抄録
There are solid, liquid and gas processes in the diffusion coating technics and the first one is divided into a number of practical technics using paste, powder, etc. Moreover, this technics has lots of variations such as single, composite and progressive processes.
By means of combination of the above mentioned processes and a high frequency heating method, it is expected that hardness, resistivity to abrasion, toughness and durability of cemented carbides can be improved considerably.
Results obtained in this study are summarized as follows.
(1) Cemented carbide WC-Co system increased its weight after the treatments of boronizing without any protection atmosphere and its increasing rate depended on the Co contents in the alloy. On the contrary, siliconizing treatment in the same atmosphere caused to decrease its weight because of peeling.
(2) Intermetallic compounds formed by these reactions were identified by the X-ray diffraction pattern. They were Co3B in boronizing and Co2Si in siliconizing.
(3) Changes of hardness and transverse rupture strength of this alloy after these treatments depended on the treated conditions; in boronizing disproportionally, but in siliconizing proportionally.
(4) In order to carry out siliconizing effectively, a high temperature treatment more than 1000°C is recommended.
