Effect of yttrium oxide on microstructure and mechanical properties of functionally graded magnesium matrix composites.

Over the last decade, there has been a steady increase in the amount of magnesium scrap sourced from manufacturing processes due to the rapidly growing market for magnesium alloys in various industries. As a result, the reuse of magnesium becomes extremely beneficial for cost reduction, natural resource preservation, and environmental protection, as it gives scrap magnesium a new lease on life. The reuse of AZ91 magnesium alloy chips for producing functionally graded composites reinforced with yttrium oxide (Y 2 O 3) to enhance microstructure and mechanical properties was investigated in this paper. The manufacturing method for this study involves: (1) collecting and cleaning magnesium chips, (2) pre-mixing them with Y 2 O 3 particles, (3) melting and blending the compositions using a stir casting method, and (4) finally pouring it into a centrifugal casting to produce the functionally graded composite. The microstructure of the AZ91 matrix was examined, and it indicated a well-distributed gradient of Y 2 O 3 particles with little agglomeration. The estimated concentration of particles (which ranged from 40.35% to 32.1% area) closely matched the experimental data (which ranged from 43% ± 1.5% to 28% ± 1.5% area). The study also revealed that particle concentration had a substantial influence on the mechanical properties, with the outer zone outperforming both the middle and inner zones. In the outer zone, the gradient composite had a hardness of 106.89 ± 1.25 HV, a tensile strength of 197.39 ± 2 MPa, and a compressive strength of 335.29 ± 5 MPa. Furthermore, the findings demonstrated the feasibility of employing chip waste to make graded composites, providing a feasible technique for reusing magnesium chips created during machining procedures. This research sheds new light on the use of magnesium chips as a matrix material in the casting of functionally graded composites. [Display omitted] • ·Functionally graded AZ91/ Y 2 O 3 composite using magnesium chips as matrix was produced successfully via centrifugal casting. • Microstructure analysis showed a well-distributed Y 2 O 3 particle gradient, indicating successful reinforcement integration. • The outer zone showed superior mechanical properties, with increased hardness, tensile strength, and compressive strength. • Excellent agreement of particle concentration in AZ91 matrix alloy was achieved for theoretical and experimental results. • The effect of the capture and pushing of particles during the solidification process was discussed in detail. [ABSTRACT FROM AUTHOR]