HfC添加对钼钨合金高温等离子烧蚀性能影响及机理分析  

Effects of HfC addition on plasma flame flow ablation resistance of molybdenum-tungsten alloys and its mechanism analysis

作　　者：杨礼林[1,2] 张启富[1] 贺智勇[1] 李晓刚[2] YANG Lilin;ZHANG Qifu;HE Zhiyong;LI Xiaogang(China Iron&Steel Research Institute Group,Beijing 100081,China;Corrosion and Protection Center,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]钢铁研究总院,北京100081 [2]北京科技大学腐蚀与防护中心,北京100083

出　　处：《粉末冶金材料科学与工程》2018年第2期137-146,共10页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51372093)

摘　　要：本文通过等离子烧蚀系统结合扫描电子显微镜(SEM)研究掺杂不同量HfC颗粒对烧结态钼钨合金和轧制态钼钨合金烧蚀性能及烧蚀形貌的影响,同时探讨分析钼钨合金的高温烧蚀机理。结果表明无论是烧结态还是轧制态,HfC的添加都可以明显提高合金的抗烧蚀性能,且轧制态的抗烧蚀性能明显优于烧结态,因为经过轧制后,材料得到致密化,材料内的部分缺陷(如气孔、夹杂)被消除,同时材料内部颗粒由球形变为层片状,颗粒之间的结合力更强。与氧-乙炔烧蚀实验不同,等离子烧蚀实验过程由于使用保护气体,且焰流的冲击力较强,烧蚀过程主要是以热物理-机械剥离烧蚀为主,HfC的掺杂机理主要是其本身具有的高熔点使其作为驻点存在,形成的少量HfO_2覆盖在基体表面,对基体有一定的保护能力,使材料的高温性能得到提高。The plasma ablation system combined with scanning electron microscopy(SEM)in this work were used to investigate the effects of different amounts of HfC particles on ablation performance and ablation morphology of sintered and rolled molybdenum-tungsten(Mo-W)alloys.Also,the high temperature ablation mechanism of the alloys was further discussed.The results show that the addition of HfC can significantly improve the ablation resistance of the alloys,including sintered and rolled alloys.The ablation resistance of the rolled alloys is obviously better than that of the sintered alloys due to the formation of lamellar structure and eliminating the internal defects(such as pores and impurity)after the rolled treatment.Compared with oxyacetylene ablation experiment,the plasma ablation experiment has protective gas along with strong impact force during ablation process.The ablation process is mainly physical and mechanical ablation.HfC doping mechanism is mainly because of its high melting point as a stagnation point.On the other hand,a small amount of HfO2 film formed on the substrate also has protection effect.As a result,high temperature ablation property of Mo-W alloys is increased.

关 键 词：钼钨合金 碳化铪 等离子烧蚀 烧蚀机理与模型 抗烧蚀性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]