Effects of loading velocity on fracture toughness of a SiCw/A6061 composite at elevated temperatures

摘要

The influence of loading velocity on the fracture toughness of a SiC whisker reinforced 6061 aluminum alloy composite was investigated at elevated temperatures. A precracked three-point bend specimen configuration was selected for fracture toughness measurement, with tests being conducted at loading velocities of 10{sup}(-2) to 10 m s{sup}(-1), and at temperatures up to 473 K. The results showed that the fracture toughness increases with increasing loading velocity, but the difference with respect to room temperature is small, because the fracture toughness decreases slowly with increasing testing temperature. The composite material failed mainly by whisker pull-out and whisker breaking.