Thermal shock and fatigue resistance of tungsten materials under transient heat loading

摘要

Transient heat loading tests were performed on rolled pure tungsten (PW) and lanthanum oxide doped tungsten (WL10) as well as swaged + rolled potassium doped tungsten (W-K) samples using an electron beam. In thermal shock tests, the cracking threshold was 0.44-0.66,0.17-0.22 and 0.44-0.66 GW/m(2) for PW, WL10 and W-K, respectively. The melting threshold was over 1.1 GW/m(2) for PW and W-K while 0.66-0.88 GW/m(2) for WL10. In thermal fatigue tests, the obvious roughening threshold was over 1000 cycles for PW and WU 0 while 1-100 cycles for W-K. The cracking threshold was 100-1000 cycles for PW, 1-100 cycles for WL10 and over 1000 cycles for W-K alloy. WL10 displayed worse thermal and fatigue resistance while W-K exhibited better properties compared with PW, which was attributed to differences in thermal-mechanical properties of the three tungsten alloys, in addition to the size and number density of La2O3 particles and potassium bubbles. (C) 2014 Elsevier B.V. All rights reserved.