Laser welding has the energy concentrated, good weld and heat affected zone is small, the advantages of simple operation, suitable for welding materials of various thickness in the airplane has been widely used in the welding of the titanium alloy parts.
As the fourth generation machine making use of the proportion of TC4 titanium alloy by more than 41% of the quality of structure, has become one of the main body material structure of aviation titanium alloy materials.
Laser welding of titanium alloy is easy to produce what defect?
Stomatal pores is harmful to the titanium alloy laser welding, the most common one of the most big defects, it is easy to cause stress concentration, thus reduce the comprehensive performance of weld.
In welding process, the molten pool of the most violent TeTi metal convection, protective gas may be involved in the molten pool, pool due to the internal temperature gradient is great, welding molten pool after rapid solidification, were involved in the protection of the molten pool gas to escape, thus formed in the melt the bottom hole.
Moreover, a welding molten pool of the rapid solidification can make light of molten pool to plasma don't have enough time to escape out of the pool, it with the molten pool in liquid metal solidification at the same time, the final vacuum is formed within the weld porosity.
Crack during laser welding titanium alloy to absorption of nitrogen, oxygen, hydrogen, surrounding air gap and react with the formation of solid solution, which hinder the movement of the dislocation between the grain boundary, and significantly improve the hardness of the weld, but its plasticity will become worse, cause the whole welded joint embrittlement.
Hydrogen gas is high temperature cause the weld and the surrounding area of the main causes of welding cracks after cooling.
The role of hydrogen in titanium alloy is expanding the beta phase area, lower the beta phase transition temperature, and strengthen the beta phase.
But hydrogen effect on the properties of weld comprehensive embodied in heat affected zone delay crack.
Actually hydrogen content of heat affected zone is far higher than that of the fusion zone, this is because the hydrogen as the movement of molten metal in the molten pool is near to the chilling layer, so after cooling heat affected zone will precipitate a lot of TiH2, leading to increased brittleness of heat affected zone.
In addition, low thermal conductivity, titanium alloy welding molten pool and keep the heat to the heat affected zone in the form of heat conduction, the heat affected zone is always maintaining high temperature, so the precipitation hydride volume rapidly expand, leading to large local stress, when the local stress exceeds the yield limit of material can produce crack.
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Metal laser welding equipment 】
Suitable for all kinds of complex welding, the welding of different equipment and 1 mm thick seam welding;
Multi-channel fiber optic mode, welding transfer at the same time;
Mould laser welding equipment 】
Applicable mould industrialized, used for precision mold repair, such as digital products, mobile phones, toys, automobile, motorcycle, mold and other mold manufacturing and molding industry.
Gold and silver jewelry laser welding 】
Mainly used in jewelry, such as electronics, communications, handicrafts and other industries;
Large laser welding 】
Application in automobile body covering parts of compound, such as car door, side wai, window, floor, warehouse, the warehouse before, trunk lid.
Automatic laser welding machine 】
Using numerical control software by moving or rotating workpiece computer control of mechanical system, so as to realize automatic welding 【
The laser spot welder 】
Can be used for jewelry, watches and clocks hairspring, integrated circuit lead all kinds of small, precise welding of heat sensitive parts of the
YAG laser welding machine 】
High density, the structural weld, precise control, high power density, deep and narrow welds, welding seam and beautiful characteristics of laser welding equipment more laser welding titanium alloy laser welding defects