Prediction of Transient Temperature Distributions for Laser Welding of Dissimilar Metals

Abstract

Distribution of temperature during the welding process is essential for predicting and realizing some important welding features such as microstructure of the welds, heat-affected zone (HAZ), residual stresses, and their effects. In this paper, a numerical model was developed using COMSOL Multiphysics of dissimilar laser welding (butt joint) of AISI 316L and Ti6Al4V thin sheet of 2.5 mm thickness. A continuous mode (CW) fiber laser heat source of 300W laser power was used for the present study. A time-dependent prediction of temperature distributions was attempted. The heat source was assumed as a Hermit–Gaussian analytical function with a moving velocity of 120 mm/min. Both convective and radiant heat loss and phase change of the materials were considered for the analysis. In addition, variation of temperature-dependent material properties was also considered. The maximum and minimum temperature for the two materials at different times and the temperature in the different penetration depths were also predicted. It was found that the average temperature that can be achieved in the bottom-most surface near the weld line was more than 2400K, which justifies the penetration. Averages of maximum temperatures on the weld line at different times at the laser spot irradiation were identified near 3000K.The temperature fluctuation near the weld line was minimal and decreased more in the traverse direction. Scanning with a displaced laser relative to the interface toward the Ti6Al4V side reduces the maximum temperature at the interface and the HAZ of the 316L side. All of these predictions agree well with the experimental results reported in current literature studies.

Progressive developments and challenges in dissimilar laser welding of steel to various other light alloys (Al/Ti/Mg): A comprehensive review

“…Thus, laser welding brazing has now a relevant approach when the dissimilar metals have larger differences in properties like Steel and Aluminium [ 146 , 147 ]. In a laser welding process of Steel and Ti alloy shows the similar pattern of compressive and Tensile strength and by using copper/vanadium interlayer/Ni powder the stability of the joint has been improved [ 104 , 118 , 148 ]. The difference of melting point of Ti6Al4V and steel is around 200K and for this the difference in the average compressive strength generated in base metals is very nominal.…”

“…The difference of melting point of Ti6Al4V and steel is around 200K and for this the difference in the average compressive strength generated in base metals is very nominal. The tensile stress generated in weld pool region have a higher value than the base metal compressive stress [ 148 ]. In addition, development of thermal model in any FE software for predicting temperature distribution [ 149 ] and residual stress is important and assessment of optimum laser parameters are to be done by using any optimization technique.…”

“…Crack formation of laser welded butt joint of AISI304 and Ti6Al4V can be reduced by using copper deposition technique. Presence of copper in the welding interface makes the joint compatible from different point of views [ 148 , 160 , 161 , 162 , 163 ]. Coating can play different role for different laser welding processed for Steel-Mg dissimilar joint.…”

“…have considered penetration depth as quality control criteria. Laser welding process is an expensive one [ 185 , 186 , 187 ]. Wide range of experiment is not feasible all the time.…”

Influence of Laser Pulse Welding Power on Welding Joints of Zr‐Based Amorphous Alloys

“…[7,8] Laser welding is a common welding method for amorphous alloys. [9,10] It can ensure smaller heat input and faster DOI: 10.1002/crat.202200063 cooling [11,12] and it can effectively inhibit the crystallization of welded joints. Research on laser welding of amorphous alloys has mainly focused on reducing crystallization and the detection of crystallization composition.…”