The effects of changes in test temperature and loading conditions on fracture toughness of a β toughened Zr-based bulk metallic glass composite

The effects of changes in test temperature from 150 K to 653 K on the fracture behavior and toughness of a β-toughened Zr-based bulk metallic glass (BMG) were investigated. Loading conditions under either displacement rate control or loading rate control were additionally investigated. While the composite toughness was higher than that of the previously tested monolithic amorphous material tested under identical conditions, the toughness of the composite was also significantly affected by changing either the test temperature or loading conditions. In particular, brittle fracture of the crystalline component in the composite was observed at the lowest temperatures and highest loading rates at T ≤ 505 K. This reduced the toughness of the composite compared to other combinations of loading rate and test temperature and was significantly different than results previously obtained on the monolithic amorphous material. The results are compared to other recent work on the monolithic BMG tested under similar conditions over the temperature range of 77–653 K.