Characteristics of Aluminum alloy Welding
1. Strong oxidation capacity. The affinity of aluminum and oxygen is great and easy to form alumina to hinder the good bonding of metals, which has caused slag clamping.
2. Large thermal conductivity and specific heat capacity. Welding uses a heat source with high power or concentrated energy, and sometimes requires preheating.
3. Hot cracking tendency. Aluminum alloy has a linear expansion coefficient twice as large as iron, and when it solidifies, shrinkage is twice as large as iron. In particular, when welding high-strength aluminum alloys, thermal cracks often occur in the brittle temperature range.
4. It is easy to produce porosity aluminum and aluminum alloy liquid molten pool to absorb gas easily.
5. Due to the action of welding heat, the seam area appears to soften. This is particularly severe when welding heat-treatable reinforced aluminum alloys (Duralumin and super altealumin).