Laser Butt Welding of Thin Ti6Al4V Sheets: Effects of Welding Parameters

Peter Omoniyi,Tien-Chien Jen,Nana Arthur,Togo Shinonaga,Samuel Skhosane,Rasheedat Mahamood,Yasuhiro Okamoto,Esther Akinlabi,Martin Maina,Sisa Pityana

doi:10.3390/jcs5090246

Abstract

Titanium and its alloys, particularly Ti6Al4V, which is widely utilized in the marine and aerospace industries, have played a vital role in different manufacturing industries. An efficient and cost-effective way of joining this metal is by laser welding. The effect of laser power and welding speed on the tensile, microhardness, and microstructure of Ti6Al4V alloy is investigated in this paper. Results show that the microhardness is highest at the fusion zone and reduces towards the base metal. The microstructure at the fusion zone shows a transformed needle-like lamellar α phase, with a martensitic α’ phase observed within the heat affected zone. Results of tensile tests show an improved tensile strength compared to the base metal.

Highlights

The aerospace, marine, chemical, and automobile industries have found titanium and its alloys highly useful due to their lightweight and high corrosion resistivity [1,2,3]
Hong and Shin [9] found that the speed at which Ti6Al4V is welded using a laser affects the α’ martensite formation within the weld zone, which in turn increases the hardness within this zone
The similar to the observation by FZ, which consists of structure images were captured at the fusion zone (FZ), heat affected zone (HAZ), and base metal

Summary

Introduction

The aerospace, marine, chemical, and automobile industries have found titanium and its alloys highly useful due to their lightweight and high corrosion resistivity [1,2,3]. Aluminum Garnet (Nd: YAG) laser as reported by Cao and Jahazi [6] These high welding speeds might have formed a higher amount of martensitic microstructure within the weld zone (WZ). A situation of low power input at high welding speed resulted in a lack of penetration. Due to these defects, microstructure deficiencies, and selection of the proper welding parameter combination, this research examines the effect of laser power and welding speed on 1-mm-thick Ti6Al4V sheets. Microstructure deficiencies, and selection of the proper welding parameter combination, this research examines the effect of laser power and welding speed on 1-mm-thick Ti6Al4V sheets It adopts the L9(32 ) Taguchi for the design of the experiment. The parameters used were carefully selected to avoid the parameter combinations that do not give full penetration as reported by previous works of literature

Materials and Methods

Figures and

Tensile Properties

Conclusions

Findings

There reduction in ductility for all welded samples because the α