LAUSR

Abstract Mg-alloy (AZ91D) based composites reinforced by Ti 2 AlC MAX phases particles were firstly fabricated by the stir casting technology. The mechanical properties in relationship with the microstructure were carefully investigated. The Ti 2 AlC particles were generally distributed along α-Mg grain boundaries and strongly impeded the dendritic growth of α-Mg. Yield strength, Vikers hardness, ultimate compressive strength, and Young's moduli increased with increasing Ti 2 AlC fraction in composites, while the optimized ultimate tensile strength was found for 10 vol% of Ti 2 AlC. The theoretical calculation on tensile yield strength reveals that individual strengthening contribution was mainly from Hall-Petch strengthening and Forest strengthening, followed by Orwan strengthening effect. The elastic moduli were predicated by Halpin-Tsai approach the mixture rule and the Hashin and Shtrickman equation. One aspect ratio of 3 was found by fitting Halpin-Tsai approach with experimental results. In-situ tensile test revealed the cracks were initiated in Ti 2 AlC particles and propagated along α-Mg grain boundaries. During this process, no decohesion occurred at the Ti 2 AlC and AZ91D interfaces.