HfC添加对钼钨合金高温等离子烧蚀性能影响及机理分析

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.