Effect of extrusion on the thermal expansion behavior of Al18B4O33 whisker-Mg composites

 The thermal expansion behaviors of AZ91D alloy and Al18B4O33 whisker (w)-AZ91D fabricated by different techniques were investigated at 30-300 °C. The results indicate that these behaviors were greatly influenced by extrusion forming, which reduced the coefficients of thermal expansion (CTE) of AZ91D and Al18B4O33w-AZ91D and resulted in negative strain. The residual stresses could be eliminated by thermal cycling. The CTE of the whisker-reinforced composites could be predicted accurately by micromechanical modelling.