钎焊超薄GH99蜂窝夹层结构力学性能分析

以制造轻量化超薄金属热防护结构为目标，首先采用真空钎焊方式制备了GH99超薄夹层结构；通过光学显微镜及扫描电子显微镜对夹层结构的钎焊界面及母材的微观组织进行了表征；通过万能试验机对夹层结构的界面剥离强度、面内与面外压缩性能进行了测试，并与有限元模拟结果进行对比.结果表明，钎焊前后母材晶粒由退火态孪晶组织转变为等轴组织；钎焊接头主要为Ni(s, s)和Ni₃Si的共晶组织，并伴随部分Cr(Mo, Ni)固溶体、Ni₂Si及NiSi₂相；界面剥离在薄壁面板上失效；夹层结构面内与面外的压缩失效均表现为屈曲失效，模拟结果与试验结果一致.

2022-11 Abstract

In this study, aiming at the fabrication of lightweight ultra-thin metal thermal protection structures, an ultra-thin sandwich structure was fabricated by vacuum brazing. The brazing interface of the sandwich structure and the microstructure of the base metal were characterized by optical microscope and scanning electron microscope. The interfacial peel strength and in-plane/out-plane compression properties of the sandwich structure were tested by a universal testing machine and compared with the finite element simulation results. The results showed that the grains of base metal transform from annealed twin structure to equiaxed structure before and after brazing. The brazing interface is mainly composed of the eutectic structure of Ni(s, s) and Ni₃Si, accompanied by a certain Cr(Mo, Ni) solid solution, Ni₂Si and NiSi₂ phases. The interfacial delamination failure occurred on the thin-walled panel. Both the in-plane and out-of-plane compression failures of the sandwich structure were buckling failures, and the simulation results were consistent with the experimental results.