Tungsten carbide button gradient structure optimization
In the late 1980s, Sweden and other countries developed a new type of rock-hardened Tungsten carbide button. Gradient structure cemented carbide, also known as multi-structure or multi-phase cemented carbide, is characterized by a gradient distribution of components or structures, which simultaneously provides high wear resistance and high toughness. The principle of preparation of the gradient structure cemented carbide is: using a low carbon cemented carbide, obtaining a hard alloy containing '' phase by vacuum sintering, and treating it in a carburizing atmosphere to change the distribution of the Co binder phase, making the cemented carbide different The content of the Co is different. This type of cemented carbide exhibits a gradient distribution of Co in the structure, that is, the outermost layer of the cemented carbide is a Co-poor layer lower than the nominal Co content of the alloy, and the intermediate layer is a Co-rich layer higher than the nominal Co content of the Tungsten carbide button. The inner layer is a three-phase microstructure of WC and Co 77.