Thermal Stability and High-Temperature Oxidation Behavior of W-Re Alloy

Abstract:

Superalloys have a very important position in the development of nuclear fusion and other fields. To study the stability and oxidation resistance of W-3%Re alloy at high temperature, the thermal stability experiments of W and W-3%Re alloy were conducted at the temperature of 500, 700, and 900 ℃ for 6 h. Oxidation experiments were conducted at the temperature of 700, 800, and 900 ℃ for 18 h. The phase composition, oxidation kinetics, oxidation products, and surface morphology of the oxide film were analyzed by XRD, SEM, LSM800 automatic 3D morphology analyzer, and Hysitron TI Premier nanoindentation apparatus. The results show that the quality of the alloy increases with the prolongation of oxidation time. During the oxidation process, the grain size of W-3%Re alloy is reduced, the oxidation film forms faster, the surface oxide layer is gradually thicker, and the high temperature oxidation resistance of W-3%Re alloy is improved. Compared with W, the chemical stability of the Re oxide in W-3%Re alloy is higher. And W-3%Re alloy shows a lower oxidation rate constant when it is oxidized at 700 ℃ for 18 h. At this time, the W-3%Re alloy is a weak oxidation grade, and the density of the oxide layer is improved to a certain extent during the oxidation process. This indicates that the addition of Re can improve the high temperature oxidation resistance of W material.