scholarly journals Microstructural Characterization and Mechanical Properties of Laser Beam-Welded Dissimilar Joints between A6000 Aluminum Alloy and Galvanized Steel

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 543
Author(s):  
Nkopane Angelina Ramaphoko ◽  
Samuel Skhosane ◽  
Nthabiseng Maledi
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Laser Beam ◽  
Laser Welding ◽  
Heat Input ◽  
Welding Process ◽  
Galvanized Steel ◽  
Vehicle Body ◽  
Welding Parameters ◽  
Dissimilar Joints

This paper presents the laser beam welding process of a lap joint between galvanized steel (Z225) and an aluminum alloy (A6000) from an IPG fiber laser. Welding of steel to aluminum has become popular in the automotive industry as a means of reducing the total vehicle body mass. This approach reduces fuel consumption and, ultimately, carbon emissions. Laser welding parameters used to control heat input for the study were laser power ranging between 800 and 1200 W, as well as laser welding speeds between 2 and 4 m/min. Distinct features of the dissimilar joints were microscopically examined. The SEM-EDS technique was employed to study the intermetallic phases along the Fe-Al interface. The outcome revealed the presence of “needle-like phases” and “island-shaped phases” at high heat inputs. Traces of both Fe2Al5 and FeAl3 phases were detected. For low heat input, there was evidence of insufficient fusion. Weld width was influenced by welding parameters and increased with an increase in heat input. Mechanical properties of the joints indicated that the microhardness values of the weld joints were higher than those of both base metals. The maximum tensile shear strength obtained was 1.79 kN for a sample produced at 1200 W and 3 m/min.

Influence of Heat Input on Mechanical Properties and Microstructure of Laser Welded Dissimilar Galvanized Steel-Aluminum Joints

2018 ◽  
Author(s):  
Celalettin Yuce ◽  
Fatih Karpat ◽  
Nurettin Yavuz
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Penetration Depth ◽  
Heat Input ◽  
Lap Joints ◽  
Galvanized Steel ◽  
Tensile Shear ◽  
Fiber Laser Welding ◽  
Dissimilar Joints ◽  
Weld Width

The hybrid structures of aluminum-steel have been increasingly used for body-in-white constructions in order to reduce weight and green gas emissions. Obtaining acceptable joints between steel and aluminum required a better understanding of welding metallurgy and their effects on the resultant mechanical properties as well as the microstructure of the joints. In this research, the fiber laser welding of zero-gap galvanized steel and aluminum alloy in an overlapped configuration was carried out. The influence of heat input on the weld bead dimension, microstructural and mechanical properties of the joints was studied. A detailed study was conducted on the effects of the heat input on the penetration depth, weld width and microstructure of the laser welded dissimilar joints by means of an optical microscopy. A scanning electron microscopy with energy dispersive spectroscopy was carried out to determine the atomic percent of the elements for intermetallic compounds (IMC) occurred at the interface of the aluminum and steel. Microhardness measurement and tensile shear tests were conducted to evaluate the mechanical properties of the galvanized steel to aluminum lap joints. The experimental results showed that the penetration depth and weld width increased with the increase of heat input level. However, in order to limit IMC layer thickness and hardness at the surface of the weld seam and aluminum alloy, iron to aluminum dilution should be restricted by limiting the penetration depth. At lower heat input levels, less brittle IMC formation was formed. Consequently, with limited penetration depths at low heat input levels, up to 520 N tensile shear load achieved, with failures located in the interface of the joints.

Optimization for Laser Welding Fillet Joint Based on Response Surface Method

2011 ◽  
Vol 211-212 ◽  
pp. 1110-1114
Author(s):  
Xiao Yun Zhang ◽  
Yan Song Zhang
Keyword(s):  
Laser Welding ◽  
Response Surface ◽  
Weld Seam ◽  
Welding Process ◽  
Galvanized Steel ◽  
Plant Production ◽  
Welding Parameters ◽  
Technical Instructions ◽  
Fillet Joint ◽  
Laser Welding Process

The wide use of galvanized steel in automobile manufacturing brings much challenge to the roof to body-side laser welding process. Fillet joint is an effective way to solve this problem such as pore in laser welding process. However, there is little research on this type of complicated joint process. Focused on this problem, take metallographic size of weld seam as the weld quality criteria, response surface methodology (RSM) is used to study the influence of laser welding parameters on weld seam quality. Finally, the optimum welding parameters are concluded to give technical instructions for the plant production.

Study on Quality Control of the Laser Welding Joint

2013 ◽  
Vol 442 ◽  
pp. 276-281
Author(s):  
Qiang Wu ◽  
Lan Ying Xu
Keyword(s):  
Laser Welding ◽  
Salt Water ◽  
Harmful Effect ◽  
Welding Process ◽  
High Strength ◽  
Galvanized Steel ◽  
Welding Parameters ◽  
Test Results ◽  
Welding Joint ◽  
Corrosion Rates

During laser welding process of high-strength galvanized steel, adopting guiding arc plate and the connecting arc plate can avoid harmful effect resulted in unstable melting width. The galvanized layer protecting joint is inevitably lost by having been burned, which affects stain resistance of welding joint. So salt water with the concentration of 3% is used in the corrosion test for the samples welded under different laser parameters, mass variation and metallographic microscopes are gained after joint being corroded. The test results indicate that the corrosion rates of the joint are different under different welding parameters during laser welding of high-strength galvanized steel; their average corrosion rates are coincident with that of base metal and laser welding technology hardly effect corrosion resistance of the joint.

