Nanocrystalline cemented carbide is a tool material developed in recent years. It is based on nano tungsten carbide powder.
The cemented carbide with high hardness, high wear resistance and high toughness has been produced under the condition of adding proper binder and grain growth inhibitor, its performance is obviously higher than that of conventional cemented carbide. It has been widely used in hard metal materials, cutting tools, micro drills in the electronics industry, precision molds, medical fields and other fields.
In the aspect of ultrafine or nanocrystalline cemented carbide, there are only a few countries in the world such as the United States, Japan, Sweden and so on, which can produce alloy with both high hardness (HRA>90) and high strength (>3 200 MPa). The main difficulties come from ultrafine and nano tungsten carbide powder and other raw materials and cemented carbide production process.
From 70 to 80s in China began to study the industrial production of submicron and ultrafine WC cemented carbide, the granulated tungsten oxide reduction method and the self reduction tungstate process have been developed; Since the beginning of 90s, ultrafine tungsten carbide powder has been produced by hydrogen plasma reduction, micro - violet tungsten reduction, fluidized bed gas phase reduction carbonization, high frequency plasma method, WC-15Co tungsten cobalt carbide alloy with hardness HRA>90 and strength >3 200 MPa was prepared. But compared with the advanced level in the world, there are still some gaps in product quality, production capacity, cost, production process and continuity.
Tungsten cobalt alloy is also called WC Co cemented carbide. According to cobalt content, can be divided into high cobalt (20%~30%), cobalt (10%~15%) and low cobalt (3%~8%) three categories. The key of tungsten cobalt alloy is the purity of tungsten carbide powder. Although some achievements have been made in the research and production of nano tungsten carbide powder, there is still a big gap compared with the advanced level in the world.
It is proposed to strengthen the research on the basic theory, according to China's actual situation, we should boldly study and adopt new technology and process, it is necessary to study the production process of nanometer tungsten carbide powder which is suitable for the situation of our country and has the world's leading level.