Process and device for coating silver on molybdenum foil used for solar cell paddle of aerospace aircraft

Abstract

The invention relates to a silver electroplating technology for molybdenum foils used for panel substrate interconnecting flakes of solar cells of a space craft. The technology comprises the steps of molybdenum foils buffing and degreasing treatment, acid cleaning activation treatment, silver metal plasma injection, high temperature annealing treatment, silver leaching treatment, silver electroplating, EDS testing on the constituents of an electroplated layer, shape and morphology SEM observation, passivation for the electroplated molybdenum foils, and testing on the conductibility and the weldability of the electroplated molybdenum foils. The vacuum metal plasma injection technology provided by the invention comprises the following steps: injecting metallic elements as per certain energy and dosage into the molybdenum foil interconnecting flake material processed by buffing, degreasing treatment and acid cleaning activation treatment; carrying out silver leaching treatment after vacuum high temperature annealing; and carrying out non-cyanide silver electroplating so as to achieve a silver plating layer on the molybdenum foils, which is characterized by seamlessness, fine and round crystal grains and dense structure. The passivation treatment for the electroplated molybdenum foils gives the silver plating layer the ability to prevent the silver plating layer from being corroded by sulfide. Meanwhile, the conductibility and the weldability of electroplated aluminum foils are greatly improved without being affected by the passivation treatment.

Description

technical field [0001] The invention relates to material surface treatment technology, in particular to a molybdenum foil silver-plating process and device for interconnecting sheets of solar battery sails of aerospace vehicles, specifically a new technology for silver-plating molybdenum foils for interconnecting sheets of solar battery sails of aerospace vehicles . Background technique [0002] Molybdenum and molybdenum alloys are high temperature resistant materials that can maintain high strength at high temperatures. At the same time, it also has high thermal conductivity and low thermal expansion coefficient, and has good thermal shock resistance. The material is also very conductive and wear-resistant. Due to the above advantages, molybdenum and molybdenum alloys are widely used in the field of aerospace, including molybdenum foil used in solar array interconnects of aerospace vehicles (satellites, spacecraft and space stations). However, the solderability of molybd...

AI Technical Summary

Problems solved by technology

At the same time, it is very difficult to form an alloy (solid solution) between molybdenum and silver. The reason is that the solubility of molybdenum in silver is very small. At 1600 ° C, the solubility of molybdenum in silver is only about 5%. AgMO30, AgMo50, AgMo65 currently on the market Alloys such as AgMo75 and AgMo75 are manufactured by high-temperature sintering of powder metallurgy

Therefore, it is more difficult to electroplate silver on the surface of molybdenum, direct silver plating often does not adhere firmly, and the quality of the coating is poor

The solution to the difficulty of molybdenum electroplating silver is generally to use pre-plating or impact plating to plate a thin layer of metal (such as chromium, nickel, gold, rhodium, platinum, etc.) on the surface, and then continue electroplating after high-temperature heat treatment. Fussy, poor combination of silver plating and molybdenum foil

In addition, it has been reported in the literature that pre-plating nickel will adversely affect the conductivity, while gold, rhodium, and platinum will also increase the cost.

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