Gradient tungsten carbide knives is a composition gradient structure and tissue was graded distribution. Tungsten carbide composition gradient structure or organization through a gradient structure to achieve good performance, such as carbide can be given at the same time high hardness and high toughness. So as to solve the contradiction of traditional tungsten carbide hardness and toughness. Gradient tungsten carbide its overall performance was significantly higher than the average performance of conventional alloys.
In order to prevent as much as possible the material due to generation and propagation of cracks caused by the failure to obtain a high-performance tungsten carbide knives, typically prior to coating, a gradient of the sintered alloy substrate, sintered by the gradient of the coated substrate in which the surface region forming region lack toughness cubic tungsten carbides and carbonitrides, the binder content of the corresponding coated substrate is higher than the nominal content of binder, cracks formed in the coating when spread to the region, because of its good ductility and toughness, can absorb energy during crack propagation, it is possible to effectively prevent crack extended toward the inside of the alloy, improve the performance of cemented tungsten carbide knives. In tungsten carbide substrate and coating composition the same circumstances, the gradient tungsten carbide knives than those without fine gradient tungsten carbide knives.
Preparation of WC-Co gradient tungsten carbide knives mainly: first preparation less than normal carbon content of WC-Co alloy mix and compacted, and then at a certain temperature sintering, get tungsten carbide phase containing n (WC-Co system refers to the lack of carbon phase, such as Co3W3C2, Co2W4C, Co6W6C etc.). Followed by carburizing treatment, to obtain a gradient tungsten carbide, and further to prepare a gradient tungsten carbide knives.
FGM has been a breakthrough development in the field of high temperature materials, the energy, chemical, optical, electrical, biomedical and mechanical engineering sectors. Meanwhile, the gradient tungsten carbide knives have important applications in metal-cutting tools, wood cutting tools, mining oil drilling, composite materials processing tools.