JP2775810B2 - Cemented carbide with composite area - Google Patents
Cemented carbide with composite areaInfo
- Publication number
- JP2775810B2 JP2775810B2 JP1032347A JP3234789A JP2775810B2 JP 2775810 B2 JP2775810 B2 JP 2775810B2 JP 1032347 A JP1032347 A JP 1032347A JP 3234789 A JP3234789 A JP 3234789A JP 2775810 B2 JP2775810 B2 JP 2775810B2
- Authority
- JP
- Japan
- Prior art keywords
- alloy
- cemented carbide
- binder phase
- region
- amount
- 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.)
- Expired - Fee Related
Links
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、優れた靭性と耐摩耗性とを兼ね備えた超硬
合金に関する。Description: TECHNICAL FIELD The present invention relates to a cemented carbide having both excellent toughness and wear resistance.
従来から、工具用合金として、WCやTiC等を含む硬質
分散相と、Fe、Ni、Co等の鉄族金属の結合相とからなる
超硬合金が用いられてきた。特に、ポンチ、ヘツダー等
の鍛造工具のように耐摩耗性及び耐衝撃性が要求される
ものには、WC−Co系超硬合金が主に使用されている。Conventionally, as a tool alloy, a cemented carbide composed of a hard dispersed phase containing WC, TiC and the like and a binder phase of an iron group metal such as Fe, Ni and Co has been used. In particular, WC-Co cemented carbides are mainly used for those requiring wear resistance and impact resistance, such as forging tools such as punches and headers.
これら超硬合金では、工具としての性能を改善するた
め、Co量の調整やWCの微細化によつて耐摩耗性や靭性の
向上が図られてきた。In these cemented carbides, wear resistance and toughness have been improved by adjusting the amount of Co and miniaturizing WC in order to improve the performance as a tool.
しかし、耐摩耗性と靭性とは相反する性質であるた
め、両方を同時に改善向上させることは困難であつた。
例えば、WC−Co系超硬合金では、高靭性を付与するため
Co量を増加させると必然的に耐摩耗性が低下し、逆にCo
量を減少させると耐摩耗性は向上するが靭性が低下す
る。However, since the wear resistance and the toughness are contradictory properties, it has been difficult to improve and improve both at the same time.
For example, in the case of WC-Co cemented carbide,
Increasing the amount of Co inevitably lowers the wear resistance.
When the amount is reduced, the wear resistance is improved, but the toughness is reduced.
このような事情から、超硬合金の耐摩耗・耐衝撃用工
具としての用途は、ハイスに比較して制限されてきた。Under these circumstances, the use of cemented carbide as a tool for wear and impact resistance has been limited as compared with high-speed steel.
〔発明が解決しようとする課題〕 本発明はかかる従来の事情に鑑み、耐摩耗・耐衝撃用
工具としては好適な、優れた靭性と耐摩耗性とを兼ね具
えた超硬合金を提供することを目的とする。[Problems to be Solved by the Invention] In view of such conventional circumstances, the present invention provides a cemented carbide having both excellent toughness and wear resistance, which is suitable as a tool for wear and impact resistance. With the goal.
上記目的を達成するために、本発明ではWCを含む硬質
分散相を鉄族金属の結合相とからなる超硬合金におい
て、プレス成形の型に所定の結合相量の粉末を充填し、
その表面となる部分に結合相量を減少させた粉末を充填
し、これをプレス成形した後焼結することにより、合金
表面に合金内部よりも結合相量の減少した領域を形成
し、合金表面部に0.5〜33kg/mm2の圧縮応力を生ぜしめ
たことを特徴とする。In order to achieve the above object, in the present invention, in a cemented carbide comprising a hard dispersed phase containing WC and a binder phase of an iron group metal, a powder of a predetermined amount of a binder phase is filled in a press mold,
The surface portion is filled with a powder having a reduced amount of the binder phase, pressed, and then sintered to form a region on the alloy surface where the amount of the binder phase is smaller than that of the inside of the alloy. It is characterized in that a compressive stress of 0.5 to 33 kg / mm 2 is generated in the part.
