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为了提高炭/炭(C/C)复合材料的耐烧蚀性能,以孔隙率为38%的C/C复合材料为坯体,Zr-Cu混合粉末为熔渗剂,采用反应熔渗法制备了ZrC-Cu-C/C复合材料。通过氧-乙炔焰烧蚀实验,研究了熔渗剂成分对复合材料高温耐烧蚀性能的影响。利用XRD、SEM和EDS对烧蚀前后ZrC-Cu-C/C复合材料的相组成和微观结构进行了分析。结果表明:ZrC-Cu-C/C复合材料烧蚀前主要存在C、ZrC和Cu相,有微量Zr残余;烧蚀20s后表面主要存在炭基体、ZrO_2、CuO、Cu_2O及残余的ZrC和Cu。随熔渗剂中Zr含量增加,复合材料的线烧蚀率和质量烧蚀率均呈现先减小后增大的趋势,以60%Zr-Cu(质量分数)为熔渗剂制备的ZrC-Cu-C/C复合材料的抗烧蚀性能最佳,其线烧蚀率和质量烧蚀率分别为0.0018mm·s~(-1)和0.0013g·s~(-1)。ZrC-Cu-C/C复合材料的烧蚀机制为以C的升华、ZrO_2的熔化及Cu的蒸发和汽化为主的热物理烧蚀、ZrC和C氧化的热化学烧蚀以及高压热流冲刷引起的机械剥蚀的综合作用。
In order to improve the ablation resistance of C / C composites, the C / C composites with a porosity of 38% were used as the green body and the Zr-Cu mixed powders were infiltrated by infiltration. ZrC-Cu-C / C composites. Through the oxy-acetylene flame ablation experiment, the effects of infiltrant composition on ablation resistance of composite at high temperature were studied. The phase composition and microstructure of ZrC-Cu-C / C composites before and after ablation were analyzed by XRD, SEM and EDS. The results show that there are mainly C, ZrC and Cu phases before ZrC-Cu-C / C composites with a small amount of Zr residue. After 20 seconds of ablation, there are mainly carbon matrix, ZrO_2, CuO, Cu_2O and residual ZrC and Cu . With the increase of the Zr content in the infiltrant, the wire ablation rate and mass ablation rate of the composites all decrease first and then increase, the ZrC- The ablation resistance of Cu-C / C composites is the best, and the ablation rate and mass ablation rate are 0.0018mm · s -1 and 0.0013g · s -1, respectively. The ablation mechanisms of ZrC-Cu-C / C composites are thermophysical ablation mainly including sublimation of C, melting of ZrO 2 and Cu evaporation and vaporization, thermochemical ablation of ZrC and C oxidation, and erosion of high pressure heat flux The combined effect of mechanical erosion.