C/C-SiC:W/Cu复合涂层的制备和性能

C/C-SiC:Preparation and Properties of W/Cu Composite Coatings

为了提高C/C-SiC复合材料的耐烧蚀性能,改善W涂层的脆性,通过包覆法制备了W/Cu复合粉末,在C/C-SiC复合材料表面通过大气等离子喷涂技术(APS)制备了W涂层、W/Cu复合涂层,研究了不同W/Cu质量比(10∶0.5、10∶1、10∶1.5)对复合涂层的微观结构、显微硬度、耐烧蚀、抗冲刷性能的影响。结果表明,大气等离子喷涂制备的W/Cu复合涂层会形成特殊的Cu/W/Cu/W交替结构,随着Cu的增加,涂层表面夹生W颗粒增多,W/Cu复合涂层的显微硬度降低,最高下降幅度为45%,但W涂层脆性得到明显改善,抗冲刷性能明显增强。在热流密度为4200 kW/m^(2)的氧乙炔火焰考核60 s的过程中,W/Cu复合涂层由于Cu的低熔点、高沸点的发汗特性,会吸收大量热量,从而有效降低涂层表面温度,延缓烧蚀,在W/Cu质量比为10∶1时,W/Cu复合涂层烧蚀中心面直径相较于W涂层缩小57.4%,线烧蚀率和质量烧蚀率分别降低45.5%、42%。

In order to improve the ablation resistance of C/C-SiC composites and improve the brittleness of W coatings,W/Cu composite powders were prepared by cladding method,and W coating,W/Cu composite coating were prepared on the surface of C/C-SiC composites by atmosphe-ric plasma spraying technology.The effects of different W/Cu ratios(10∶0.5,10∶1,10∶1.5)on the microstructure,microhardness,ablation resistance and erosion resistance of the composite coatings were investigated.The results show that the W/Cu composite coating prepared by atmospheric plasma spraying will form a special Cu/W/Cu/W alternating structure.The microhardness decreased,with a maximum decrease of 45%,but the brittleness of the W coating was significantly improved,and the erosion resistance was significantly enhanced.In the process of oxyacetylene flame test with heat flux density of 4200 kW/m^(2)for 60 s,the W/Cu composite coating will absorb a lot of heat due to the characteristics of low melting point and high boiling point of Cu,which can effectively reduce the surface temperature of the coating and delay the ablation.When the mass ratio of W/Cu was 10∶1,the diameter of the ablation center surface of the W/Cu composite coating was reduced by 57.4%compared with that of the W coating,and the line ablation rate and mass ablation rate were reduced by 45.5%and 42%,respectively.