本発明の超硬合金では、合金表面にCo等の結合相量を
減少した領域を有するので、合金表面での耐摩耗性が繊
維又は改善される。これと同時に、耐摩耗性に寄与しな
い合金内部で相対的にCo等の結合相量を多く出来るの
で、全体として高い靭性を付与することが可能である。Since the cemented carbide of the present invention has a region in which the amount of the binder phase such as Co is reduced on the surface of the alloy, the wear resistance on the surface of the alloy is improved or improved. At the same time, the amount of the binder phase such as Co can be relatively increased inside the alloy that does not contribute to the wear resistance, so that high toughness as a whole can be provided.
結合相量減少領域の厚さtdと、該領域以外の平均的結
合相量領域の厚さtsとの比ts/tdは1.0〜100の範囲が好
ましい。The ratio ts / td between the thickness td of the binder phase reduction region and the thickness ts of the average binder phase region other than the region is preferably in the range of 1.0 to 100.
超硬合金の表面と内部に２つの組成の異なる領域が形
成されるので、焼結後の冷却過程において合金表面部に
引張力ないし圧縮力の残留応力が生じる。即ち、合金表
面部の残留応力σは、結合相量減少領域の厚さtd、熱膨
張係数αｄ及びヤング率Edと、その他の平均結合相量領
域の厚さts、熱膨張係数αｓ及びヤング率Esとにより、
次式で表わされる： σ＝Ｋ（αｓ−αｄ）Ed・△Ｔ （Ｋはts/td及びEs/Edで定められる値であり、△Ｔは焼
結温度と室温の温度差を表わす。） 従つて、結合相量減少領域と平均的結合量領域の組成
や厚さ等を選択することによつて、合金表面部に圧縮応
力を生ぜしめることが可能である。例えば、WC−Co系超
硬合金では上記の比ts/tdがほぼ1.0〜100の範囲におい
て、残留応力σが圧縮応力となる。具体的に、合金表面
をWC−10wt％Co及び合金内部をWC−15wt％Coで構成した
本発明の超硬合金について、合金表面部の残留応力σと
両領域の厚さの比ts/tdの関係を図面に示す。このよう
に、合金表面部に圧縮応力を与えることにより、圧縮応
力のない同一組成の合金表面部よりも引張強度や破壊靭
性値を一層向上させることが出来る。Since two regions having different compositions are formed on the surface and inside of the cemented carbide, residual stress such as tensile or compressive force is generated on the surface of the alloy during the cooling process after sintering. That is, the residual stress σ of the alloy surface portion is determined by the thickness td of the reduced binder phase region, the thermal expansion coefficient αd, and the Young's modulus Ed, and the thickness ts of the other average binder phase region, the thermal expansion coefficient αs, and the Young's modulus. With Es,
Σ = K (αs−αd) Ed · ΔT (K is a value determined by ts / td and Es / Ed, and ΔT represents a temperature difference between the sintering temperature and room temperature.) Therefore, it is possible to generate a compressive stress on the surface of the alloy by selecting the composition, thickness and the like of the region for reducing the amount of the binder phase and the region for the average amount of the bond. For example, in a WC-Co cemented carbide, the residual stress σ becomes the compressive stress when the above ratio ts / td is in the range of approximately 1.0 to 100. Specifically, for the cemented carbide of the present invention in which the alloy surface is composed of WC-10wt% Co and the inside of the alloy is WC-15wt% Co, the ratio ts / td between the residual stress σ of the alloy surface and the thickness of both regions. Is shown in the drawing. As described above, by applying a compressive stress to the alloy surface portion, the tensile strength and the fracture toughness value can be further improved as compared with an alloy surface portion having the same composition without the compressive stress.
