Improvement in tribological and hydrophobic properties of thrust plate of gear pump through oxyacetylene flame spraying in diverse cooling Medium

Abstract

In the present research, a flame spraying technique with diverse cooling mediums has been used to enhance the surface properties of the thrust plate of a gear pump made of aluminium alloy. The influence of flame spraying on the surface of the thrust plate with reference to the coefficient of friction, wear volume, micro-hardness, change in microstructure, surface roughness, and formation of hard phases have been highlighted in this research. The field emission scanning electron microscopy micrograph indicates the formation of fine-grain microstructure in the flame-hardened surfaces due to the formation of the hard phases. Dry sliding wear test results indicate the improvement in friction coefficient in the hardened sample with olive oil cooling as compared to the parent surface. Optical profile analysis of the wear track shows the lower wear volume for the hardened samples with oil cooling as compared to the parent material. Micro-hardness of the flame-hardened surface increased from 80 HV0.5 (parent surface) to a maximum value of 132 HV0.5 (flame-hardened with oil-cooled). A significant improvement in water contact angle (from 740 to 970) also has been observed, indicating the enhancement in the hydrophobic nature of flame-hardened surfaces.