Magnesium alloy is a very good candidate for replacing steel, ABS plastic, and aluminum currently used in automobile parts production. It is only two-thirds the weight of aluminum and one-fourth the weight of steel. It has excellent dampening capacity and has high dimensional stability. These properties allow for reduced weight of vehicles, thus saving gas and reduce emissions without compromising safety. When magnesium alloy is manufactured as a sheet it is easily used in auto parts stamping. The only downside is that production of such magnesium alloy sheets is expensive using the current method of rolling. However with this innovative patented extrusion-flattening technique, the cost can be reduced to as low as one-third to one-fourth the cost of rolling depending on width and thickness. At this cost, it is very comparable to the cost of aluminum stamped parts. This will allow magnesium sheets to be able to very effectively be integrated into stamped auto parts design.
The hexagonal close packed structure of magnesium makes the rolling method for production inefficient. When rolling magnesium alloy sheets using the traditional method the sheets must go through multiple stages of rolling and annealing. This process is not only time consuming but causes residual-stress in the sheets and can cause the sheets to crack when they are worked upon in downstream products, such as when stamped for automobile parts. The extrusion-flattening process produces extruded tubes of magnesium alloy which is then cut and flattened to produce sheets. This output method is much more streamlined and the quality of sheet output improved. Because the process is leaned there are cost savings monetarily as well as environmentally through more efficient energy usage. The end result produces a higher quality sheet because there is dramatically reduced residual-stress.
Using currently available commercial equipment the alloy sheets can be produced up to 600 millimeters (23.62 inches) wide with a thickness range of 1.5mm (1/20th inch) to 6mm (1/5th inch). Through careful selection of alloy composition these alloy sheets are also laser weld-able at a rate of 40 meters per minute (a little over 100 feet a minute). The welding seams are also very strong, generally only a 5% difference in strength at the seams compared to the base material. In order to make sheets more resistant to corrosion, a commercialized zinc coating process can also be applied to the sheets.
The magnesium alloy is 100% recyclable. At the end of the downstream product life-cycle the parts can be stripped of their coatings and reworked to be used for new parts.
Currently the magnesium alloy sheets produced through this process are being promoted in automobile seat frames and instrumentation panels stamped parts.
ABOUT THE ENTRANT
Name: Wuliang Zhang
Type of entry: team
Software used for this entry:
Patent status: patented