Analysis of microstructure and mechanical properties of titanium-aluminum dissimilar metal laser fusion brazing joints
Using the YLS-4000 fiber laser,butt welding of TC4 titanium alloy and 5052 aluminum al-loy is performed by offsetting the laser towards the aluminum alloy to achieve laser autogenous welding of dissimilar titanium-aluminum metals.Optical microscopy,scanning electron microscopy,and ten-sile testing are employed to analyze the effects of laser offset and welding speed on the microstructure and mechanical properties of the welded joints.The experimental results indicate that an intermetallic compound layer,averaging a few micrometers in thickness,formed at the joint interface.This layer comprises TiAl on the titanium side and TiAl3 on the aluminum side.Under the conditions of a laser power of 3000 W,defocus of 0,laser offset of 0.6 mm towards the aluminum side,and a welding speed of 3.0 m/min,the maximum tensile strength of the joint reaches 175.4 MPa.The fracture tough-ness of the Ti/Al joint decreases as the thickness of the intermetallic compound layer increases.The maximum thickness of the compound layer is 6.54 μm,at which point the fracture toughness of the joint is the lowest,measuring 10.778 MPa∙m1/2.
万方数据
维普