実施例１ 型を用いて外径20mm及び内径10mmの円筒状にプレス成
形したWC−15wt％Coの粉末の外周に、更にWC−7wt％Co
粉末を厚さ0.1mm、0.5mm、1mmとなるようにプレス成形
して複層構造とし、1400℃で焼結した。得られた合金の
合金表面（外周）の結合相量減少領域の厚さtdと、該領
域以外の平均的結合相量領域の厚さtsとの比ts/tdは、
試料Ａ、Ｂ及びＣが夫々50、10及び１であつた。又、合
金表面部の残留応力をＸ線解析で測定したところ、試料
Ａ、Ｂ及びＣが夫々−10kg/mm2、−24kg/mm2及び−0.5k
g/mm2であつた。Example 1 A WC-15wt% Co powder pressed into a cylindrical shape having an outer diameter of 20mm and an inner diameter of 10mm using a mold was further coated with WC-7wt% Co.
The powder was press-molded to a thickness of 0.1 mm, 0.5 mm, and 1 mm to form a multilayer structure, and sintered at 1400 ° C. The ratio ts / td of the thickness td of the reduced binder phase region on the alloy surface (outer periphery) of the obtained alloy to the thickness ts of the average binder phase region other than the region is:
Samples A, B and C were 50, 10 and 1, respectively. When the residual stress on the alloy surface was measured by X-ray analysis, samples A, B, and C showed -10 kg / mm 2 , -24 kg / mm 2, and -0.5 k, respectively.
g / mm 2 .
各合金試料を前方押出用ポンチとして用い、SCR21を
断面減少率58％及び押出長10mmで寿命テストを行なつ
た。比較のために、通常のWC−7Swt％Coの合金（試料
Ｄ）とWC−15wt％Co合金（試料Ｅ）からなるポンチにつ
いても同様にテストした。その結果、本発明の合金であ
る試料Ａ、Ｂ及びＣでは夫々12万個、30万個及び８万個
のシヨツトが可能であつた。しかし、試料Ｄは６万個で
亀裂が発生して寿命に至り、試料Ｅは４万個で摩耗が大
きく使用不能となつた。Each alloy sample was used as a punch for forward extrusion, and a life test was performed using SCR21 with a reduction in area of 58% and an extrusion length of 10 mm. For comparison, a punch made of a conventional WC-7Swt% Co alloy (Sample D) and a WC-15wt% Co alloy (Sample E) were similarly tested. As a result, 120,000, 300,000 and 80,000 shots were possible for Samples A, B and C, which are the alloys of the present invention, respectively. However, in Sample D, cracks occurred in 60,000 pieces and the life was reached, and in Sample E, in 40,000 pieces, wear was so large that the sample could not be used.
実施例２ 実施例１と同じ試料Ａ、Ｂ及びＣを用いて、初期形状
が直径32mm及び長さ／径1.5のS15Cを鍛造（前方押出）
してキヤブランクを加工した。この時のポンチの寿命は
試料Ａ、Ｂ乃びＣが夫々８万個、30万個及び６万個であ
つた。Example 2 Using the same samples A, B and C as in Example 1, forging S15C having an initial shape of 32 mm in diameter and a length / diameter of 1.5 (forward extrusion).
The blank was then processed. The life of the punches at this time was 80,000, 300,000 and 60,000 for samples A, B and C, respectively.
しかし、比較のために行なつた通常のWC−7wt％Co合
金（試料Ｄ）とWC−15wt％Co合金（試料Ｅ）での同様の
テストでは、試料Ｄは２万個で亀裂が発生して寿命に至
り、試料Ｅは3000個で摩耗が大きく使用不能となつた。However, in a similar test using a normal WC-7wt% Co alloy (sample D) and a WC-15wt% Co alloy (sample E) performed for comparison, cracks occurred in 20,000 samples D. As a result, the life of the sample E was increased to 3,000 samples, and the sample E was worn out and became unusable.
