活塞环表面CrTiAlN复合涂层的抗高温腐蚀性能研究

采用多弧离子镀技术,利用Cr靶和TiAl靶,在活塞环材料65 Mn钢基体上制备了CrTiAlN复合涂层,并对电镀Cr、CrN和CrTiAlN复合涂层在800℃下的抗高温腐蚀性能进行了比较分析,用扫描电镜、能谱仪和X射线衍射仪观察分析了样品表面高温腐蚀氧化膜。结果表明:CrTiAlN复合涂层具有优异的抗高温腐蚀性能,在800℃时仍具有良好的抗高温腐蚀性能,其氧化机理是O向涂层内部扩散氧化,在高温腐蚀过程中,CrTiAlN涂层中的Cr发生了选择性氧化,优先形成了Cr2O3,CrTiAlN涂层氧化层区域的结构由外至里组成顺序为Cr2O3、Al2O3+TiO2、(Cr,Ti,Al)N。涂层外层的Cr2O3氧化物有利于阻碍氧元素向涂层内部扩散,能够降低涂层的高温腐蚀速度。

Study on Hot Corrosion Resistance for CrTiAIN Composite Coatings Deposited on Piston Rings

In this paper, the CrTiA1N composite coatings are deposited on piston material of 65 Mn steel substrate by multi-ion plating technology with Cr target and TiAl target, and the hot corrosion resistance at 800 ℃ of Cr, CrN and CrTiAlN composite coatings are compared. The surface oxide film of samples are observed and analyzed by SEM, EDS and XRD. The results indicate that CrTiAlN composite coatings have excellent high temperature corrosion resistance at 800 ℃ , which is caused by oxygen diffusion inward coatings. The Cr in CrTiA1N composite coatings is selectively oxidized, and the Cr2O3 is formed firstly. The structure of oxidation zone of CrTiAlN coatings from outside to inside is Cr2O3,Al2O3 ＋ TiO2, （Cr,Ti,Al） N. The Cr2O3 oxidation could prevent oxygen element diffusing in the coating and reduce the rate of hot corrosion.