Effect of hot extrusion on microstructure and tribological behavior of Al2O3p reinforced 7075 aluminum-matrix composites

• Published in: Journal of Central South University Vol. 28; no. 8; pp. 2269 - 2284
• Main Authors: Lei, Yu-shun, Yan, Hong, Wei, Zhi-fan, Xiong, Jun-jie, Zhang, Peng-xiang, Wan, Jian-ping, Wang, Zhi-lu
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.08.2021; Springer Nature B.V
• Subjects: Aluminum base alloys; Aluminum matrix composites; Copper; Engineering; Extrusion rate; Hot extrusion; Magnesium; Metallic Materials; Microhardness; Microstructure; Optical microscopy; Precipitation hardening; Scanning electron microscopy; Transition layers; Tribology; Wear rate; Wear resistance; composites; 热挤压; microstructure; 7075 铝合金; 微观组织; 复合材料; 7075 alloy; hot extrusion; Al; 摩擦学行为; tribological behavior; O
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-021-4768-9

The effects of hot extrusion and addition of Al 2 O 3p on both microstructure and tribological behavior of 7075 composites were investigated via optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and transmission electron microscopy (TEM). The experimental consequences reveal that the optimal addition of Al 2 O 3p was 2 wt%. After hot extrusion, the Mg(Zn,Cu,Al) 2 phases partially dissolve into the matrix and generate many uniformly distributed aging precipitation particles, the Al 7 Cu 2 Fe phases are squeezed and broken, and the Al 2 O 3p become uniform distribution. The microhardness of as-extruded 2 wt% Al 2 O 3p /7075 composites reaches HV 170.34, increased by 41.5% than as-cast composites. The wear rate of as-extruded 2 wt% Al 2 O 3p /7075 composites is further lower than that of as-cast composites under the same condition. SEM-EDS analyses reveal that the reinforced wear resistance of composites can put down to the protective effect of the Al 2 O 3p reinforced transition layer. After hot extrusion, the transition layer becomes stable, which determines the reinforced wear resistance of the as-extruded composites.