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

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