| 摘要 |
PURPOSE:To easily produce a surface hardened body having high accuracy at a low cost by working a tempered base material, coating the surface thereof with ceramics, temporarily calcining the coating and subjecting the material to finished working to the final size then to normal calcining and surface finishing. CONSTITUTION:The tempered base material is worked to the size slightly smaller than the final finish size and thereafter the surface of the base material is coated with the ceramics to the size slightly larger than, the final finish size. The coated base material is temporarily calcined to the extent that the above-mentioned ceramic particles have suitable binding strength and thereafter the base material surface is worked to the final finish size. The base material is then immersed into a soln. of a chromic compd., etc., as necessary, to impregnate said compd. into the ceramic pores. The base material is subjected to the normal calcining to form the thoroughly calcined body securely bound with the ceramic particles; further the base material is subjected to surface finishing such as finishing by polishing. The surface hardened body of a screw for an injection molding machine, etc., is thus obtd. |
