Importance of Al2TiO5 particle on the mechanical and wear performance of stir cast AA6061 composite using Central Composite Design

This study investigates the mechanical and wear properties of AA6061 composites reinforced with monosynthesized Al₂TiO₅ particles. Bottom pouring and stir casting were employed to achieve uniform dispersion of Al₂TiO₅. Five composite samples were fabricated with varying Al₂TiO₅ weight percentages (wt%) (0, 1, 2, 3, and 3.5) while maintaining a constant stirring speed of 400 rpm. Tensile strength, impact energy, and microhardness were evaluated according to ASTM standards. Wear rate and coefficient of friction (CoF) were measured using a Pin-on-Disc apparatus on samples prepared through ASTM G99. Composites reinforced with 2 wt% and 3.5 wt% Al₂TiO₅ exhibited the highest tensile strength (215.96 MPa) and impact strength (12.6 J), respectively. Microhardness increased significantly in samples 6R1 (75.37 HV), 6R2 (83.75 HV), and 6R3 (91.6 HV) compared to 6R0 (71.52 HV) and 6R3.5 (72.26 HV). Based on the finding that 1, 2, and 3 wt% Al₂TiO₅ reinforcement improved hardness, RSM optimization was applied to these compositions to further adapt the wear rate and CoF. Field emission scanning electron microscopy (FESEM) was used to examine the worn surface morphology of the composites and understand how Al₂TiO₅ particles influence wear mechanisms. The 3 wt% Al₂TiO₅ reinforced composite demonstrated an 83.5% increase in wear resistance compared to other samples under a 10 N load and 1600 m sliding distance.