Dimensional Variation Analysis of T-Node Joints Using Aluminum 6063-T52 Extrusion Material in Gas Metal Arc Welding (GMAW) Joining Process

The development of manufacturing processes for joining and assembling of lightweight aluminum vehicles requires detailed process capability studies as well as dimensional variation analysis studies to ensure process controls are in place. These manufacturing processes not only have to provide cycle time viability but also need to maintain or surpass product safety and quality. T-Nodes joint designs are an integral of aluminum architectures based on hybrid designs, i.e those fabricated from mixed aluminum products consisting of castings, stampings and extrusions. The purpose of this study was to find optimum parameters for minimum distortion for the gas metal arc welding (GMAW) of 6063-T52 T-Nodes. The welding factors considered were locators (4-way and 2-way pins verses net surfaces), the welding equiment process factors (power input, pulse frequency, gas flow rate, torch angle and arc intensity), the use of simultaneous welding, and welding sequence order. A partial factorial design of experiment (DOE) was conducted to understand the effects of these factors on T-node joint distortions. A total of 14 points were considered for dimensional distortion measurements. Results showed power (heat) input is the only statiscally significant factor on joint distortion. Locators type as well as welding sequence and simultaneous welding also had a measurable affect on part deviation during welding.