combining two or more metals in order to increase the retention strength of the abrasive grains. is used.
合金材を粉末化する手段としては、例えば合金材の鋳塊
片をボールミル、スタンプミルによって粉砕する方法や
合金材を溶湯噴霧法等の通常の急冷法を使用して微細化
する方法がある。Examples of means for pulverizing the alloy material include a method of pulverizing an ingot of the alloy material using a ball mill or a stamp mill, and a method of pulverizing the alloy material using a normal rapid cooling method such as a molten metal spraying method.
上記溶湯噴霧法は、原料合金材の溶湯を、ガス噴霧、水
噴霧、遠心噴霧等によって粉体化する方法であり、噴霧
条件により適当な冷却速度と粉末粒径になるように調整
して、所望の原料粉末を得る方法である。The above-mentioned molten metal spraying method is a method in which the molten metal of the raw material alloy material is pulverized by gas spraying, water spraying, centrifugal spraying, etc., and the cooling rate and powder particle size are adjusted to be appropriate according to the spraying conditions. This is a method for obtaining desired raw material powder.
本発明方法においては、所定の組成および粒径に調製さ
れた鉄基合金粉末を、その固溶温度以上に加熱して固溶
体を形成し、得られた固溶体を、毎秒５℃以上の冷却速
度で２００℃以下の温度まで急速に冷却する。In the method of the present invention, iron-based alloy powder prepared to have a predetermined composition and particle size is heated to a temperature higher than its solid solution temperature to form a solid solution, and the resulting solid solution is cooled at a cooling rate of 5°C per second or higher. Cool rapidly to a temperature below 200°C.
固溶温度以上に加熱することにより、合金粉末に含有さ
れる炭素は一旦全て鉄基質中に固溶し、均質な固溶体を
形成する。この固溶体を冷却すると冷却速度に応じた粒
径を有する炭素が基質中に析出する。By heating above the solid solution temperature, all of the carbon contained in the alloy powder is once dissolved in the iron matrix to form a homogeneous solid solution. When this solid solution is cooled, carbon having a particle size depending on the cooling rate is precipitated into the matrix.
この冷却速度が毎秒５℃未満の緩速冷却であると炭素の
析出物が粗大化し、工具として使用した場合に潤滑剤と
しての機能が低下する一方、砥粒の脱落が頻発し研削研
磨効率の低下を招き、また高い仕上げ精度が得られない
。If the cooling rate is slower than 5°C per second, the carbon precipitates will become coarser and the function as a lubricant will decrease when used as a tool, while abrasive grains will frequently fall off and reduce grinding and polishing efficiency. In addition, high finishing accuracy cannot be obtained.
一方、毎秒５℃以上で急速に冷却すると、析出物の粗大
化が阻止され炭素の微小な析出物が合金粉末内に均一に
分散されるため、砥粒の保持強度の低下もなく、研削比
が極めて大きく寿命の長い工具を形成することができる
。On the other hand, rapid cooling at 5°C or more per second prevents the coarsening of precipitates and disperses fine carbon precipitates uniformly within the alloy powder, so there is no decrease in the retention strength of the abrasive grains and the grinding ratio is It is possible to form a tool with an extremely large size and a long life.
また冷却処理において、合金粉末は、２００℃以下の温
度まで充分冷却することが必要である。Further, in the cooling treatment, the alloy powder needs to be sufficiently cooled to a temperature of 200° C. or lower.
２００℃を超える温度まで冷却された高温状態において
は、まだ粉末内の元素の拡散移動が活発であり、炭素析
出物の粗大化が進行してしまうからである。This is because, in a high temperature state where the powder is cooled to a temperature exceeding 200° C., diffusion and movement of elements within the powder is still active, and coarsening of carbon precipitates progresses.
さらに調製する合金粉末の平均粒径は１５０μｍ以下で
、かつ砥粒の平均粒径の１／３以下のものが好ましい。Further, the average particle size of the alloy powder to be prepared is preferably 150 μm or less and 1/3 or less of the average particle size of the abrasive grains.
平均粒径が１５０μｍを超え、また砥粒の平均粒径の１
／３を超える場合は、マトリックス中の砥粒の分布が不
均一となり、砥粒の保持強度も低下し、工具としての研
削研磨能力が低下する傾向があるからである。The average particle size exceeds 150 μm, and the average particle size of the abrasive grains exceeds 150 μm.
This is because if it exceeds /3, the distribution of abrasive grains in the matrix becomes non-uniform, the retention strength of the abrasive grains also decreases, and the grinding and polishing ability of the tool tends to decrease.
また、マトリックスを形成する鉄基合金粉末中の炭素は
１．５重量％以上、好ましくは２．５重量％以上、４．
５重量％以下に調整される。これは炭素量が１．５％未
満では自己潤滑性の低下を招き、またマトリックス金属
としての強度が低下し、さらに砥粒であるダイヤモンド
が鉄基材中に溶出してしまうからである。Further, the carbon content in the iron-based alloy powder forming the matrix is 1.5% by weight or more, preferably 2.5% by weight or more; 4.
