Microstructure, Corrosion and Mechanical Properties of TiC Particles/Al-5Mg Composite Fillers for Tungsten Arc Welding of 5083 Aluminum Alloy.

Qibo Huang,Xin Tang,Chunxia Wang,Rouyue He

doi:10.3390/ma12183029

Abstract

A semi-solid stir casting mixed multi-pass rolling process was successfully employed to manufacture TiCp/Al-5Mg composite filler wires with different contents of TiC particles. The 5083-H116 aluminum alloys were joined by tungsten inert gas (TIG) using TiCp/Al-5Mg composite weld wires. The microstructure, mechanical properties, fractography and corrosion behavior of the welds were evaluated. The results revealed that TiC particles were distributed in the welds uniformly and effectively refined the primary α-Al grains. The hardness and tensile strength of the welds were improved by increasing the TiC particle content, which could be attributed to the homogeneous distribution of TiC particles and the microstructure in the weld joints. Potentiodynamic polarization testing revealed that the corrosion resistance of the welds also increased with the addition of TiC particle contents. In addition, the stress corrosion cracking (SCC) susceptibility of the welds decreased as micro-TiC particles were introduced into the welds. The electronic structure of the Al/TiC interface was investigated by first principle calculation. The calculation showed that valence electrons tended to be localized in the region of the TiC-Al interface, corresponding to an addition of the overall work function, which hinders the participation of electrons in the composite in corrosion reactions.

Highlights

Aluminum and its alloys have been widely applied in aircraft, marine, aerospace and automotive industries because of their extraordinary properties, for example, light weight, high specific strength, excellent processing properties and corrosion resistance [1]
It is obvious contents of TiC particles produced by semi-solid stir casting and the multi-pass rolling method. It is that the reinforced particles were successfully introduced into the basic alloy through the semi-solid obvious that the reinforced particles were successfully introduced into the basic alloy through the stir casting process
TiCp/Al-5Mg composite filler wires with various contents of TiC particles were successfully fabricated by a semi-solid stir casting mixed multi-pass rolling process

Summary

Introduction

Aluminum and its alloys have been widely applied in aircraft, marine, aerospace and automotive industries because of their extraordinary properties, for example, light weight, high specific strength, excellent processing properties and corrosion resistance [1]. Welding processes play a paramount role in the expanding application of Al and its alloys, and have been considerably investigated in recent years. In TIG welding, there is an electric arc between the base metals and a non-consumable tungsten electrode, which is used for melting and joining filler metals by heating them. The chemical composition of filler metal has a considerable impact on the microstructures and mechanical properties of the TIG weld joints [2,3]. Aluminum matrix composites (AMCs) have become one of the most promising materials owing to their outstanding properties, e.g., low thermal expansion and good wear resistance [4]

Methods

Results

Conclusion