Effect of ball milling and solid solution treatment on microstructure and mechanical properties of ZrMgMo3O12p/2024Al composites

The 10 vol% ZrMgMo3O12/2024Al composites were fabricated using the powder metallurgy process and consolidation via vacuum hot pressing. The effects of the ball milling process and solution treatment time on the composites’ microstructure, Vickers hardness, and compressive properties were studied. Increasing the ball milling speed and extending the ball milling duration reduce the size of ZrMgMo3O12 particles, resulting in a more uniform dispersion within the aluminum matrix. Extending the solution treatment duration facilitates the dissolution of more primary Al2Cu phase into the aluminum matrix reducing the presence of coarse primary Al2Cu phase and increasing the number of fine Al2Cu precipitates formed during the aging process. The results indicated that an appropriate increase in ball milling speed, extension of ball milling duration, and solution treatment time can enhance the Vickers hardness and room temperature compressive strength of the composites. Specifically, the composites processed with a ball milling speed of 350 rpm for 6 h, a solid solution treatment at 495 °C for 24 h, and an aging treatment at 190 °C for 8 h exhibited a Vickers hardness of 277 HV and a compressive yield strength of 687 MPa, along with a compressive strain of 7.8 %.