The content is adjusted to 5% by weight or less. This is because if the carbon content is less than 1.5%, self-lubricating properties will be reduced, the strength as a matrix metal will be reduced, and diamond, which is an abrasive grain, will be eluted into the iron base material.
一方、炭素含有量が４．５重量％を超えると、マトリッ
クスが脆化し工具としての強度が低下するため、炭素含
有量は１．５〜４．５重量％の範囲に定められる。On the other hand, if the carbon content exceeds 4.5% by weight, the matrix becomes brittle and the strength as a tool decreases, so the carbon content is set in the range of 1.5 to 4.5% by weight.
このように本発明において用いる鉄基合金としては、前
述した範囲の炭素を含有するものであればよく、加熱冷
却工程において、冷却速度を所定値以上に設定し、この
炭素の析出物の大きさを制御することにより本発明の効
果が得られるのであって、通常の工具のマトリックスに
用いられるような鉄基合金であれば、Ｍｎ，Ｍｇ等の不
可避的不純物を含んでいても良く、その組成は問われな
い。As described above, the iron-based alloy used in the present invention may contain carbon in the range described above, and in the heating and cooling process, the cooling rate is set to a predetermined value or higher, and the size of the carbon precipitates is reduced. The effects of the present invention can be obtained by controlling is not asked.
しかしながらこの合金組成として硅素を添加すると、硅
素が基質のセメンタイトを不安定にして炭素（黒鉛）を
生し易くさせて、より細かい炭素析出物が形成され、マ
トリックスの強度および潤滑性を高めることができる。However, when silicon is added to this alloy composition, silicon destabilizes the cementite matrix, making it easier to generate carbon (graphite), forming finer carbon precipitates, and increasing the strength and lubricity of the matrix. can.
この硅素量は１． Ｏｗｌ％〜３． ５ｗｔ％が好
ましい。硅素量が１．０％未満では、炭素の析出および
粒径が不均一となると同時に、工具としての十分な強度
が得にくい。一方、硅素量が３．５％を超えると、マト
リックス金属の主な部分を占めるフエライト相が変態、
硬化することにより焼結性が低下し強度が小さくなり易
いからである。This amount of silicon is 1. Owl%~3. 5 wt% is preferred. If the amount of silicon is less than 1.0%, carbon precipitation and grain size become non-uniform, and at the same time, it is difficult to obtain sufficient strength as a tool. On the other hand, when the amount of silicon exceeds 3.5%, the ferrite phase that occupies the main part of the matrix metal undergoes transformation.
This is because hardening tends to reduce sinterability and strength.
また砥粒としては、ダイヤモンド粉末の他にＣＢＮを混
合して使用することもできる。ダイヤモンドおよびＣＢ
Ｎのヌープ硬さはそれぞれ、８５０ ０． ５ １
０ ０ｋｇ／７以上といずれも極めて高い値を有し、難
研削材の加工用砥粒として有用である。特にＣＢＮ砥粒
は、耐熱性に優れているため、冷却材を使用しない乾式
加工用砥粒として急速に用途を拡大している。Further, as the abrasive grains, CBN may be mixed in addition to diamond powder. diamond and cb
The Knoop hardness of N is 850 0. 5 1
All have extremely high values of 0.0 kg/7 or more, and are useful as abrasive grains for processing difficult-to-grind materials. In particular, CBN abrasive grains have excellent heat resistance, so their use as abrasive grains for dry machining without using a coolant is rapidly expanding.
前記のように、微小な炭素を均一に析出させた鉄基合金
粉末と、砥粒として用いるダイヤモンドおよび／または
ＣＢＮとを均一に混合した混合物を一体に焼結して砥粒
層が形成され、その砥粒層と合金部とを接合してメタル
ボンド工具が製造される。As described above, an abrasive grain layer is formed by sintering a mixture of an iron-based alloy powder in which fine carbon is uniformly precipitated, and diamond and/or CBN used as abrasive grains, and A metal bond tool is manufactured by joining the abrasive grain layer and the alloy part.
焼結操作は非酸化性雰囲気中で１０００〜１１８０℃程
度で実施すると良い。焼結温度が１０００℃未満ではＦ
ｅ中にＳｉ，Ｃを拡散させるために長時間を要し、十分
な強度を有する砥粒層が得にくい。一方１１８０℃を超
えると液相を生じ、砥粒との界面反応を生じ、砥粒層の
強度低下を招き易い。The sintering operation is preferably carried out at about 1000 to 1180°C in a non-oxidizing atmosphere. F when the sintering temperature is less than 1000℃
It takes a long time to diffuse Si and C in e, making it difficult to obtain an abrasive grain layer with sufficient strength. On the other hand, if the temperature exceeds 1180°C, a liquid phase is generated, which causes an interfacial reaction with the abrasive grains, which tends to cause a decrease in the strength of the abrasive grain layer.
