CERAMIC COMPOSITE CYLINDER AND ITS MANUFACTURE

PURPOSE:To obtain a cylinder of an injection molding machine or an extruding machine, which requires high wear resistance or corrosion resistance, inexpensively, by a method wherein a liner made of ceramics is fitted into a part of an inner circumferential surface of a metallic cylinder where wear resistance or corrosion resistance is required, and a lining layer made of wear-resistant or corrosion-resistant alloy is formed on the remaining part of the inner circumferential surface. CONSTITUTION:A liner 2 made of ceramics such as silicon nitride is fitted into an inner circumferential surface of a metallic cylinder 1. In the case where the liner 2 is of a part of an inner circumferential surface of the metallic cylinder 1 where wear resistance or corrosion resistance is required especially, for example, a cylinder of an injection molding machine, the liner 2 is arranged at the tip part of the cylinder 1. On the other hand, a lining layer 3 is formed on the remaining part of the inner circumferential surface of the cylinder 1. The layer 3 is comprised of a nickel group alloy obtained by composing wear-resistant and corrosion-resistant chrome boride and the inner circumferential surface of the same coincides with that of the liner 2. As the inner circumferential surface of this composite cylinder is formed of the liner 2 made of the ceramics and the lining layer 3 of wear-resistant and corrosion- resistant alloy, wear and corrosion of that part are mitigated and durable life is extended.