Influence of the Overlapping Factor and Welding Speed on T-Joint Welding of Ti6Al4V and Inconel 600 Using Low-Power Fiber Laser

Shamini Janasekaran,Ai Tan,Farazila Yusof,Mohd Abdul Shukor

doi:10.3390/met6060134

Abstract

Double-sided laser beam welding of skin-stringer joints is an established method for many applications. However, in certain cases with limited accessibility, single-sided laser beam joining is considered. In the present study, single-sided welding of titanium alloy Ti6Al4V and nickel-based alloy Inconel 600 in a T-joint configuration was carried out using continuous-wave (CW), low-power Ytterbium (Yb)-fiber laser. The influence of the overlapping factor and welding speed of the laser beam on weld morphology and properties was investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. XRD analysis revealed the presence of intermetallic layers containing NiTi and NiTi2 at the skin-stringer joint. The strength of the joints was evaluated using pull testing, while the hardness of the joints was analyzed using Vickers hardness measurement at the base metal (BM), fusion zone (FZ) and heat-affected zone (HAZ). The results showed that the highest force needed to break the samples apart was approximately 150 N at a laser welding power of 250 W, welding speed of 40 mm/s and overlapping factor of 50%. During low-power single-sided laser welding, the properties of the T-joints were affected by the overlapping factor and laser welding speed.

Highlights

Titanium and nickel-based alloys are generally difficult-to-machine and hard-to-cut materials.Nickel-based alloys, such as Inconel 600, have broad operational temperature, which makes them suitable for high-temperature processes owing to their thermal fatigue resistance [1]
The results showed that an asymmetric weld shape formed and brittle intermetallic compounds of NiTi2 and Ni3 Ti were obtained in the macroscopic shape of the weld pool [12]
Single-sided laser welding was successfully performed on thin sheets of Ti6Al4V and Inconel

Summary

Introduction

Titanium and nickel-based alloys are generally difficult-to-machine and hard-to-cut materials.Nickel-based alloys, such as Inconel 600, have broad operational temperature, which makes them suitable for high-temperature processes owing to their thermal fatigue resistance [1]. Ni-based super alloys, such as Inconel 718, Inconel 628 and Inconel 600, are extensively employed in the aerospace industry because of their superior mechanical properties and excellent oxidation resistance at elevated temperatures. They are suitable to be manufactured as components in high-temperature regions of aero engines and gas turbines [2]. In the automotive field, manufacturing lighter racing car parts has prompted great interest in achieving rapid movement In this context, titanium (Ti) alloy and nickel (Ni) super alloys offer the advantage of reduced race car weight through the custom design of headers and shafts [5]

Methods

Discussion

Conclusion