加圧焼結を用いると、上記常圧焼結と比較して、８５０
℃以上での低温焼結が可能となり、界面反応が起こりに
くい。さらに焼結体の寸法変化が少なく、ツルーイング
を簡素化できる。When pressure sintering is used, compared to the above-mentioned pressureless sintering, 850
Low-temperature sintering at temperatures above ℃ is possible, and interfacial reactions are less likely to occur. Furthermore, dimensional changes in the sintered body are small, and truing can be simplified.
加圧力は、成形性および焼結時の相互拡散を促進させる
ために５０ｋｇ／ｃｍ以上に設定される。しかし加圧焼
結を行なう場合においても、焼結温度が８５０℃未満で
は鉄基材中に硅素、炭素を拡散させるために長時間を要
し、十分な強度が得にくい。したがって加圧焼結温度は
８５０〜１１８０℃の範囲に設定される。The pressing force is set to 50 kg/cm or more in order to promote formability and mutual diffusion during sintering. However, even when pressure sintering is performed, if the sintering temperature is lower than 850°C, it takes a long time to diffuse silicon and carbon into the iron base material, making it difficult to obtain sufficient strength. Therefore, the pressure sintering temperature is set in the range of 850 to 1180°C.
このように本発明に係るメタルボンド工具の製造方法に
よれば、マトリックスを形威する鉄基合金粉末を、その
固溶温度以上に一旦加熱して固溶体を形成し、得られた
固溶体を毎秒５℃以上の冷却速度で急速に冷却して鉄基
合金粉末を調製している。そのため合金粉末内には微小
な炭素の析出物を均一に分散させることができる。した
がってマトリックスによる砥粒の保持強度の低下がなく
、潤滑性も十分に保持することが可能となり、工具の寿
命を著しく延伸することができる。As described above, according to the method for manufacturing a metal bond tool according to the present invention, the iron-based alloy powder forming the matrix is once heated to a temperature higher than its solid solution temperature to form a solid solution, and the obtained solid solution is Iron-based alloy powder is prepared by rapid cooling at a cooling rate of ℃ or higher. Therefore, fine carbon precipitates can be uniformly dispersed within the alloy powder. Therefore, there is no reduction in the retention strength of the abrasive grains by the matrix, and it is possible to maintain sufficient lubricity, and the life of the tool can be significantly extended.
また急速冷却後における合金粉末の温度は２００°Ｃ以
下に設定されているため、冷却後における合金構成元素
の拡散は少なく、炭素の析出物の粗大化を防止すること
ができる。Further, since the temperature of the alloy powder after rapid cooling is set to 200° C. or less, the diffusion of alloy constituent elements after cooling is small, and coarsening of carbon precipitates can be prevented.
さらにセメンタイトを不安定にして黒鉛の析出物を生じ
易くする硅素を添加することにより、合金粉末中に、よ
り安定した微細な炭素析出物を均一に形成することが可
能となり、ボンド材の強度および砥粒との界面結合力を
向上させることができる。Furthermore, by adding silicon, which destabilizes cementite and facilitates the formation of graphite precipitates, it becomes possible to uniformly form more stable and fine carbon precipitates in the alloy powder, improving the strength of the bond material. The interfacial bonding force with the abrasive grains can be improved.
また、マトリックスを形成する金属粉末と、ダイヤモン
ドおよびＣＢＮの少なくとも一方から成る高硬度の砥粒
とを焼結によって強固に結合して砥粒層を形成している
ため、砥粒の保持力が大きく、良好な研削仕上面が得ら
れるとともに工具の寿命を延伸することができる。なお
砥粒としてダイヤモンドおよびＣＢＮを併用することに
より研削対象範囲を広くすることができる。In addition, the metal powder that forms the matrix and the highly hard abrasive grains made of at least one of diamond and CBN are firmly bonded by sintering to form the abrasive grain layer, so the retention force of the abrasive grains is large. , it is possible to obtain a good ground surface and extend the life of the tool. Note that by using diamond and CBN together as abrasive grains, the range to be ground can be widened.
またマトリックスを形成する鉄基合金粉末の内部に予め
微細な炭素析出物が均一に分散されるため、焼結後にお
いても、潤滑材としての炭素粒を、砥粒の周辺に均一に
分散配置することができる。In addition, since fine carbon precipitates are uniformly dispersed in advance inside the iron-based alloy powder that forms the matrix, even after sintering, the carbon grains as a lubricant are uniformly distributed around the abrasive grains. be able to.
また鉄基合金粉末の平均粒径を、砥粒の平均粒径に対し
て１／３以下に調整しているため、潤滑材としての炭素
粒および砥粒の支持材となる鉄基合金粉末を、砥粒の周
辺に均一に分散させることができる。In addition, the average particle size of the iron-based alloy powder is adjusted to 1/3 or less of the average particle size of the abrasive grains. , it can be uniformly dispersed around the abrasive grains.
