| 摘要 |
This machine element, e.g. a drill bush (121), has a hardened main body (180) made of steel and an approximately 0.1 mm-thick lining (189). The lining (189) is composed of hard particles, such as tungsten carbide particles, which are distributed in a softer matrix, in particular chromium nickel, and bonded to the main body by the latter. The lining (189) is compact or has interspaces for lubricant between the tungsten carbide particles. A base coating of wet binder, which contains chromium nickel powder, and tungsten carbide particles is first of all dried onto the main body (180), the tungsten carbide particles in the wet binder being compacted by rotation or vibration of the workpiece. Binder and a measured quantity of chromium nickel powder are then applied and all the chromium nickel powder is melted at 1050-1110 DEG C with the workpiece rotating or vibrating. In the case of bushes with a small inside diameter, the longitudinal opening (181) of the main body is filled with lining composition and the opening (187) then pierced, by means of an electrode (188) for example. It is advantageous that the wear resistance of the lining corresponds to that of solid tungsten carbide whereas the coefficient of expansion of the machine element itself corresponds to that of steel. <IMAGE> |
