Fly Ash, TiO2, hBN, and B4C Nanoparticle Reinforcement: A Novel Approach to Magnesium Metal via Powder Metallurgy

The study explores the impact of fly ash and nanoparticle reinforcements (TiO₂, hBN, B₄C) on magnesium alloy properties. Fly ash increases porosity and reduces density. All reinforcements reduce conductivity, and B₄C significantly decrease thermal expansion. This decrease is attributed to the particles' barrier effect, lower CTEs, and ability to promote uniform particle dispersion. The distribution of reinforcing particles varies, with B₄C and hBN showing the most even dispersion. All reinforcements improve particle homogeneity, enhancing microhardness, with B₄C exhibiting the most significant enhancement of 72%. All composite materials show increased compression strength, with B₄C showing the most significant improvement of over 50%. The Mg hybrid composites display higher longitudinal and shear velocities than pure Mg. B₄C shows the most substantial increase, with a 30% rise in longitudinal velocity and a 22% increase in shear velocity. Moreover, all composite materials exhibit larger Young's and shear moduli than pure Mg. B₄C demonstrates the most notable enhancement, with a 50% increase in Young's modulus and a 45% increase in shear modulus. These enhancements result from the composites' heightened rigidity and decreased mass caused by the reinforcements, further amplified by the optimized spatial distribution of particles.