A Case Study of a Die-Cast Magnesium Structure Supporting Transmission Shifter Mechanisms and Interfaced with other Structural Systems

During the last several years the use of magnesium die-castings for automotive applications has been on the rise. Magnesium's use in die-cast form has been expanding at an average growth rate of more than 15% a year. Reasons for the increase are both practical and economic. Magnesium die-castings offer components having the lowest mass when compared to almost any other structural material. Magnesium die-alloys exhibit properties that bridge the gap between engineered plastics and metals. The mechanical performance ratios (strength-to-weight and stiffness-to-weight) of magnesium also compete favorably with metals and plastics. Economically, magnesium alloys prices have fallen during the last several years making them extremely competitive with other materials. This combined with strategies that reduce total systems costs of a vehicle (such as part integration, net-shape part design, and lower vehicle assembly time) are making stronger business cases that justify magnesium's long-term use. In order to underscore the advantages for magnesium's use, this paper summarizes the recent decision to use a magnesium die-casting for a transmission shifter structure. The component is unique because it is a single magnesium die-casting that is used to tie together three distinct structural systems within the vehicle (cross-car beam, transmission shifter mechanism and body floor).