Experimental studies on mechanical properties of Al-7075/TiO2 metal matrix composite and its tribological behaviour

Abstract

This study explores the fabrication and characterization of an Al-7075/TiO2 metal matrix composites (MMCs) through stir casting, varying TiO2 contents from 2% to 10%. Various tests, including tensile, hardness, and elastic indentation modulus testing, dynamic mechanical analysis, microstructural evaluation, and XRD, were conducted. Tribological analysis involved tribo-pairs of an EN31 disc and a smooth MMCs pin, using a high-temperature Pin-on-disc setup. Microstructural analysis of Al-7075/TiO2 MMCs revealed uniform TiO2 distribution, grain refinement, and enhanced mechanical properties, with XRD confirming structural changes. Tensile tests showed improved ultimate force and stress with increasing TiO2 content, indicating potential for high-strength applications. Hardness assessments demonstrated progressive improvements in Martens, Elastic Indentation, and Vickers Hardness, highlighting the material's suitability for critical wear and tribology applications. The composites exhibited enhanced damping flexural characteristics, especially with 8% TiO2. Maximum and minimum modulus values are reported as 98.9 GPa at 25 °C and 77.3 GPa at 350 °C for 8% TiO2 mix MMC. Tribological performance was improved with lower COF values and wear rates. At elevated temperatures, the wear behavior varied with TiO2 content, influenced by factors such as heat generation and localized welding.

Keywords

• Tribology and wear
• Titanium dioxide
• Metal matrix composites
• Dynamic mechanical analysis
• Inclusive innovation