The Study on Mechanical Strength of Titanium-Aluminum Dissimilar Butt Joints by Laser Welding-Brazing Process

Xiongfeng Zhou,Fan Zhang,Ji’An Duan,Shunshun Zhong

doi:10.3390/ma12050712

Xiongfeng Zhou, Fan Zhang + Show 2 more

Open Access

https://doi.org/10.3390/ma12050712

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Journal: Materials	Publication Date: Feb 28, 2019
Citations: 25	License type: CC BY 4.0

Affiliation: Central South University

Abstract

Laser welding–brazing of 5A06 aluminum to Ti6Al4V titanium in a butt configuration was carried out to discuss the influences of welding parameters on dissimilar joint properties. The effects of laser offset, welding speed, and laser power on the spreading length of the molten aluminum liquid, interface fracture zone width (IFZW), fracture roughness, intermetallic compounds (IMCs) thickness, and tensile strength were also investigated. The microstructure and fracture of the joint were also studied. The results show that the tensile strength of the joint is not only influenced by the thickness and type of IMCs, but also influenced by the spreading ability of the aluminum liquid, the fracture area broken at the Ti/fusing zone (FZ) interface, and the relative area of the brittle and ductile fracture in FZ. A dissimilar butt joint with an IMC thickness of 2.79 μm was obtained by adjusting the laser offset, welding speed, and laser power to 500 μm, 11 mm/s and 1130 W, respectively. The maximum tensile strength of the joint was up to 183 MPa, which is equivalent to 83% of the tensile strength of the 5A06 aluminum alloy.

Highlights

In order to meet environmental and economic needs, modern industry has put forward higher requirements for new processes and structures [1]
Because of the low density, low cost, good forming property of the aluminum alloy [2], the excellent erosion resistance and biocompatibility, high temperature resistance, and the strength of the titanium alloy, titanium–aluminum hybrid structures have a wide range of potential applications in automotive, shipbuilding, and aerospace industries [3], which can significantly reduce weight and improve combination properties of the structure, such as corrosion resistance and high temperature resistance [4]
Due to the significant difference in chemical and physical properties, it is difficult for the aluminum alloy and titanium alloy to be perfectly welded together

Summary

Introduction

In order to meet environmental and economic needs, modern industry has put forward higher requirements for new processes and structures [1]. Because of the low density, low cost, good forming property of the aluminum alloy [2], the excellent erosion resistance and biocompatibility, high temperature resistance, and the strength of the titanium alloy, titanium–aluminum hybrid structures have a wide range of potential applications in automotive, shipbuilding, and aerospace industries [3], which can significantly reduce weight and improve combination properties of the structure, such as corrosion resistance and high temperature resistance [4]. Brittle intermetallic compounds (IMCs) such as Ti3 Al, TiAl, TiAl2 , and TiAl3 are formed during the welding process [5]. These compounds have serious adverse effects on the weld quality of the joint because of their high brittleness and hardness. Successful welding of the aluminum alloy and titanium alloy plates requires

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Conclusion