V元素对TiAlN涂层高温氧化行为的影响

Influence of V Element on High Temperature Oxidation of Ti-Al-N Coating

为了考察V元素对Ti-Al-N涂层高温氧化行为的影响,用多弧离子镀法在W18Cr4V1Co5高速钢试样表面涂镀了Ti-Al-N和Ti-Al-V-N涂层。对两种涂层试样在不同温度和不同时间下进行氧化处理。用SEM观测两种涂层的组织结构,用XRD分析其相组成,用GTA分析其升温氧化和恒温氧化动力学行为。实验结果表明,V的加入使涂层晶粒细化,组织更加致密;两种涂层均在750℃以后才测量到氧化增重;Ti-Al-N涂层的氧化转折点为920℃,超过920℃,涂层迅速氧化,逐渐失效;Ti-Al-V-N涂层在超过1000℃增重仍非常缓慢,并具有抗氧化保护的作用。V元素的加入大大降低了氧化速率,从而有效地提高了涂层的抗氧化性能。

In order to investigate the effects of V element on high temperature oxidation of Ti-Al-N coating, the Ti-Al-N and Ti-Al- V-N coating on the W18Cr4V1Co steel surface were coated by multi-arc ion plating, which the oxidation treatment was performed at various temperature for different time. The microstructure, phase component, and oxidation dynamics at isothermal and varieties of temperature for both coatings were characterized by SEM, XRD, and GTA analysis. The results show that adding V can make the grain fining and the structure densifying. The oxidation weight gain for both coatings did not exhibit until at temperature of 750 ℃. The initial oxidation temperature of Ti-Al-N coatings is 920 ℃ over which the coating is oxidated rapidly, while the oxidation weight gain of Ti-Al-V-N is still very low at temperature overl 000 ℃, which is of a protective effect of resistant to oxidation. Also ability of the resistant to oxidation for coatings increases by adding V element which can reduce the oxidation rate.