摘要
目前,对TiAlSiN薄膜在800℃以上的抗高温氧化性研究较少。通过磁控溅射优化工艺在W18Cr4V高速钢基体上制备不同Si含量的TiAlSiN硬质薄膜,针对硬度最高的典型薄膜试样[Si含量为16.49%(原子分数)],分别在800℃和1 000℃下进行保温1 h的大气热处理。利用SEM、EDS、XRD和纳米压痕仪对薄膜的形貌、成分、相结构和硬度等进行表征。结果表明:随着Si含量从无到有并增加,薄膜硬度呈现上升-下降-上升-陡降-缓降的趋势,当Si含量为16.48%(原子分数)时,薄膜硬度达到最大值26.43 GPa,薄膜由(Ti,Al)N和Si_3N_4构成复合结构;经800℃大气热处理后薄膜表面生成大量的Al_2O_3,同未热处理试样相比,表面较为致密和平整;经1 000℃大气热处理后,膜层中的Ti、Al和Si元素外扩散形成TiO_2和Ti_2O_3等多种氧化产物,导致薄膜表面凹凸不平,甚至剥落,薄膜硬度和抗氧化效果明显下降。
TiAlSiN hard coalings with different Si content were deposited on W18Cr4 V high-speed steel(HSS) by magnetron sputtering technology.Typical coatings with the optimal hardness were heat-treated at 800℃ and 1 000℃ for 1 h in air.The morphology,composition,phase structure and hardness of TiAlSiN coalings were characterized by scanning electron microscopy,which equipped with EDS,X-ray diffraction and nano-indentation.Results showed that the hardness of coatings followed a trend of risefall-rise-fall rapidly-fall slowly,as the Si content increased.When the Si content was 16.48%,the coating presented the highest hardness of 26.43 GPa,and it was composed of(Ti,A1)N and Si_3N_4 as complex structure.Otherwise,a lot of Al_2O_3 appeared after atmosphere heat treatment at 800℃.Compared with the original sample,the surface became dense and smooth.After atmosphere heat treatment at 1 000℃,the Ti,Al and Si element spread out for the formation of TiO_2 and Ti_2O_3,which made the surface irregularity and even dropped,so that the oxidation resistance of coating declined significantly.
出处
《材料保护》
CAS
CSCD
北大核心
2016年第8期5-7,11,共4页
Materials Protection
