Padded Self-Piercing Riveting (P-SPR) on magnesium high pressure die casting
2022-01-0287
03/29/2022
- Event
- Content
- As a mechanical joining technology well established on aluminum and steel, self-piercing riveting (SPR) is exploring its application on magnesium. The main issue with the development of magnesium SPR technology is the button cracking which is ascribed to magnesium’s limited slip systems in room temperature. To address the issue at room temperature, an innovative padded self-piercing riveting (P-SPR) process was developed to mitigate the cracks by integrating a disposable pad into the rivet setting process. An experiment was designed to join a piece of 2.0mm thick 6061-T6 aluminum to a piece of 3.2mm thick powder coated AM60B magnesium high pressure die casting (HPDC) under 3 different configurations including the conventional SPR process as a baseline, the conventional SPR process with an optimized die and the P-SPR process. Through the comparison on button surface, cross-section and joint strength, the P-SPR solution with a joint strength of 6.5kN protected both metal and powder coating from cracking. The numerical result reveals that the effect of pad on crack mitigation can be ascribed to the reduced stress concentration during the rivet setting process. With the flexibility of pad material selection and the compatibility with existing SPR process line, P-SPR process shows great potential to be an enabler for more SPR applications on the materials with limited ductility.
- Citation
- Liu, Y., Wang, G., and Weiler, J., "Padded Self-Piercing Riveting (P-SPR) on magnesium high pressure die casting," SAE Technical Paper 2022-01-0287, 2022, .