したがって、研削加工時の潤滑機能が充分に発揮される
とともに、支持材としてのマトリックスの強度が充分確
保され、砥粒の脱落が抑制される結果、常に高い研削効
率を維持できる上に砥粒層の寿命を大幅に延伸させるこ
とができる。Therefore, the lubrication function during grinding is fully demonstrated, the strength of the matrix as a supporting material is ensured sufficiently, and abrasive grains are prevented from falling off. As a result, it is possible to maintain high grinding efficiency at all times, and the abrasive grain layer The lifespan of can be significantly extended.
（実施例）
次に本発明について以下に示す実施例を参照して、より
具体的に説明する。(Examples) Next, the present invention will be described in more detail with reference to the following examples.
実施例１〜３および比較例４〜６
まず実施例１〜３として、炭素３．０％、硅素１．５％
、残部鉄から成り、平均粒径が３０μｍである鉄基合金
粉末を通常のスタンプミル法によって調製した。Examples 1 to 3 and Comparative Examples 4 to 6 First, as Examples 1 to 3, carbon 3.0% and silicon 1.5%
An iron-based alloy powder consisting of , balance iron and having an average particle size of 30 μm was prepared by a conventional stamp mill method.
次に鉄基合金粉末を、固溶温度以上である１１８０℃ま
で加熱し、炭素、硅素等の添加元素を鉄基質中に完全に
固溶せしめた固溶体を形成した。Next, the iron-based alloy powder was heated to 1180° C., which is higher than the solid solution temperature, to form a solid solution in which additional elements such as carbon and silicon were completely dissolved in the iron matrix.
次に固溶体を形成した鉄基合金粉末に冷却用の圧縮空気
を作用させて、冷却速度がそれぞれ毎秒５，１．０．２
０℃となるように調整し、温度が２００℃になるまで冷
却した。Next, compressed air for cooling is applied to the iron-based alloy powder that has formed a solid solution, and the cooling rate is 5 and 1.0.2 per second, respectively.
The temperature was adjusted to 0°C, and the temperature was cooled to 200°C.
ここで冷却速度の調節は、通常の冷却操作と同様に合金
粉末層に送給する冷却用圧縮空気の温度および流量を制
御して行なった。Here, the cooling rate was adjusted by controlling the temperature and flow rate of the cooling compressed air fed to the alloy powder layer, as in a normal cooling operation.
次に上記加熱処理および冷却処理によって得られた鉄基
合金粉末８０重量％に対して平均粒径１００μｍのダイ
ヤモンド砥粒を２０重量％を均一に混合した。さらに上
記組成の混合物を外径８０ｍｍ，内径１５ｍｍの金型空
間に充填し、真空中でホットプレス法により焼結を行な
った。焼結操作は、４ ０ ０ ｋｇ／ｃａｆの加圧力
を作用させた状態で９００℃に昇温し、３０分間保持し
た後に加工を施し、幅１０ｍｍのダイヤモンド工具を形
或した。Next, 20% by weight of diamond abrasive grains having an average particle size of 100 μm were uniformly mixed with 80% by weight of the iron-based alloy powder obtained by the above heat treatment and cooling treatment. Furthermore, the mixture having the above composition was filled into a mold space having an outer diameter of 80 mm and an inner diameter of 15 mm, and sintering was performed by hot pressing in a vacuum. In the sintering operation, the temperature was raised to 900° C. while applying a pressure of 400 kg/caf, held for 30 minutes, and then processed to form a diamond tool with a width of 10 mm.
また比較例４， ５． ６として実施例１〜３と同
一の合金組成を有する原料を使用し、同一温度まで加熱
した後に、冷却速度をそれぞれ１℃／ｓｅｃ．３℃／ｓ
ｅｃに設定し温度２００℃まで急冷したもの（比較例４
．５）および冷却速度１０℃／ｓｅｅで温度３００℃ま
で急冷したもの（比較例６）をダイヤモンド砥粒と混合
して焼結後、加工して外径８０ｌＩＩＩＩ＋１内径１５
關、幅１０ｍｍのダイヤモンド工具とした。Also, Comparative Examples 4 and 5. 6, raw materials having the same alloy composition as those in Examples 1 to 3 were used, and after heating to the same temperature, the cooling rate was 1° C./sec. 3℃/s
EC and rapidly cooled to a temperature of 200°C (Comparative Example 4)
．． 5) and the one rapidly cooled to a temperature of 300°C at a cooling rate of 10°C/see (Comparative Example 6) was mixed with diamond abrasive grains, sintered, and processed to obtain an outer diameter of 80 lIII + 1 inner diameter of 15
A diamond tool with a width of 10 mm was used.
こうして得られた実施例１〜３および比較例４〜６のダ
イヤモンド工具を使用してビッカース硬度１７００のＳ
ｉ３Ｎ４の研削加工を行なった。Using the thus obtained diamond tools of Examples 1 to 3 and Comparative Examples 4 to 6, S with a Vickers hardness of 1700 was used.
