Classification Of Weldability Characteristics
Aluminum alloy fusion welding has the following difficulties and features:
(1) The affinity of aluminum and oxygen is large, so there is always a layer of refractory alumina film on the surface of aluminum and aluminum alloy far exceeding the melting point of aluminum, which is insoluble in metal and hinders the wetting of the molten filler metal. The oxide film should be removed or destroyed during soldering or soldering.
(2) When welding, the weldability of aluminum alloy is first reflected in crack resistance. Adding alloying elements such as copper, manganese, silicon, magnesium and zinc to aluminum can obtain alloys with different properties, and various alloying elements have different effects on welding cracks of aluminum alloy.
(3) The solid and liquid color of aluminum alloys are not easy to distinguish, and it is difficult to control the temperature of the molten pool during welding operations.
(4) After welding, the weld is prone to generate air holes, and the welded joint area is prone to softening.
For the welding of aluminum alloys, a variety of different welding methods can be used. The relative weldability of some aluminum alloys listed in Table 1.4.
The development of modern science and technology has promoted the advancement of aluminum alloy welding technology. The range of weldable aluminum alloy materials has gradually expanded, and now it can not only successfully weld non-heat-treated reinforced aluminum alloys, but also solves the traditional aerospace and military industries, and gradually expands into various fields of national economic production and people's lives.