Interactions of the process parameters and mechanical properties of laser butt welds in thin high strength low alloy steel plates

2020 ◽  
Vol 234 (5) ◽  
pp. 665-680 ◽  
Author(s):  
Patricio Gustavo Riofrío ◽  
Carlos Alexandre Capela ◽  
José AM Ferreira ◽  
Amilcar Ramalho
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Laser Welding ◽  
Alloy Steel ◽  
Heat Input ◽  
High Strength ◽  
Welding Parameters ◽  
Bead Geometry ◽  
Low Alloy Steel ◽  
Weld Bead Geometry

High strength low alloy steels subjected to the thermomechanical control process present excellent strength–toughness combination, high strength/weight ratio, and weldability. Therefore, they are widely used in structural components, such as pressure vessels, oil/gas transportation pipes, lifting equipment, vehicles, shipbuilding and offshore industries, and in the automotive industry where low thickness (0.8–3 mm thickness) is of great importance. Usually, these steels are welded by conventional gas metal arc welding, which creates wide heat-affected zones, large residual stresses, and distortion in the welded parts. Laser welding is nowadays an alternative process to weld high strength low alloy steel parts due to its advantages. The aim of this work is to understand the effect of process parameters on defects, weld bead geometry, microstructure, and mechanical properties, namely hardness and tensile strength. We identify the main laser welding parameters and their influence on the weld bead geometry and defects, for a 3 mm thick high strength low alloy steel welded under a maximum power of 2 kW. A cross section of the weld seam was optimized achieving a good geometry without porosity. The threshold value of the heat input to achieve complete penetration was determined for different focus diameters. The microstructure, size, and hardness of the heat-affected zone and of the fusion zone are strongly influenced by the heat input. The values of the tensile strength achieved in butt welds were close to the base metal by an appropriate selection of the laser welding parameters and the heat input.

Research on Laser Micro Welding of an Aluminum Alloy Pressure Sensor

2015 ◽  
Vol 1114 ◽  
pp. 160-165 ◽  
Author(s):  
Robert Ciobanu ◽  
Octavian Donţu ◽  
Daniel Besnea ◽  
Victor Constantin ◽  
Doina Cioboata
Keyword(s):  
Aluminum Alloy ◽  
Laser Welding ◽  
Surrounding Medium ◽  
Laser Beam Welding ◽  
Pressure Sensors ◽  
Welding Process ◽  
Welding Parameters ◽  
Surface Pretreatment ◽  
Very High

This paper presents in detail the laser welding of a new mechatronic component belonging to the pressure sensors made ​​by aluminum alloy AW2007. Due to very high reflectivity of aluminum alloys, fast oxidation, the absorption of gases from the surrounding medium, special difficulties arise at laser beam welding and most situations require appropriate surface pretreatment. Given these issues, the paper present an experimental study on the influence of welding parameters on the seam quality for the aluminum alloy AW2007. In addition of the study regarding the influence of welding parameters, such as, laser power, welding speed, we conducted an analysis on the influence of the initial temperature of the material on the quality of the weld. Besides these aspects the paper presents a constructive solution for a device used to optimize the laser welding process of the sensor.

scholarly journals Microstructural Characterization and Mechanical Properties of Fiber Laser Welded CP-Ti and Ti-6Al-4V Similar and Dissimilar Joints

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 747 ◽  
Author(s):  
Alireza Abdollahi ◽  
Ahmed Shaheer Ahnaf Huda ◽  
Abu Syed Kabir
Keyword(s):  
Mechanical Properties ◽  
Fiber Laser ◽  
Welding Speed ◽  
Heat Input ◽  
Laser Power ◽  
Pure Titanium ◽  
Microstructural Characterization ◽  
Welding Parameters ◽  
Dissimilar Joints ◽  
Cp Ti

In this research, the microstructures and mechanical properties of similar and dissimilar autogenous joints of 3 mm thick commercially pure titanium (CP-Ti) and Ti-6Al-4V welded by ytterbium fiber laser (Yb:YAG) were investigated. Two sets of laser power and welding speed were selected in such a way that the heat input remained constant. Microstructural characterization of the joints was investigated by an optical microscope, and mechanical properties were determined by hardness and tensile tests. The only defects found were porosity and underfill, and no signs of lack of penetration and solidification cracks were observed in any of the joints. Microstructural evaluation of the fusion zone (FZ) showed that in similar Ti-6Al-4V joint, a supersaturated nonequilibrium α′ martensite was formed due to rapid cooling associated with laser welding. In similar CP-Ti, coarse equiaxed grains were observed in the FZ. Unlike the similar joints, a clear interface was observed between the heat-affected zone (HAZ) and the FZ in both the CP-Ti and Ti-6Al-4V sides in dissimilar joints. Among all the joints with different weld parameters, similar Ti-6Al-4V showed the highest strength and the lowest ductility. In similar CP-Ti and dissimilar joints, fractures took place in the CP-Ti base metal, but all the Ti-6Al-4V similar joints failed in the FZ. Significant changes in the strength and hardness with varying laser power and welding speed implied that the mechanical properties of the weld fusion zones were not entirely governed by the heat input but were also affected by individual welding parameters.

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