EFFECT OF SILICON ON THE OXIDATION KINETICS AND MICROSTRUCTURE OF THE SURFACE LAYER OF TaCr2 ALLOYS OBTAINED BY VACUUM HOT PRESSING

Authors：Yao, Jing^*; Lu, Shiqiang; Xiao, Xuan; Deng, Liping

Source：METAL SCIENCE AND HEAT TREATMENT, 2022, 64(1-2): 121-126.

DOI：10.1007/s11041-022-00771-4

• Laves phase
• TaCr2
• vacuum hot pressing
• microstructure
• high-temperature oxidation

The effect of addition of 0 -10 at.% Si on the microstructure and high-temperature oxidation resistance of alloys based on TaCr2 Laves phase and obtained by mechanical alloying with subsequent vacuum hot pressing is studied. Phase and x-ray diffraction analyses of ready alloys are performed before and after oxidation. The surface morphology of the specimens is studied by electron microscopy. It is shown that silicon promotes the appearance of a TaCr2 phase of hexagonal modification. An oxide film with a duplex structure represented by an outer layer of Cr2O3 and an inner layer of TaCrO4 forms on the surface of the alloy due to oxidation. Alloying with 5 - 8 at.% Si raises the resistance of the TaCr2 alloy to oxidation at 1437 K, and the kinetics of the isothermal oxidation is describable by a parabolic law.

• Institution
  南昌航空大学