Grinding of i3N4 was performed.
研削加工条件は、回転数３０００ｒｐｍ，送り速度５ｍ
／ｍｉｎ，研削幅１０ｍｍ，切込み深さは、０．２５ｍ
ｍに設定した。Grinding conditions are rotation speed 3000 rpm, feed speed 5 m.
/min, grinding width 10mm, cutting depth 0.25m
It was set to m.
こうして得られた研削試験結果を第１表の実施例１〜３
、比較例４〜６に対応する右欄に示す。The grinding test results obtained in this way are shown in Examples 1 to 3 in Table 1.
, shown in the right column corresponding to Comparative Examples 4 to 6.
ここで第１表に示す研削面粗さとは、被加工材であるＳ
ｉａＮ４の表面粗さの測定値を示し、また研削比は、砥
石損耗量に対する被研削材の除去量の比で表わしている
。Here, the ground surface roughness shown in Table 1 refers to the S
The measured value of the surface roughness of iaN4 is shown, and the grinding ratio is expressed as the ratio of the amount of material to be ground removed to the amount of wear on the grinding wheel.
第１表の結果からわかるように冷却処理において、冷却
速度を５℃／ｓｅｃ以上に設定して調製された鉄基合金
粉末中の析出炭素の平均粒径は極めて微細であり、この
合金粉末を使用した実施例１−〜３のダイヤモンド砥石
は、冷却速度を５°Ｃ ／ ｓ ｅＣ未満で処理した比
較例４，５と比べて研削比がいずれも高く、長寿命を有
することがわかる。As can be seen from the results in Table 1, the average particle size of the precipitated carbon in the iron-based alloy powder prepared by setting the cooling rate to 5°C/sec or more in the cooling process is extremely fine; It can be seen that the diamond grindstones used in Examples 1 to 3 have higher grinding ratios and longer life than Comparative Examples 4 and 5, which were processed at a cooling rate of less than 5°C/sec.
一方比較例４，５に示す合金粉末は、冷却速度が緩速で
あるため、炭素析出物の粗大化が進み、平均粒径が大き
くなる。そのため、研削時における研削面粗さが大きく
なり、研削比も低下する傾向が観察される。On the other hand, since the alloy powders shown in Comparative Examples 4 and 5 have a slow cooling rate, the carbon precipitates become coarser and the average particle size becomes larger. Therefore, a tendency is observed that the roughness of the ground surface increases during grinding and the grinding ratio also decreases.
また比較例６に示すように、冷却速度を１０゜Ｃ／ｓｅ
ｃと大きく設定しても、冷却後の温度を３００℃と高値
にした場合、粉末内部における元素の拡散が冷却後にお
いても進行し、析出炭素の平均粒径が粗大化し、研削特
性がやや低下することがわかる。In addition, as shown in Comparative Example 6, the cooling rate was set to 10°C/se.
Even if it is set to a large value c, if the temperature after cooling is set to a high value of 300℃, the diffusion of elements inside the powder will proceed even after cooling, the average particle size of the precipitated carbon will become coarser, and the grinding characteristics will deteriorate slightly. I understand that.
実施例７〜９および比較例１０〜１２
次に実施例７〜９として、第１表に示す組戊を有し、鋳
造法によって得た鉄基合金をスタンプミルによって粉砕
して得た鉄基合金粉末を、その固溶温度以上の温度１１
６０〜１２００℃に加熱して固溶体を形成し、次に得ら
れた固溶体を毎秒１０℃の冷却速度で、温度１８０℃ま
で急冷した。Examples 7 to 9 and Comparative Examples 10 to 12 Next, as Examples 7 to 9, iron-based alloys having the structures shown in Table 1 and obtained by crushing iron-based alloys obtained by a casting method with a stamp mill were used. The alloy powder is heated to a temperature higher than its solid solution temperature 11
A solid solution was formed by heating to 60-1200°C, and then the resulting solid solution was rapidly cooled to a temperature of 180°C at a cooling rate of 10°C per second.
この加熱冷却処理によって、微細の析出炭素が均一に分
散した平均粒径が３０μｍの鉄基合金粉末を得た。Through this heating and cooling treatment, an iron-based alloy powder having an average particle size of 30 μm in which fine precipitated carbon was uniformly dispersed was obtained.
次に得られた鉄基合金粉末８０重量％に対して平均粒径
１００μｍのＣＢＮを２０重量％の割合で加え、均一に
混合した混合物を前記実施例１〜３と同様な焼結加工条
件で焼結し、外径８０肺、内径１５閣、幅１０ｍｍのＣ
ＢＮ砥石を形成した。Next, 20% by weight of CBN with an average particle size of 100 μm was added to 80% by weight of the obtained iron-based alloy powder, and the uniformly mixed mixture was sintered under the same conditions as in Examples 1 to 3. Sintered, C with an outer diameter of 80 mm, an inner diameter of 15 mm, and a width of 10 mm.
