Microstructure and properties of metallurgical bonding Mo/Pt/Ag laminated metal matrix composites

摘要

The Mo/Pt/Ag laminated metal matrix composites (LMMCs) have been used as interconnected materials of solar cell array of spacecraft at low-Earth orbit (LEO), where the interconnectors are vulnerable to the combined effects of atomic oxygen (AO) and thermal cycles. To enhance its resistance to LEO environment, the metallurgical bonding Mo/Pt/Ag LMMCs was prepared in this work with optimized processing parameters. During the process, the multiple calenderings and annealing at a protecting atmosphere were performed to improve the surface activity of Mo and Pt. Consequently, the expectant metallurgical bonding interfaces of Mo/Pt and Pt/Ag were successfully constructed through the atomic diffusion accelerated by the improvement of surface activity. Additionally, the resulting microstructure of the Mo/Pt interface was confirmed to be composed of MoPt and Mo3Pt alloy phases, and the Pt/Ag interface consisted of distorted and tangled Pt and Ag lattices. Besides, the interfacial type and the orientation relationships of constituent phases were determined. Lastly, the as-obtained Mo/Pt/Ag LMMCs is assessed to have good resistance to thermal fatigue and AO erosion by the thermal cycling and AO exposure experiments.