Preparation of molybdenum/Palladium/Silver layered metal matrix composites. Steps for molybdenum metal foil pretreatment, molybdenum metal surface plating, molybdenum/palladium/palladium plating sample processing annealing, dehydrogenation, molybdenum/layered dehydrogenation annealing sample surface plating silver and palladium and molybdenum palladium/silver plating sample pressurized annealing, molybdenum palladium/silver layer metal matrix composite section morphology scanning electron microscope and tensile strength of resistance spot welding test. The molybdenum/Palladium and palladium/silver interfaces are diffused, so as to realize metallurgical bonding on the molybdenum/Palladium and palladium/silver interfaces, and obtain the molybdenum/Palladium/silver layered metal matrix composite with good weldability and high interfacial bonding strength. The welding tensile strength of the composite is 416 g force during single point resistance spot welding with solar cells.
Molybdenum and molybdenum alloy have excellent heat resistance, high temperature mechanical properties, low thermal expansion coefficient and high thermal conductivity. The low coefficient of thermal expansion and high coefficient of thermal conductivity make molybdenum and molybdenum alloy very resistant to impact, and the thermal response of the structure is very low. In addition, molybdenum is not ferromagnetic. Because of these characteristics, molybdenum and molybdenum alloy have been widely used in aerospace and micro-electronic equipment, such as antennas for space vehicles, radar magnetron resonator blades, etc.
Platinum has strong chemical stability and oxidation resistance, but platinum is too expensive to produce molybdenum/platinum/silver layered composites and use in space vehicles. Because they are both platinum group metals with similar properties, and molybdenum has a high solubility in palladium (the solubility of molybdenum in palladium reaches about 46% ATM at 1600° C, and the solubility of molybdenum in palladium reaches about 20% ATM at room temperature), it is difficult to form brittle metallic intermetallic compounds between molybdenum and palladium at room temperature. At the same time, pd and Ag alloying can produce discontinuous dissolubilization between the components. Therefore, we try to use Pd instead of platinum as the interlayer metal to prepare lamellar composites, namely mo/Pd/Ag lamellar composites.
The invention relates to a preparation process of molybdenum/Palladium/silver layered metal matrix composite, which utilizes electroplating + multi-channel annealing to realize metal interface alloying and metallurgical bonding. At the same time, increase the dehydrogenation annealing process to solve the problem of palladium metal hydrogen absorption, adopting pressurized annealing solution molybdenum/palladium coefficient of thermal expansion differences lead to problems in terms of interface damage, take off a layer, the preparation of the molybdenum palladium/silver layer metal matrix composites, and meet the performance requirements, improve the molybdenum metal weldability and conductivity, The resistance spot welding strength of the mo/Pd/Ag layered metal matrix composites with space gaas solar cells meets the requirements of national military standard GJB2602-1996, and it can be used to fabricate interconnecting solar cell arrays.