本発明によれば、合金表面と内部とで結合相量を変え
た領域を形成することによつて、優れた靭性と耐摩耗性
とを兼ね具えた超硬合金を提供することが出来る。According to the present invention, it is possible to provide a cemented carbide having both excellent toughness and wear resistance by forming a region in which the amount of the binder phase is changed between the surface and the inside of the alloy.
従って、この超硬合金は、鍛造等に用いる耐摩耗・耐
衝撃用工具として好適である。Therefore, this cemented carbide is suitable as a wear and impact resistant tool used for forging and the like.
図面は本発明の超硬合金の一具体例において、合金表面
部の残留応力σと、合金表面の結合相量減少領域の厚さ
tdと該領域以外の平均的結合相量領域の厚さtsとの比ts
/tdとの関係を示すグラフである。The drawing shows, in one embodiment of the cemented carbide according to the present invention, the residual stress σ at the alloy surface and the thickness of the region where the amount of bonded phase is reduced on the alloy surface.
The ratio ts between td and the thickness ts of the average binder phase region other than the region.
6 is a graph showing a relationship with / td.
Claims (1)
からなる超硬合金において、プレス成形の型に所定の結
合相量の粉末を充填し、その表面となる部分に結合相量
を減少させた粉末を充填し、これをプレス成形した後焼
結することにより、合金表面に合金内部よりも結合相量
の減少した領域を形成し、合金表面部に0.5〜33kg/mm2
の圧縮応力を生ぜしめたことを特徴とする超硬合金。In a cemented carbide comprising a hard dispersed phase containing WC and a binder phase of an iron group metal, a press-molding mold is filled with a predetermined amount of powder of a binder phase, and a surface of the binder is filled with a binder phase. By filling the powder with reduced amount, press forming and sintering it, a region where the amount of the binder phase is reduced than the inside of the alloy is formed on the surface of the alloy, and 0.5 to 33 kg / mm 2 is formed on the surface of the alloy.
A cemented carbide characterized by having a high compressive stress.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1032347A JP2775810B2 (en) | 1989-02-10 | 1989-02-10 | Cemented carbide with composite area |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1032347A JP2775810B2 (en) | 1989-02-10 | 1989-02-10 | Cemented carbide with composite area |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02209448A JPH02209448A (en) | 1990-08-20 |
| JP2775810B2 true JP2775810B2 (en) | 1998-07-16 |
Family
ID=12356425
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1032347A Expired - Fee Related JP2775810B2 (en) | 1989-02-10 | 1989-02-10 | Cemented carbide with composite area |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2775810B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69310568T2 (en) * | 1992-02-20 | 1998-01-22 | Mitsubishi Materials Corp | Carbide alloy |
| JP3691289B2 (en) * | 1999-06-10 | 2005-09-07 | 本田技研工業株式会社 | Composite mold |
| JP3691290B2 (en) * | 1999-06-10 | 2005-09-07 | 本田技研工業株式会社 | Composite coating material |
| JP3691306B2 (en) * | 1999-09-24 | 2005-09-07 | 本田技研工業株式会社 | Composite mold |
| JP2004292905A (en) | 2003-03-27 | 2004-10-21 | Tungaloy Corp | Compositionally graded sintered alloy and method of producing the same |
| GB0816836D0 (en) | 2008-09-15 | 2008-10-22 | Element Six Holding Gmbh | Steel wear part with hard facing |
| US20120177453A1 (en) | 2009-02-27 | 2012-07-12 | Igor Yuri Konyashin | Hard-metal body |
| JP6889128B2 (en) * | 2018-03-20 | 2021-06-18 | 京セラ株式会社 | Tools and cutting tools equipped with them |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0182759B2 (en) * | 1984-11-13 | 1993-12-15 | Santrade Ltd. | Cemented carbide body used preferably for rock drilling and mineral cutting |
-
1989
- 1989-02-10 JP JP1032347A patent/JP2775810B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02209448A (en) | 1990-08-20 |
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