# Effect of In Situ Synthesized Al2O3 and TiC on the Microstructure and Properties of 6061 Aluminum Matrix Composites

## TL;DR

This paper studies how adding Al2O3 and TiC to 6061 aluminum affects its structure and performance, finding improved strength and wear resistance at specific conditions.

## Contribution

The novel in situ synthesis of Al2O3 and TiC in 6061 aluminum composites is explored for enhanced mechanical and wear properties.

## Key findings

- Composites sintered at 1200 °C showed a tensile strength of 246 MPa and 12.7% elongation.
- The 6061 Al-12% (TiO2 + C) composite had the lowest friction coefficient and wear rate under 30 N load.
- Delamination wear dominated in pure aluminum, while abrasive wear was observed in the composite.

## Abstract

Al2O3-TiC/6061Al composites were fabricated via in situ powder metallurgy using 6061 Al, TiO2, and graphite powders as starting materials. The effects of sintering temperature and ceramic particle content on the microstructure and mechanical properties of the composites were investigated. The wear performance of composites sintered at 1200 °C with varying ceramic particle content was also examined. The results indicate that the microstructure of the composite varied with the sintering temperature. At 1000 °C and 1100 °C, the microstructure primarily consisted of Al3Ti, Al2O3, and TiC phases. At 1200 °C and 1250 °C, the microstructure was predominantly composed of Al2O3 and TiC phases. The 6061 Al-12% (TiO2 + C) composite sintered at 1200 °C exhibited a tensile strength of 246 MPa, an elongation of 12.7%, and a microhardness of 104.2 HV0.1. Regarding wear performance, the wear behavior of the composites under different loads at 1200 °C was studied. Under a 30 N load, the 6061 Al-12% (TiO2 + C) composite demonstrated the lowest friction coefficient and wear rate, measured at 0.253 and 0.396 mm3·N−1·m−1, respectively. Analysis of the worn surface morphology under a 30 N load indicates that the dominant wear mechanism for the 6061 aluminum alloy is delamination wear, whereas for the 6061 Al-12% (TiO2 + C) composite, it is primarily abrasive wear.