| abstract |
(57) [Summary] [Structure] A part of the surface including the sliding surface is covered with a film 1 containing at least 70% of WC and at least one of Ni, Cr and Co, and the other surface except the film 1 Is coated with a film 2 containing either or both of Ni and Cr. Furthermore, after Ni, Cr, Co contained in the film 1 and the film 2 are formed, It is melted at least once at the time of sleeve formation, and the void amount in the film is set to 3% or less in area ratio. [Effect] Compared to the conventional sleeve made of WC sintered body, the weight is about 1/2, and the base can be processed into screw holes. Since it is S, it is easy to handle, and the labor amount of the worker at the time of assembling work can be significantly reduced. |