How to Weld Extruded Aluminum Flat Bars

How to Weld Extruded Aluminum Flat Bars: A Comprehensive Guide

Introduction

Welding extruded aluminum flat bars requires specialized techniques to create strong, durable, and corrosion-resistant joints. This article provides a detailed walkthrough of the entire welding process, covering preparation, selection of welding methods, and post-weld treatments.

Material Preparation

1. Cleaning: Remove any dirt, oil, or oxidation from the surfaces to be welded using a solvent or wire brush.

2. Mechanical Preparation: If necessary, use a milling machine or grinder to create a bevel or groove on the edges of the bars. This will improve weld penetration and strength.

3. Filler Rod Selection: Choose a filler rod with an aluminum alloy composition that matches or is compatible with the base metal.

Welding Methods

TIG (Tungsten Inert Gas) Welding

1. Electrode Preparation: Sharpen the tungsten electrode to a conical point and clean it thoroughly.

2. Shielding Gas: Use argon as the shielding gas to protect the weld from oxidation.

3. Welding Technique: Hold the torch perpendicular to the workpiece and melt the edges together while feeding the filler rod into the weld pool.

MIG (Metal Inert Gas) Welding

1. Wire Selection: Use an aluminum welding wire with a diameter appropriate for the thickness of the bars.

2. Shielding Gas: Use a mixture of argon and helium as the shielding gas for better weld penetration and reduced spatter.

3. Welding Technique: Feed the wire continuously while melting the edges of the bars together.

Post-Weld Treatments

Heat Treatment

1. Annealing: Heat the weldment to a specific temperature and hold it there for a period of time to soften the metal and improve its ductility.

2. Aging: Heat the weldment to a lower temperature and hold it for a longer period to increase its strength and hardness.

Cleaning

1. Chemical Cleaning: Remove flux residue and other contaminants from the weld surface using a chemical solution.

2. Mechanical Cleaning: Grind or brush the weld to remove any imperfections and smooth the surface.

Conclusion

Welding extruded aluminum flat bars requires a combination of proper preparation, careful selection of welding methods, and thorough post-weld treatments. By following the steps outlined in this article, you can achieve strong, durable, and aesthetically pleasing welds that will meet your specific application requirements.