Ti-Ta-W-based cemented carbides for cutting tool applications
Description
Ti-Ta-W-based cemented carbides (TTC) for multi-purpose cutting insert applications are sintered three-phase materials based on carbides of W, Ti and Ta embedded in Co binder, typically processed by powder metallurgy route. Metallic binder content typically varies from 6 wt% to 11 wt%. Unlike conventional two-phase WC-based hard metals, TTC materials contain nearly spherical grains of solid solution Ti-Ta-W phase, WC grains, and Co-rich phase which is basically a solid solution of three carbides in cobalt.
TTC cemented carbides have high hardness, superior hot strength, good oxidation and abrasion resistance, and improved hot hardness. They also have high toughness, wear-resistance and very good cutting edge strength when used as cutting tools.
Applications
Structural steel
Low-alloyed steel
Stainless steel
Grey, malleable, high-strength cast iron grades
Parameter | Material | |||
VHS55 | VHS60 | VHS65 | VHS58 | |
Chemical analysis, wt% | WC–74, TiC-15, TaC-5, Co-6 | - | WC–74, TiC-8, TaC-7, Co-11 | - |
Density,g/cm³ | 13.1 | 12.5 | 13.3 | 13.2 |
Microstructure, micron
| 1 - 2 | 1 - 2 | 1 - 2 | 1 - 2 |
Coercitivity, Oe | 145 - 175 | 120 - 170 | 145 - 175 | - |
Transverse rupture strength, MPa | 2000 | 1500 | 2300 | 1520 |
Rockwell hardness, HRA | 91.5 | 91.0 | 90.0 | 91.3 |
Impact toughness, kJ mˆ(-2) | 18 - 20 | - | 20 - 25 | - |
Fracture toughness, MPa m½ | - | 8.0 - 9.0 | - | 8.0 - 10.0 |