Abstract
TiB2/Mg-4Al-1.5Si composites were subjected to hot extrusion and subsequent annealing, and the creep resistance of the extruded composites (Ex-COM) was compared with that of the annealed composites (EA-COM) and as-cast composites (Cast-COM). Grain refinement and numerous low-angle grain boundaries (LAGBs) within elongated deformed grain resulted in a decreased creep resistance for the Ex-COM, with a steady-state creep rate increasing by 4.8 times compared to the Cast-COM. A slightly coarsened but more uniform equiaxed grains, which have high-angle grain boundaries (HAGBs), led to the optimal creep resistance for the EA-COM. The creep mechanism is primarily dominated by grain boundary sliding for the Ex-COM, while it is possibly controlled by the co-effect of dislocation climb and second-phase strengthening effect for the EA-COM.
Get full access to this article
View all access options for this article.
