Over the past several years, multiple organizations have conducted a life cycle analysis on the use of magnesium as a replacement material in automotive and aerospace applications. In two separate studies, magnesium was used as: a replacement material in chassis, interior and body structure of a base vehicle; a replacement material in steering wheels and; as a material for parts of an aircraft door. Within these studies, it was essential to identify a quantitative measure of energy use and greenhouse gas (GHG) emissions throughout the magnesium life cycle. These measurements could then be compared with products with lower amounts of magnesium to assess if the replacement was beneficial.
The majority of the world's magnesium is produced in China using the Pidgeon process which has improved in efficiency over the past few years. The magnesium life cycle contains four major parts — materials production, manufacture of parts, product use, and end of life.
The magnesium used within the vehicle chassis, interior and body structure resulted in an 83kg weight savings compared to the base car. This weight savings only lowered the GHG emissions 0.80% and the energy usage by 1.3% over the course of the life cycle. The same analysis was also conducted on a vehicle with 83 kg of weight reduction due to magnesium replacement as well as an additional 23kg of secondary weight reduction and the use of a smaller motor. In this second scenario, through the life cycle, GHG emissions and energy usage is reduced by 15%. As gas prices increase, the operation cost savings in the second scenario also increases compared to the first scenario. There is a 90% reduction of GHG emissions and energy usage in production of recycled magnesium as opposed to primary material. Automotive applications of magnesium are in the operation stage for approximately 80% of their life cycle. Due to this fact, the use of recycled magnesium does not make as great of an impact on reducing GHG emissions and energy usage over the length of the lifecycle.
Both studies showed that magnesium as a lightweight material in automotive and aerospace applications are viable and material cost, fuel cost and production method all affect the reduction in GHG emissions and energy usage. It has also been concluded that additional research must be done to further improve the positive effects that result from magnesium use in such applications as the material boasts a lot of potential for wider use.