合金元素对钛材热氧化动力学的影响

Abstract

选用TA18钛合金和TA2纯钛为试验材料，在箱式电阻炉中进行热氧化处理,研究合金元素对钛材热氧化的影响。利用扫描电镜(SEM)观察热氧化后表面氧化层形貌，XRD衍射仪对表面氧化层进行相组成分析，采用静态增重法研究TA18钛合金和TA2纯钛在不同温度下的热氧化动力学。结果表明，热氧化后，TA18钛合金和TA2纯钛试样表面都形成了氧化层，但TA18抗热氧化性优于TA2。TA18钛合金表面形成的氧化膜由金红石型TiO2和少量Al2O3构成。而TA2纯钛热氧化后表面形成的氧化膜全部为金红石型TiO2。在相同的热氧化温度和时间下，TA18钛合金的热氧化增重比TA2慢，说明合金元素有利于提高钛材的抗热氧化性。 TA18 titanium alloy and TA2 pure titanium were used as materials, and the thermal oxidation process was carried out in a conventional muffle furnace; the oxide layer was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and thermal oxidation kinetics was studied by static gain weight method. The results show that the surfaces of both TA18 titanium alloy and TA2 pure titanium were oxidized, but TA18 had better thermal oxidation resistance than TA2. The oxide film formed on the surface of TA18 titanium alloy was dominated by rutile TiO2, and a small amount of Al2O3. While the oxide film formed on the surface of pure titanium in TA2 was rutile TiO2 only. When the oxidation temperature was 600 and 700, the oxidation kinetics curve was followed by the parabolic law. In the same thermal oxidation temperature and time, the thermal oxidation rate of TA18 titanium alloy was slower than that of TA2 pure titanium.