Since the advent of cemented carbide in 1923, people have continuously optimized its properties mainly by improving its sintering process, preparing ultra-fine WC-Co composite powder, and surface strengthening. However, due to the problems of complex equipment, high preparation costs, and high technical difficulty in the above method, it has restricted the transformation and upgrading of my country’s cemented carbide industry to a certain extent. Cryogenic treatment is a new material with low energy consumption, no pollution, and easy operation. Modification technology can effectively improve the mechanical properties, wear resistance, dimensional stability, corrosion resistance, electrical conductivity/thermal conductivity and other properties of materials, and has been maturely used in the industrialization of various materials. Therefore, using cryogenic treatment to optimize the properties of cemented carbide can effectively avoid the shortcomings of traditional modification methods and provide a new process route for improving the properties of cemented carbide efficiently and at low cost.
However, due to the late start of research on cryogenic treatment of cemented carbide, it still faces many problems in terms of cryogenic treatment process and modification mechanism. In recent years, people have studied the changes in various aspects of properties of cemented carbide after cryogenic treatment in the laboratory. At the same time, in-depth research has been carried out on the influence of cryogenic treatment process parameters and changes in macroscopic properties, as well as the microscopic mechanisms of changes in macroscopic properties. And achieved certain results.
A large number of tests have shown that cryogenic treatment can significantly improve the flexural strength, wear resistance and cutting performance of cemented carbide, and can effectively extend the service life of cemented carbide tools, while having little effect on its hardness and toughness. The improvement effect of cemented carbide properties is closely related to the cryogenic treatment process parameters. Lower cryogenic treatment temperature and longer holding time are conducive to the improvement of its performance, but the performance of cemented carbide does not increase with the decrease of cryogenic treatment temperature and holding time. Extended and linear changes. Generally speaking, there are optimal cryogenic treatment process parameters for cemented carbide of specific compositions. The strengthening mechanism of cryogenic treatment on the service performance of cemented carbide is mainly the martensitic transformation of the bonding phase Co, the dispersion precipitation of the eta phase, and the change of the residual stress state on the material surface.
Post time: Mar-05-2024
