Aluminum Alloy Chassis Vacuum Brazing

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SIMUWU has extensive experience in the field of vacuum brazing, and has long been committed to selling aluminum alloy brazing equipment. Among them, in the field of aviation, aluminum alloy brazing technology is the most widely used. This paper takes the aluminum alloy chassis for aviation as an example for the process reference of vacuum brazing.

Aluminum alloy electronic chassis is widely used in the field of airborne electronic equipment due to its light and compact structure, high heat transfer efficiency, good adaptability to environmental conditions (such as electromagnetic compatibility, high temperature, vibration, strong electromagnetic interference, etc.), and high degree of standardization. The aluminum alloy electronic chassis is mainly used to fix the aluminum alloy parts and brazing materials into a rectangular frame through a specific vacuum brazing process, and then put them into a vacuum brazing furnace for heating and forming. As the core forming process of aluminum alloy electronic chassis, vacuum brazing will directly affect the product quality and even the performance of the entire equipment. This paper takes a typical structure of aluminum alloy electronic chassis as an example to analyze and study its process technology.

Structure and composition:

The typical structure of aluminum alloy electronic chassis is generally composed of panels, side panels, cooling fins, guide rails and reinforcing ribs. Aluminum alloy electronic chassis needs to meet the requirements of heat dissipation, electromagnetic compatibility, corrosion, high temperature, miniaturization, etc., and has a compact structure, high precision of rail insertion and removal, and large difference in plate thickness, etc., which determines the dimensional accuracy and geometric tolerance requirements of electronic chassis. high. The general design requires the coplanarity of the upper and lower guide rails to be 0.2mm, the dimensional tolerance of the guide rail to be 0.3mm, the flatness of the heat dissipation panel to be 0.1mm, the flatness of each surface of the shape to be 0.5mm, and the verticality to be 0.5mm, etc.

Process parameter curve:

The aluminum alloy electronic chassis is formed by vacuum brazing, the widely used material is aluminum alloy 3A21, and the suitable brazing material is BAl87Si11.5Mg1.5

The process curve parameters of vacuum brazing of aluminum alloy electronic chassis fully consider equipment capacity, structural form, material characteristics, etc., and are divided into 4 heating stages and 4 heat preservation stages, the first heating interval is 20min, and the first heat preservation interval is 200 ℃, 20min; The second heating interval is 30 minutes, the second holding interval is 400°C, 40 minutes; the third heating interval is 30 minutes, the third holding interval is 570°C, 40 minutes; the fourth heating interval is 20 minutes, and the fourth holding interval is 615°C, 6 minutes; Cooling ≤100℃ out of the oven.

After mastering the corresponding parameters, it is necessary to select a suitable vacuum furnace for operation. At present, the most suitable product series of SIMUWU is RVB-L low temperature vacuum brazing furnace. It has the characteristics of high temperature accuracy, high vacuum degree and good temperature uniformity in the heating area. It is an ideal equipment for vacuum brazing of aluminum alloy chassis.