PREPARATION OF TAPE TRAVELLING PARTS

PURPOSE:To obtain magenetic recording tape travelling parts enhanced in tape travelling performance, reliability and life, by selectively etching in gas plasma travelling parts made of an Al alloy containing high hardness particles. CONSTITUTION:An Al alloy containing particles comprising a high hardness material such as silicon is used as a base material to fabricate the tape travelling parts 1 having a predetermined dimension and surface roughness of a cylinder. Said parts 1 are placed in a vacuum container 2 and a gaseous carbon tetrachloride is introduced into the vacuum container 2 from a gas introducing pipe 7. When negative potential is applied to the cylinder 1 from a DC power source 5 through a negative electrode 4, carbon tetrachloride is converted to plasma and dry etching is carried out by chemical reaction due to active particles present in said plasma and sputtering effect due to charged particles therein. In this case, Al is selectively etched in a large amount as compared to silicon particles and tape travelling parts having high hardness particles exposed on the surface thereof are obtained.