A BN grindstone was formed.
また比較例１０〜ｔ２として、実施例７，８，９と同一
の組成を有する鉄基合金粉末を、その固溶温度より低い
温度（８００〜９００℃）に加熱した後に、実施例７〜
９と同様の条件で冷却し、さらにＣＢＮ砥粒と混合、焼
結して同一形状のＣＢＮ砥石を形威した。Further, as Comparative Example 10-t2, iron-based alloy powder having the same composition as Examples 7, 8, and 9 was heated to a temperature lower than its solid solution temperature (800 to 900°C), and then
It was cooled under the same conditions as in No. 9, and further mixed with CBN abrasive grains and sintered to form a CBN grindstone of the same shape.
そして上記実施例７〜．９および比較例１０〜１２によ
って得られたＣＢＮ砥石を使用して、実施例１〜３と同
様な加工条件で超硬合金の研削加工を実施して研削比を
測定し、加熱温度の高低が研削特性に及ぼす影響を調査
した。研削試験結果は第１表の対応する右欄に示す。And the above-mentioned Examples 7-. Using the CBN grinding wheels obtained in Comparative Examples 10 to 12, grinding of cemented carbide was performed under the same processing conditions as in Examples 1 to 3, and the grinding ratio was measured. The influence on the grinding properties was investigated. The grinding test results are shown in the corresponding right column of Table 1.
第１表の結果から理解されるように、ＣＢＮ砥粒を使用
した場合においても、合金粉末を一旦、その固溶温度よ
り高温度に加熱した後に急冷した鉄基合金粉末を使用し
た実施例７〜９の方が、固溶温度以下で加熱した比較例
１０〜１２よりも研削比が優れている。比較例ｌＯ〜１
２においては、加熱温度が固溶温度以下であるため、炭
素の固溶が少なく、高速度で冷却しても合金粉末中の析
出炭素を微細化することが困難である。そのため工具の
マトリックスの強度が低下するため、研削比が低下する
傾向が伺える。As can be understood from the results in Table 1, even when using CBN abrasive grains, Example 7 used an iron-based alloy powder that was heated to a temperature higher than its solid solution temperature and then rapidly cooled. -9 have better grinding ratios than Comparative Examples 10-12, which were heated below the solid solution temperature. Comparative example lO~1
In No. 2, since the heating temperature is below the solid solution temperature, there is little carbon dissolved in the solid solution, and it is difficult to make the precipitated carbon in the alloy powder fine even if it is cooled at a high rate. As a result, the strength of the tool matrix decreases, which suggests a tendency for the grinding ratio to decrease.
実施例１３．１４および比較例１５〜１８次に実施例１
３．１４は、炭素３．０％、硅素１．０％、残部鉄から
成る鋳造材の鉄基合金をスタンプミル法によって粉砕し
、平均粒径をそれぞれ１０．１５μｍに調整した鉄基合
金粉末とした。次に得られた鉄基合金粉末を、その固溶
温度より高い１１５０℃に加熱し、さらに冷却速度２０
℃／ｓｅｃで１５０℃まで急速冷却した。Examples 13.14 and Comparative Examples 15-18 Next, Example 1
3.14 is an iron-based alloy powder obtained by crushing a cast iron-based alloy consisting of 3.0% carbon, 1.0% silicon, and the balance iron using a stamp mill method, and adjusting the average particle size to 10.15 μm. And so. Next, the obtained iron-based alloy powder was heated to 1150°C, which is higher than its solid solution temperature, and the cooling rate was further increased to 20°C.
It was rapidly cooled to 150°C at a rate of °C/sec.
こうして得られた鉄基合金粉末７５重量％に対して、砥
粒としてダイヤモンド砥粒（平均粒径５５μｍ）および
ＣＢＮ砥粒（平均粒径５５μｍ）を重量比で９：１の割
合、すなわちそれぞれ２２．５重量％、２．５重量％ず
つ混合し、得られた混合粉末を実施例１〜３と同様な焼
結加工を施して、ダイヤモンドＣＢＮ複合砥石を形成し
たものである。Diamond abrasive grains (average particle size 55 μm) and CBN abrasive grains (average particle size 55 μm) were used as abrasive grains at a weight ratio of 9:1, that is, 22% by weight of each of the thus obtained iron-based alloy powders. .5% by weight and 2.5% by weight were mixed, and the obtained mixed powder was subjected to the same sintering process as in Examples 1 to 3 to form a diamond CBN composite grindstone.
また比較例１５〜１７として、実施例１３〜１４で得た
鉄基合金と同様の組成を有する鋳造材をスタンプ法によ
って粉砕し、平均粒径を２５〜９０μｍの範囲で変え、
砥粒の平均粒径（５５μｍ）に対する粒径比を０．４５
〜１．６４まで変化させて、さらに実施例１３〜１４と
同様な焼結体組成、焼結条件でダイヤモンドＣＢＮ複合
砥石を形成した。In addition, as Comparative Examples 15 to 17, cast materials having the same composition as the iron-based alloys obtained in Examples 13 to 14 were crushed by a stamping method, and the average particle size was varied in the range of 25 to 90 μm.
