晶粒尺度和片层厚度对全片层γ-TiAl合金性能的影响

Influences of Grain Size and Lamellar Spacing on the Properties of Fully Lamellar γ-TiAl Alloys

研究了全片层 Ti- 46 .5 Al- 2 Cr- 1.5 Nb- 1V合金的显微组织与宏观力学性能之间的关系。研究表明 ,通过不同的热处理制度可以得到具有相同片层厚度的 4种晶粒尺度 ,以及晶粒尺度大约为 45 0 μm,片层厚度分别为 15 0 nm和5 0 0 nm的组织。材料的屈服强度随着合金晶粒尺度和片层厚度的增加而减小 ,符合 Hall- Patch关系 ,ky值为 1.82。材料的蠕变抗力随片层厚度的增加而减小 ,但是对晶粒尺度的变化不很敏感。

The relationships between mechanical properties and microstructural parameters of fully lamellar Ti 46 5Al 2Cr 1 5Nb 1V alloys have been studied. Fully lamellar microstructures with four different grain sizes for constant lamellar spacing and two different lamellar spacings for constant grain size have been obtained by means of various heat treatments. The results show that the yield strength increases as the grain size and the lamellar spacing decrease. The effect of lamellar spacing on the yield strength is great. The creep resistance decreases with increase of the lamellar spacing, but it is not sensitive to grain size in the range of 150 μm to 800 μm.