Characteristics and application ways of precision parts processing cemented carbide

Hard alloy is a tool material made by powder metallurgy process, it is some refractory tungsten carbide (WC), titanium carbide (TiC) compound powder and binder cobalt (Co) mixed, through pressure forming, sintering and made. It is characterized by high hardness (69~81HRC) and thermal hardness (up to 900~1000℃), good wear resistance and high compressive strength, it can be processed by high speed steel tool can not process the material, can be doubled to improve the cutting speed of precision parts processing, extend the life of the tool. Because of the high hardness and brittleness of hard alloy, it is generally developed into a certain specification of the blade, insert welding is used on the knife body.

Commonly used hard alloys are tungsten-cobalt and tungsten-titanium cobalt two categories:

 1. Tungsten and cobalt cemented carbides:

The brand of tungsten and cobalt cemented carbide with "hard", "cobalt" two words in Chinese pinyin prefix "YG" and the percentage of cobalt content, such as YG6 said w(Co)= 6% cemented carbide, the rest of the composition is WC. The higher the content of cobalt, the higher the strength of cemented carbide, the better the toughness, and the lower the strength, the worse the wear resistance. The carbide tool with high cobalt content is used for rough machining with large impact and vibration, while the carbide tool with little cobalt content is suitable for precision parts processing.

2. Tungsten-titanium-cobalt cemented carbide:

The grade of tungstin-titanium-cobalt hard alloy is expressed by the percentage of "hard" and "titanium" Chinese pinyin prefix "YT" plus TiC. For example, YT14 means w (TiC) = 14% of hard alloy, and the other main chemical components are WC and Co. The higher the TiC content, the higher the hardness of hard alloy, the better the heat resistance, and the lower the strength, the worse the toughness. Therefore, the carbide tool with more TiC is suitable for precision parts processing with stable working conditions, and the carbide tool with less TiC is suitable for rough machining.

Tungsten-cobalt cemented carbide has better strength and toughness, and better grinding property. The cutting tools made by this kind of cemented carbide are suitable for processing cast iron and non-ferrous metals. Tungstin-titanium-cobalt hard alloy has better wear resistance and heat resistance, and the tool made of this kind of hard alloy is suitable for processing steel.