The particle size ratio to the average particle size (55 μm) of the abrasive grains is 0.45.
~1.64, and a diamond CBN composite grindstone was further formed using the same sintered body composition and sintering conditions as in Examples 13-14.
また比較例１８として、実施例１３〜１４で得られた鋳
造材の鉄基合金をスタンプ法にて粉砕し、平均粒径６０
μｍの鉄基合金粉末を調製し、加熱冷却処理を施さずに
、砥粒と混合し、実施例１３〜１４と同様な焼結体組成
・焼結条件で焼結後、加工してダイヤモンドＣＢＮ複合
砥石を形成した。In addition, as Comparative Example 18, the iron-based alloy of the cast material obtained in Examples 13 to 14 was pulverized by a stamping method, and the average particle size was 60.
μm iron-based alloy powder was prepared, mixed with abrasive grains without heating and cooling treatment, sintered with the same sintered body composition and sintering conditions as in Examples 13 and 14, and then processed to produce diamond CBN. A composite grindstone was formed.
実施例１３〜１４および比較例１５〜１８で得られたダ
イヤモンドＣＢＮ複合砥石を使用して、実施例１〜３と
同様な加工条件でＳｉ３Ｎ４の研削加工試験を実施した
ところ下記第１表の右欄に示す結果を得た。Using the diamond CBN composite grindstones obtained in Examples 13 to 14 and Comparative Examples 15 to 18, a grinding test of Si3N4 was conducted under the same processing conditions as in Examples 1 to 3. The results shown in the column were obtained.
第１表の結果からわかるようにダイヤモンド砥粒とＣＢ
Ｎ砥粒との混合砥粒を使用し、合金粉末の粒径を砥粒の
平均粒径の１／３以下に設定した実施例１３．１４にお
いては、良好な加工仕上げを行なうことが可能であり、
また高い研削比を確保することができる。As can be seen from the results in Table 1, diamond abrasive grains and CB
In Examples 13 and 14, in which mixed abrasive grains with N abrasive grains were used and the grain size of the alloy powder was set to 1/3 or less of the average grain size of the abrasive grains, it was possible to perform good machining and finishing. can be,
Furthermore, a high grinding ratio can be ensured.
しかし、比較例１５〜１７で示すように、マトリックス
となる金属粉末の平均粒径が砥粒の平均粒径の１／３を
超える場合は、砥粒の脱落が増加し、研削比が逆に低下
する。したがってマトリックスを構成する金属粉末の平
均粒径は砥粒の平均粒径の１／３以下に設定することが
必要である。However, as shown in Comparative Examples 15 to 17, when the average particle size of the metal powder serving as the matrix exceeds 1/3 of the average particle size of the abrasive grains, the shedding of the abrasive grains increases and the grinding ratio is reversed. descend. Therefore, it is necessary to set the average particle size of the metal powder constituting the matrix to 1/3 or less of the average particle size of the abrasive grains.
一方、比較例１８で示すように従来法に従って鋳造材を
粉砕して調製された鉄基合金粉末を加熱冷却せずに、そ
のまま焼結体の原料とした場合は、合金粉末中の析出炭
素の粒径が大きいため、マトリックスの強度が低下し、
充分な研削特性が得られないことがわかる。On the other hand, as shown in Comparative Example 18, when the iron-based alloy powder prepared by crushing the cast material according to the conventional method is used as the raw material for the sintered body without heating and cooling, the precipitated carbon in the alloy powder is Due to the large particle size, the strength of the matrix decreases,
It can be seen that sufficient grinding characteristics cannot be obtained.
以上説明の通り本発明に係るメタルポンドエ具の製造方
法によれば、マトリックスを形成する鉄基合金粉末を、
その固溶温度以上に一旦加熱して固溶体を形成し、得ら
れた固溶体を毎秒５℃以上の冷却速度で急速に冷却して
鉄基合金粉末を調製している。そのため合金粉末内には
微小な炭素の析出物を均一に分散させることができる。As explained above, according to the method for manufacturing a metal punching tool according to the present invention, the iron-based alloy powder forming the matrix is
An iron-based alloy powder is prepared by once heating above the solid solution temperature to form a solid solution, and then rapidly cooling the obtained solid solution at a cooling rate of 5° C. per second or more. Therefore, fine carbon precipitates can be uniformly dispersed within the alloy powder.
したがってマトリックスによる砥粒の保持強度の低下が
なく、潤滑性も十分に保持することが可能となり、工具
の寿命を著しく延伸することができる。Therefore, there is no reduction in the retention strength of the abrasive grains by the matrix, and it is possible to maintain sufficient lubricity, and the life of the tool can be significantly extended.
