Iron and aluminum alloys cannot be welded together.
Aluminum alloy parts and iron parts can be combined by riveting, bonding and bolting.
Reasons why iron and aluminum alloys cannot be welded
When aluminum and iron are melted together, they will form an extremely brittle melting zone, which has no sufficient mechanical strength and toughness, so it has no practical value, so melting welding cannot be used.
However, if brazing is used, neither aluminum nor iron will melt, and only the brazing material will melt.
It can be seen that the two are connected together, but the operating conditions and brazing materials are not easy to manage.
Using metal materials with lower melting point than the base metal as solder, heating the weldment and solder to a temperature higher than the melting point of the solder and lower than the melting temperature of the base metal, wetting the base metal with liquid solder, filling the joint gap and diffusing with the base metal to realize the method of connecting the weldments.
The brazing deformation is small, and the joint is smooth and beautiful.
It is suitable for welding precise, complex and components composed of different materials, such as honeycomb structural plates, turbine blades, cemented carbide cutters and printed circuit boards.
Before brazing, the workpiece must be carefully processed and strictly cleaned to remove oil stain and excessive oxide film and ensure the assembly gap of the interface.
The clearance is generally required to be between 0.01 and 0.1 mm.
Brazing application features
- The brazing heating temperature is low, the joint is smooth and flat, the microstructure and mechanical properties change little, the deformation is small, and the workpiece size is accurate.
- It can weld different metals and materials, and there is no strict limit on the thickness difference of the workpiece.
- Some brazing methods can weld multiple weldments and joints at the same time, with high productivity.
- The brazing equipment is simple and the production investment is low.
- The joint has low strength, poor heat resistance, strict cleaning requirements before welding, and expensive solder.