Thermal Fatigue Damage of Tungsten Under High Heat Load

The thermal fatigue damage of recrystallization tungsten with different cycle times was studied at power of 141.5 MW/m2 by electron beam thermal fatigue test system which was built independently in the laboratory. Changes in surface topography after thermal shock in many cycles were observed by scanning electron microscopy (SEM). Changes of three-dimensional morphology and surface roughness were detected by Atomic force microscope (AFM) and the surface hardness was tested after thermal fatigue. The results show that with the increase of the cyclic number, thermal fatigue damage intensifies. The surface of tungsten starts to be molten at 1000 cycles. The surface roughness changes linearly with the cycle number; it is increased firstly and then decreased because of the fatigue hardening. © 2018, Northwest Institute for Nonferrous Metal Research. Published by Elsevier BV. All rights reserved.