Characterization of Mg-AZ91E/AlN composites by computed tomography

This study explores the synthesis and characterization of magnesium alloy AZ91E metal matrix composites (MMCs) reinforced with aluminum nitride (AlN). The AZ91E alloy was infiltrated into AlN performs at 850 °C without pressure. 3D image analysis, with a voxel size of 950 nm, enabled phase segmentation, revealing and quantifying AlN particles and the Mg-AZ91E matrix. Isolated porosity and the β-Mg₁₇Al₁₂ precipitate were identified through Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Permeability simulations of the green compact illustrated the flow paths followed by the liquid during infiltration. The composite exhibited approximately 0.5% porosity. The β-Mg₁₇Al₁₂ phase was located within the Mg-AZ91E matrix, confirming it is not a result of interphase reactions. Thermal conductivity simulations based on the actual microstructure demonstrated significant improvement after infiltration, aligning closely with the experimentally measured value. This study validates that 3D image analysis is an effective method for estimating the thermal properties of MMCs.