钛合金表面等离子喷涂热障涂层性能的研究

Study on Properties of Plasma-sprayed Thermal-barrier Ceramic Coating on Titanium Alloy Surfaces

用等离子喷涂法在钛合金(Ti6Al4V)表面制备NiCrAlY+(ZrO2+Y2O3)陶瓷热障涂层。用XRD、SEM检测了涂层的金相组织、结构及形貌。对喷涂前后的试样在600℃进行了高温氧化实验,给出了氧化动力学曲线。结果表明,钛合金经等离子喷涂处理后表面形成陶瓷热障涂层且与基体结合紧密,涂层的厚度约为210μm。所形成的热障涂层显著地提高了钛合金的高温抗氧化性能,降低了氧化速率,致密的氧化膜对继续氧化有阻碍作用。

The thermal-barrier ceramic coating with the bottom layer of NiCrAIY and the top layer of （ZrO2＋ Y2O3） was prepared by the plasma spraying technique on the surface of titanium alloy. The microstructure, structure and morphology of the coating were analyzed by XRD and SEM. The high temperature oxidation resistance of the plasma-sprayed samples at 600℃ was investigated. The oxidation kinetics curve was worked out. The results show that the thickness of coating is about 210 um. The plasma-sprayed thermal-barrier ceramic coating can improve the high temperature oxidation resistance of titanium alloy. The oxidation rate of titanium alloy is greater than that of plasma-sprayed thermal-barrier ceramic coating, The oxidation film of plasma-sprayed sample was very dense and is not easily exfoliated. The dense oxidation film prevents the titanium alloy from more oxidation.