機械加工を複合化した精密溶射加工装置の開発 (第1報)

クリーンカット溶射法によるセラミックス被膜の密着性の向上

抄録

The purpose of the present study is to develop a new technology to raise the bond strength between ceramic coatings and bulk metals. A surface just after being cut is chemically active because of its high cleanliness and a moderate temperature above 100°C. On the basis of these characteristics of metal cutting, this paper proposes the clean-cut plasma spraying in which ceramic particles melted by a plasma heat source are sprayed on the machined surface immediately after the cut. When using a structural steel for the bulk metal and an alumina for the spray powder, the alumina ceramic coating attains to a thickness of 0.31 mm/pass, a hardness of 76 (SUPERFICIAL 30-N) and a bond strength of 38 kgf/cm². Thermal cycling and thermal shock tests of the coating also show that the cleancut spraying is superior to the conventional spraying where steel ball blasting is used for a pre-treatment.