钨渗铜样件烧蚀裂纹产生机理探讨

Discussion on the mechanism of ablation cracks in tungsten-infiltrated copper specimen

以烧蚀后的钨渗铜样件(牌号W-7Cu)为研究对象,针对特定环境条件下烧蚀试验后钨渗铜样件表面裂纹进行了形貌特征分析并对裂纹产生的机理进行了探讨。表面形貌及能谱分析结果表明,3000℃高温环境试验后,表面存在Cu析出且在高温粒子冲刷后留下烧蚀坑,嵌入基体的颗粒中含有大量C、O、Al等元素;物相分析表明,烧蚀产物的主要相为WC、W6C2.54脆性相,推测Cu相挥发后铜基体上形成连通孔隙,推进剂或者环境中的C进入钨骨架孔隙中,与钨渗铜件中的W形成碳化钨脆性相导致烧蚀过程中形成小裂纹继而分层剥离,是烧蚀裂纹产生的主要原因。

Taking the ablated tungsten-infiltrated copper sample(brand W-7Cu)as the research object,the surface crack morphology characteristics of the material after ablation test were analyzed,the macro-micro progressive test and analysis were carried out,and the mechanism of cracks was discussed.The results of surface morphology and energy spectrum analysis show that there is Cu precipitation on the surface after the test at 3000℃,and ablation pits are left after the high temperature particles are washed away,and the particles embedded in the matrix contain a lot of elements such as C,O and Al.The phase analysis shows that the main phases of ablation products are WC and W6C2.54 brittle phases,and it is speculated that Cu phase volatilizes to form connected pores.Propellant or C in the environment enters the pores of tungsten skeleton and forms tungsten carbide brittle phase with W in tungsten infiltrated copper parts,which leads to small cracks and delamination during ablation,which is the main reason for cracks.