Nanoparticle-enabled phase control for arc welding of unweldable aluminum alloy 7075

Maximilian Sokoluk,Xiaochun Li,Shuaihang Pan,Chezheng Cao

doi:10.1038/s41467-018-07989-y

Maximilian Sokoluk, Xiaochun Li + Show 2 more

Open Access

https://doi.org/10.1038/s41467-018-07989-y

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Journal: Nature Communications	Publication Date: Jan 9, 2019
Citations: 213	License type: open-access

Affiliation: University of California, Los Angeles

Abstract

Lightweight materials are of paramount importance to reduce energy consumption and emissions in today’s society. For materials to qualify for widespread use in lightweight structural assembly, they must be weldable or joinable, which has been a long-standing issue for high strength aluminum alloys, such as 7075 (AA7075) due to their hot crack susceptibility during fusion welding. Here, we show that AA7075 can be safely arc welded without hot cracks by introducing nanoparticle-enabled phase control during welding. Joints welded with an AA7075 filler rod containing TiC nanoparticles not only exhibit fine globular grains and a modified secondary phase, both which intrinsically eliminate the materials hot crack susceptibility, but moreover show exceptional tensile strength in both as-welded and post-weld heat-treated conditions. This rather simple twist to the filler material of a fusion weld could be generally applied to a wide range of hot crack susceptible materials.

Highlights

Lightweight materials are of paramount importance to reduce energy consumption and emissions in today’s society
While arc welding of AA7075 is still highly desired for airplanes or vehicles, its arc weldability remains as a barrier
The welds showed a ultimate tensile strength of up to 392 MPa in as-welded condition, while reaching up to 551 MPa with post weld heat treatment (PWHT). This suggests that the introduction of a nanotechnology-treated welding rod to arc welding of AA7075 enables fusion welding for structural design of this high-performance alloy for mainstream applications such as electrical vehicles

Summary

Introduction

Lightweight materials are of paramount importance to reduce energy consumption and emissions in today’s society. The welds showed a ultimate tensile strength of up to 392 MPa in as-welded condition, while reaching up to 551 MPa with post weld heat treatment (PWHT) This suggests that the introduction of a nanotechnology-treated welding rod to arc welding of AA7075 enables fusion welding for structural design of this high-performance alloy for mainstream applications such as electrical vehicles. This nanotechnology-treating approach can be readily extended to welding of other hot crack susceptible materials beyond the 2xxx and 7xxx series aluminum alloys

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