为了提高H13钢的抗高温氧化能力,在H13钢表面沉积了一层CrTiAlN薄膜。采用XRD和SEM分析了H13钢氧化前后的相组成及其表、截面形貌。结果表明:涂层为柱状晶结构,主要有三部分组成:里层为Cr结合层,中间为CrN过渡层,外层是CrTiAlN梯度涂层。H13钢在氧化时,在其表面发生了Cr的选择性氧化,但是Cr含量低,未能形成连续的防护层,最终导致基体元素不断地氧化,生成了大量的α-Fe2O3颗粒。CrTiAlN涂层在800℃时具有良好的抗高温氧化性能,涂层氧化时主要是O向里扩散占优势,没有出现裂纹和剥落,而且观察到了“钉扎效应”。900℃时,涂层失效。
CrTiA1N hard coating have been deposited on H13 steel for improving the oxidation resistance by Closed Field Unbalanced Magnetron Sputter Ion Plating(CFUMSIP). The phase components, surface and section morphology of H13 steel before and after oxidation were analyzed by XRD and SEM. The results show that the columnar crystal film possesses three major parts, i. e. , the internal Cr bonding layer, the intermediate CrN transition layer, the external CrTiAIN gradient coating. The selective oxidation of Cr element was found on the surface of uncoated H13 steel, but a continuous protective layer was not formed because of low Cr content, finally a lot of alpha Fe/O3 particles took place on the surface of H13 steel owing to the oxidation of the matrix elements. The CrTiA1N coating has excellent high- temperature oxidation resistance and O element can diffuse much more oxide scales at 800℃, and spallation and cracks were not found during the oxidation. Besides, "pegging effect" was also observed. But the CrTiA1N coating failed at 900℃.