Development of thermal spraying powder by crushing cast iron - study on recycle of cast iron by thermal spraying method (1st report)

摘要

At present, during the process of machining the cast iron, many chips have been produced. These chips are abolished except recycle using. However, considering the effective conservation of material resources, the recycle of these cast iron chips is a matter of the utmost concern. In this paper, recycle method applying to the thermal spraying is newly proposed for the ductile iron chips JIS-FCD450. Namely, by crushing and arranging these ductile iron chips, it is possible to make use of them for the thermal spraying powder. Obtained results are summarized as follows. (1) Since the crushed powder was flat and thin in shape, it was well melted under gas flame spraying process in comparison with the conventional powder. (2) Microstructure of the gas flame sprayed coat made from the crushed powder was constructed with piled up thin layers and had fewer blowholes than the conventional coat. (3) when the carbon was removed from the surface of the crushed powder by ultra sonic wave, substrate/coat interface strength changed to higher than that of the conventional coat regardless of powder size.