HIGH-TEMPERATURE DYNAMIC COMPRESSIVE PROPERTIES OF ZR-BASED AMORPHOUS ALLOY AND AMORPHOUS MATRIX COMPOSITE

Abstract

High-temperature dynamic compressive deformation behavior of Zr-based amorphous alloy and amorphous matrix composite containing ductile beta crystalline phases was investigated in this study. Dynamic compressive tests were conducted in the temperature range from room temperature to 380 degrees C using a compressive Kolsky bar, and then the test data were analyzed in relation to microstructure and fracture mode. Dynamic compressive test results indicated that both the maximum compressive stress and total strain of the amorphous alloy and composite decreased with increasing test temperature because shear bands could propagate rapidly as the adiabatic heating effect was added at high temperatures. Above the glass transition temperature, the total strain decreased more abruptly than that in the temperatures between room temperature and 300 degrees C according to the appearance of the crystallization of amorphous phases. The maximum compressive stress and total strain of the amorphous composite were higher than those of the amorphous alloy over the tested temperature range because beta phases played a role in forming multiple shear bands. These findings suggested that applying the evaluation criteria for mechanical proper-ties measured under room-temperature quasi-static loading could cause risks when Zr-based amorphous alloys were used at high temperatures under dynamic loading conditions.