 Cutting
Tool Materials
Cemented carbide (WC-Co) was developed in 1923 and was later
improved by adding TiC and TaC. In 1969, CVD coating technology
was developed, and coated carbide had been used widely.TiC-TiN
base cermet |
was developed in 1974. Today, "Coated Carbide
Grades for Roughing and Cermet for Finishing" is a well
established trend. |
| Characteristics of Hard Materials |
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| Hard Materials |
Hardness
(Hv) |
Energy Formation
(kcal/g·atom) |
Solubility in Iron
(%.1250°C) |
Thermal
Conductivity
(W/m¥·k) |
Thermal Expansion
(x10-6/k) |
Tool Materials |
| Diamond |
> 9,000 |
- |
Highly Soluble |
2,100 |
3,1 |
Sintered Diamond |
| CBN |
> 4,500 |
- |
- |
1,300 |
4,7 |
Sintered CBN |
| Si3N4 |
1,600 |
- |
- |
100 |
3,4 |
Ceramics |
| Al2O3 |
2,100 |
-100 |
=0 |
29 |
7,8 |
Ceramics Cemented Carbide |
| TiC |
3,200 |
-35 |
< 0.5 |
21 |
7,4 |
Ceramics
Coated Carbide
Cemented Carbide |
| TiN |
2,500 |
-50 |
- |
29 |
9,4 |
Cermet
Coated Carbide |
| TaC |
1,800 |
-40 |
0.5 |
21 |
6,3 |
Cemented Carbide |
| WC |
2,100 |
-10 |
7 |
121 |
5,2 |
Cemented Carbide |
| *1W/m·K=2.39x10-3cal/cm·sec·°C |
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