DRY SLIDING WEAR BEHAVIOUR OF SAND CAST CU-11NI-6SN ALLOY

Abstract

Wear behaviour of sand cast Cu-11Ni-6Sn alloy was studied using pin-on-disc wear tester with alloy steel disc as counterpart on dry sliding wear conditions. The alloy was prepared from pure elements and melted in an electric furnace under argon atmosphere and cast into sand moulds. The cast rods were homogenized, solution heat treated and aged. Specific wear rate and coefficient of friction were measured in a sliding speed of 191 rpm, 287 rpm and 382 rpm and different normal forces of 10 N, 15 N and 20 N. Hardness of the specimen was found to increase by the aging process and it reached its maximum value, after which it decreased. The specific wear rate was found to increase with the increase in normal load and it decreased with the increase in speed. Co-efficient of friction is independent of hardness of the alloy and dependent on both applied load and speed. The strength of the material is increased by a technique called spinodal decomposition and aging process. In the case of Cu-Ni-Sn system the various alloy composition was not tested for tribological behaviour. Only few alloy compositions are studied. So in this case we have taken Cu-11Ni-6Sn alloy composition. The products made by Cu-Ni-Sn alloy is less costlier compared to Cu-Be products without health hazard and used as high performance connector materials in electronics applications, bearing material in aerospace and mining industries, friction-reducing and anti-wear materials to make high performance bearings for aerospace, roller cone, rock bit and heavy duty mobile industrial equipment.