热处理对C/C-Cu复合材料钨涂层结构和烧蚀性能的影响

采用等离子喷涂技术,在C/C-Cu复合材料表面制备钨涂层,在真空炉中进行真空热处理。研究的热处理对涂层结构和氧乙炔焰烧蚀性能的影响。结果表明:未热处理的钨涂层与C/C-Cu复合材料结合良好,钨多以扁平颗粒堆叠成膜,颗粒之间有裂纹等缺陷,其物相组成主要是W。热处理后,C/C-Cu复合材料内的铜向钨涂层渗透,涂层更加致密,但基体与涂层之间的孔隙增加、结合较松散,涂层内有WC生成。氧乙炔焰30 s烧蚀实验表明,C/C-Cu复合材料的质量损失率为5.6 mg/s,未热处理的C/C-Cu复合材料钨涂层的抗烧蚀性能好,其质量损失率为0.9 mg/s,但热处理后的C/C-Cu复合材料钨涂层的抗烧蚀性能显著降低,质量损失率达12.0 mg/s。

Effect of heat-treatment on structure of tungsten coating and ablation properties of C/C-Cu composites

Tungsten-coating(W-coating) had been prepared on prepared C/C-Cu composites using plasmatic spraying,the vacuum heat-treatment was carried out at 1 400 ℃ for 1 h with a vacuum furnace,and the structure and 30 seconds’ ablation-testing using oxyacetylene were investigated.The results show that the W-coating without heat-treatment had been piled by many compressed tungsten particles with some little cracks.The XRD patterns indicated that tungsten is the main phase in the coating.After heat-treatment,many cracks in the coating had been filled with the copper from C/C-Cu matrix,which shows an integrated W-Cu coating but existing a loosed bonding interface between the matrix and the coating due to some cracks and micro-holes.The results of ablated testing shown that the mass loss ratio of the composites without coating was 5.6 mg/s,the coated composites without heat-treatment had good ablation-resistance with a mass loss ratio of 0.9 mg/s,but the coated composites with heat-treatment had the highest mass loss ratio of 12.0 mg/s.