Investigation of microstructure and tribological properties of titanium-aluminide reinforced aluminum matrix composite friction surfaced on AA1050 aluminum

Abstract

Abstract In this study, the microstructure and wear resistance of titanium-aluminide reinforced Al-Zn-Mg-Cu alloy matrix composite friction surfaced on AA1050 aluminum were investigated. The titanium-aluminide reinforced Al-Zn-Mg-Cu alloy matrix composite was fabricated using a semi-solid casting procedure at 630 °C. The results show that by increasing the consumable rod rotational speed from 800 to 1200 rpm, the width and height of the coating increased 15 and 16%, respectively, reaching 21.4 and 1.4 mm, respectively. The findings on the coating grain size show that the effect of plastic strain is dominant over the effect of temperature. Therefore, the coating grain size decreased by increasing plastic strain. By increasing the rotation speed from 800 to 1200 rpm, the coating hardness and shear strength values increase from 121.6 to 136.3 HV and 262.2 to 274.3 MPa, respectively. Also, the titanium-aluminide reinforcement does not have much effect on the thermal stability of the coating. After artificial aging heat treatment, TiAl intermetallic compounds, in addition to the Ti3Al intermetallic compounds, are formed in the coating. By applying the coating at a rotational speed of 1200 rpm, a traverse speed of 125 mm min−1, and an axial feeding rate of 75 mm min−1, the wear resistance of the substrate increased by up to 151%, respectively.