A Low-Temperature Modification to the Charphy Impact Test, with an Example Study of the Fracture Toughness of mg-12/100Li between 4.2 to 77 K

摘要

A modification to the Charpy test for measuring impact fracture toughness has been developed that permits the speciment to be bathed in flowing liquid helium while mounted on the testing machine's anvil immeditely prior to impac.t This method permits samples to be tested at any temeprature between 4.2 and 77 K, which extends the Charpy test to temeprtures lower than those acheivable by the conventioanl liquid bath immersion technique. A body-centered cubic Mg-12/100Li single-pahse alloy was tested by this new method and found to have anomalously high impact fracture toguhness in the temeprature range 4.2 to 77 K.