Wear Resistance of the Surface-Modified Cast Iron by Laser Melting

—Laser Surface Modification of Cast Iron Aimed at Refining the Wear Resistance (Report 2)—

Abstract

The authors have studied on the laser surface modification of cast iron aimed at refining the wear resistance. It was already reported that cooling rate in solidification is varied by laser condition and that a fine martensite-ledeburite microstructure with hardness of about Hv 1000 was obtained by a pulsed laser. In this report, wear characteristics such as wear resistance and scuffing resistance were investigated by performing pin-on-plate sliding tests that demonstrate the friction between a piston ring and a cylinder bore. Surface-modified cast iron samples, especially irradiated by a pulsed laser properly, showed good wear resistance even under severe sliding conditions. The scuffing resistance depended on the countermaterial; CrN coated pins showed the higher scuffing resistance than hard Cr plated pins and nitrided pins.