Cost and Weight Optimization of Magnesium Power Train Components by Using Aluminum Thread Forming Fastener Technology

The current state of technology for fastening magnesium power train components is the use of metric steel or aluminum bolts. Due to physical and chemical properties of the used materials, difficulties like high clamping load loss at elevated temperatures and strong corrosive attack which requires costly corrosion protection systems must be taken into account. The objective of this project was to develop and to evaluate a high-strength thread forming aluminum bolt for magnesium components regarding mechanical properties, relaxation and corrosion behavior. Benefits of this bolt connection system are weight reduction in comparison to steel bolts, lower loss of clamping load, less contact corrosion and cost reduction by using thread forming technology (elimination of drilling and thread cutting operations). This paper discusses the applicability of high-strength thread forming bolts in magnesium nut material focused on mechanical properties of the aluminum bolt, relaxation and corrosion behavior of the bolt connection.