また急速冷却後における合金粉末の温度は２００℃以下
に設定されているため、冷却後における合金構成元素の
拡散は少なく、炭素の析出物の粗大化を防止することが
できる。Further, since the temperature of the alloy powder after rapid cooling is set to 200° C. or lower, diffusion of alloy constituent elements after cooling is small, and coarsening of carbon precipitates can be prevented.
また、鉄基合金粉末の平均粒径を砥粒の平均粒径に対し
て１／３以下に調整しているため、潤滑材としての炭素
粒および砥粒の支持材となる鉄基合金粉末を砥粒の周辺
に均一に分散することができる。In addition, since the average particle size of the iron-based alloy powder is adjusted to 1/3 or less of the average particle size of the abrasive grains, the iron-based alloy powder that serves as the support material for the carbon grains as a lubricant and the abrasive grains can be reduced. It can be uniformly dispersed around the abrasive grains.
また、マトリックスを形成する金属粉末と、ダイヤモン
ドおよびＣＢＮの少なくとも一方から成る高硬度の砥粒
とを焼結によって強固に結合して砥粒層を形威している
ため、砥粒の保持力が大きく、良好な研削仕上面が得ら
れるとともに工具の寿命を延伸することができる。なお
砥粒としてダイヤモンドおよびＣＢＮを併用することに
より研削対象範囲を広くすることができる。In addition, the metal powder that forms the matrix and high-hardness abrasive grains made of at least one of diamond and CBN are firmly bonded by sintering to form an abrasive grain layer, which increases the retention force of the abrasive grains. A large and good ground surface can be obtained, and the life of the tool can be extended. Note that by using diamond and CBN together as abrasive grains, the range to be ground can be widened.
またマトリックスを形成する鉄基合金粉末中に予め微細
な炭素析出物が均一に分散されるため、焼結後において
も、潤滑材としての炭素粒を、砥粒の周辺に均一に分散
配置することができる。In addition, since fine carbon precipitates are uniformly dispersed in advance in the iron-based alloy powder that forms the matrix, even after sintering, the carbon grains as a lubricant can be uniformly distributed around the abrasive grains. I can do it.
したがって、研削加工時の潤滑機能が充分に発揮される
とともに、支持材としてのマトリックスの強度が充分確
保され、砥粒の脱落が抑制される結果、常に高い研削効
率を維持できる上に砥粒層の寿命を大幅に延伸させるこ
とができる。Therefore, the lubrication function during grinding is fully demonstrated, the strength of the matrix as a supporting material is ensured sufficiently, and abrasive grains are prevented from falling off. As a result, it is possible to maintain high grinding efficiency at all times, and the abrasive grain layer The lifespan of can be significantly extended.
Claims (1)
成る砥粒層を備えたメタルボンド工具の製造方法におい
て、原料となる鉄基合金粉末を、固溶温度以上に加熱し
て固溶体を形成し、得られた固溶体を毎秒５℃以上の冷
却速度で２００℃以下の温度まで冷却し、得られた鉄基
合金粉末と砥粒との混合物を一体に焼結して砥粒層を形
成することを特徴とするメタルボンド工具の製造方法。 ２、鉄基合金粉末の平均粒径は砥粒の平均粒径の１／３
以下に設定した請求項１記載のメタルボンド工具の製造
方法。 ３、砥粒としてダイヤモンドおよび立方晶窒化硼素の少
なくとも一種を用いることを特徴とする請求項１記載の
メタルボンド工具の製造方法。[Scope of Claims] 1. In a method for manufacturing a metal bond tool having an abrasive grain layer made of a sintered body of carbon-containing iron-based alloy powder and abrasive grains, iron-based alloy powder as a raw material is hardened. A solid solution is formed by heating above the melting temperature, the obtained solid solution is cooled to a temperature of 200°C or less at a cooling rate of 5°C or more per second, and the obtained mixture of iron-based alloy powder and abrasive grains is integrated. A method for manufacturing a metal bond tool, characterized by forming an abrasive layer by sintering. 2. The average particle size of the iron-based alloy powder is 1/3 of the average particle size of the abrasive grains.
A method for manufacturing a metal bond tool according to claim 1, set as follows. 3. The method for manufacturing a metal bond tool according to claim 1, wherein at least one of diamond and cubic boron nitride is used as the abrasive grain.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23299689A JPH0398766A (en) | 1989-09-11 | 1989-09-11 | Manufacture of metal bonded tool |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23299689A JPH0398766A (en) | 1989-09-11 | 1989-09-11 | Manufacture of metal bonded tool |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0398766A true JPH0398766A (en) | 1991-04-24 |
Family
ID=16948169
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23299689A Pending JPH0398766A (en) | 1989-09-11 | 1989-09-11 | Manufacture of metal bonded tool |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0398766A (en) |
-
1989
- 1989-09-11 JP JP23299689A patent/JPH0398766A/en active Pending
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