Improvement in hardness, wear rate and corrosion resistance of silicon bronze using gas tungsten arc

Abstract

This study examines the effects of Gas Tungsten Arc (GTA) modification of silicon bronze alloy on the microstructure of the alloys and their surface properties, viz., hardness, wear rate and corrosion resistance. The substrate was modified at three different heat inputs in either argon or nitrogen atmosphere. It is observed that modification in nitrogen atmosphere causes enhanced heat transfer to the substrate, resulting in improved hardness, depth of penetration and decreased wear rate, compared to that under argon atmosphere followed by quick solidification. Modification under nitrogen environment resulted in ∼60% reduction in corrosion rate, with evidence of significant localized corrosion. Thus, it may be concluded that surface modification of silicon bronze alloy by GTA results in finer grains, increased surface hardness, decreased wear rate and improved corrosion resistance.