C/C复合材料基TaC涂层低功率激光烧蚀特征  

Characteristics of TaC coatings ablated by low power laser

作　　者：李国栋[1] 熊翔[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2005年第3期155-159,共5页Materials Science and Engineering of Powder Metallurgy

基　　金：国家高新技术研究发展计划资助项目(2002AA305207);湖南省自然科学基金(03JJY3073);湖北省教育厅基金资助项目(D200525004)

摘　　要：为研究TaC涂层的高温烧蚀特征和机理,用低功率激光仪对TaC涂层进行了不同时间的烧蚀试验,并用XRD,SEM等观测了该涂层在空气中的氧化与烧蚀过程。结果表明:在大气环境下激光烧蚀的开始阶段是TaC涂层的分解与游离碳向表面扩散,随即氧化生成含碳、氧、钽的熔体,随着时间的延长熔体氧化为低价的钽氧化物,最后生成Ta2O5;熔体在冷却过程中析出Ta2O5针状晶体。在熔体与TaC之间存在1～2μm由细小的晶体和孔隙组成的扩散过渡层,过渡层由碳、氧、钽组成。To study the ablative characteristics and mechanism of TaC coatings at high temperature, ablation experiments were conducted by low power laser with different time; and the oxydation and ablation processes of the coatings were observed/measured by using XRD, SEM, etc. The results show that the TaC coating was discomposed into Ta and the dissociative carbon was diffused to the surface of TaC coating at the first stage of laser ablation; then thouse were oxidized and converted into the melt with Ta, C, O under atmosphere environment; the melt was oxidized to Ta_2O_3 as time increasing and changed into Ta_2O_5 at last. The melt crystallized out acicular Ta_2O_5 whisker during cooling. There was a diffuse transition layer with small crystals and holes between the melt and the TaC coating, which involves Ta, C and O, about 12μm in thickness.

关 键 词：TAC 涂层 激光烧蚀 氧化 烧蚀机理 

分 类 号：V257[一般工业技术—材料科学与工程]