Effect of calcium on mechanical and tribological properties of Mg-Sn alloy system fabricated by powder metallurgy (PM) process

Abstract

The present investigation pertains to the fabrication of Mg–Sn–Ca alloys by powder metallurgy process. The elemental powders of Mg, Sn and Ca were blended and compacted with the compositions of Mg- 2 wt% Sn, Mg- 2 wt% Sn- 1 wt% Ca, Mg -2 wt% Sn- 2 wt% Ca. The green compacts sintered in the microwave furnace at the temperature of 400°C under the inert environment. Archimedes principle used to measure its density. Microstructural studies performed using an optical microscope and Vickers hardness tester did hardness test. It observed that the hardness of Mg-2Sn increases with increase of calcium up to 1%. However, with the further increase in calcium percentage hardness decreased. Therefore, it was concluded that the calcium percentage more than 1 wt.% is detrimental to Mg-Sn system. Dry sliding wear test was also performed on the pin-on-disc machine, the cumulative weight loss of the Mg-2 wt% Sn-1 wt% Ca was lowest among all, it was attributed to high hardness of materials which follows the Archard’s law and average coefficient of friction was decreasing in nature with normal load.