Process for producing alumina coating composed mainly of alpha-type crystal structure, alumina coating composed mainly of alpha-type crystal structure, laminate coating including the alumina coating , member clad with the alumina coating or laminate coating, process for producing the member, and physical vapor deposition apparatus

The present invention provides a process for producing an alumina coating composed mainly of ±-type crystal structure, comprising, when forming an alumina coating composed mainly of ±-type crystal structure on a base material having a primary coating preliminarily formed thereon, forming a hard coating composed of a metal component containing Al as an unavoidable element and a compound of B, C, N, O, etc. as said primary coating, oxidizing said hard coating to form an oxide-containing layer, and then forming an alumina coating composed mainly of ±-type crystal structure on said oxide-containing layer. The present invention further provides a process for producing an alumina coating composed mainly of ±-type crystal structure, comprising, when forming an alumina coating composed mainly of ±-type crystal structure on a base material having a primary coating preliminarily formed thereon, forming a hard coating composed of a metal whose standard free energy for oxidation generation is greater than that of aluminum and a compound of B, C, N, O, etc. as said primary coating, oxidizing said hard coating to form an oxide-containing layer, and then forming an alumina coating composed mainly of ±-type crystal structure on said oxide-containing layer.