Study on Microstructure, Mechanical Performance and Thermal Shock Resistance of Diffusion Welded Joint of ODS-W and TZC Alloy

摘要

The diffusion welded joint of oxide dispersion strengthened tungsten (ODS-W) and Mo-Ti-Zr-C alloy (TZC) was successfully fabricated with the use of spark plasma sintering (SPS) at a vacuum level of 10 Pa. This study systematically investigates the microstructure, mechanical performance, and thermal shock resistance of the ODS-W/TZC connector at four different temperatures, ranging from 1300 to 1600 degrees C. The diffusion distance between the W and Mo atoms at the interface of ODS-W/TZC joint raises as the sintering temperature increases, with a maximum diffusion distance of up to 2 mu m at 1500 degrees C, but then slightly decreases at 1600 degrees C. The ODS-W/TZC connector bonded at 1500 degrees C exhibits the best tensile performance, with tensile strengths of 459 MPa and 786 MPa at room temperature and 500 degrees C, respectively. A maximum hardness of 446 HV is obtained at the interface when the sample is sintered at 1600 degrees C. Thermal shock tests are conducted on the surface and interface of the ODS-W/TZC connector sintered at various temperatures. ODS-W/TZC samples prepared below 1500 degrees C were severely damaged, leading to exfoliation after laser thermal shock, while samples prepared above 1500 degrees C produced fewer damage cracks. Confocal laser scanning microscope (CLSM) analysis demonstrated that the ODS-W/TZC joint fabricated at 1500 degrees C exhibited substantially reduced height perturbation of both its surface and interface compared to that of ODS-W, providing evidence for its superior thermal shock resistance.

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