Effects from pinless friction stir spot welding parameters to lap joint welding strength of aluminum A5052-H32 and A6061-T6

Nowadays, automobile manufacturers tend to increase using of light material such as aluminum. But conventional assembly technique like resistant spot welding still has problem about oxide film on surface and weld joint. So, pinless friction stir spot welding was developed to solve the problem. This research studied effects of welding variables to lap shear force at welding joint on dissimilar aluminum A5052-H32 and A6061-T6 with 1 mm thickness. The variables were welding time, tool penetration depth, and tool diameter. Result was found that, the best variable set, for using of 7 mm tool, are A5052-H32 at top side, welding time 17 s, and tool penetration depth 0.59 mm. For using of 10 mm tool, the variables are A6061-T6 at top side, welding time 20 s, and tool penetration depth 0.54 mm. Both cases provided highest lap shear force. The tool penetration depth which is acceptable to all welding conditions was between 0.4 – 0.6 mm.