微量氧环境下热处理温度对Zr-1%Nb合金力学性能的影响

Effect of heat treatment temperature on mechanical properties of Zr-1%Nb alloy under trace oxygen environment

采用扫描电镜、X射线衍射仪及万能试验机等研究了微量氧环境下400、800和1200℃不同温度保温300 s对Zr-1%Nb合金力学性能的影响。结果表明:与未热处理的合金相比,400℃热处理后Zr-1%Nb合金的力学性能未发生明显变化;800℃热处理后,合金的塑性降低,压缩时外表面产生大量微裂纹;1200℃热处理后,压缩时合金出现了脆性断裂。热处理后合金样品的表面发生了氧化,氧化产物主要为ZrO2相。随着热处理温度的升高,Zr-1%Nb合金的氧化程度逐步加深,并且1200℃热处理后试样氧化层的厚度显著增加,内部出现大量裂纹。

Effects of heat treatment at different temperatures(400℃,800℃,and 1200℃)for 300 s on mechanical properties of Zr-1%Nb alloy under trace oxygen environment were studied by means of scanning electron microscopy,X-ray diffractometer and universal testing machine.The results show that compared with the Zr-1%Nb alloy without heat treatment,after heat treatment at 400℃,the mechanical properties of the Zr-1%Nb alloy do not changed obviously.After heat treatment at 800℃,the plasticity of the alloy decreases,and a large number of micro-cracks occur on the outer surface of the alloy during compression.After heat treatment at 1200℃,brittle fracture of the alloy occurs during compression.After heat treatment,the surface of the alloy sample is oxidized,and the oxidation product is mainly ZrO2 phase.With the increase of heat treatment temperature,the oxidation degree of the Zr-1%Nb alloy gradually deepens,and the thickness of oxide layer increases significantly after heat treatment at 1200℃,and a large number of cracks appear inside of the alloy.