GM China’s Advanced Tech Centre begins trials of magnesium alloy VSC machine

The GM China Advanced Technical Center (ATC) in Shanghai has begun operation of its Vertical Squeeze Casting (VSC) machine – the first in the world designed for developing next-generation magnesium castings. This achievement marks a breakthrough in lightweight materials research by General Motors.

The new technology will make it easier to manufacture vehicle parts from magnesium alloy, which is lighter than aluminium and helps improve a vehicle’s fuel economy. Magnesium alloy is the lightest metal currently available for the mass production of automotive materials. A part made from magnesium alloy is 30 percent lighter than a part made from aluminium alloy. It is estimated that a vehicle's fuel economy will improve 7 percent for every 150-kilogram reduction in weight.

The VSC machine was jointly designed by GM’s lightweight materials research teams in Detroit and Shanghai. It was built in collaboration with an equipment manufacturer in China.

The VSC system is designed to improve casting integrity through the application of high squeeze pressure during the casting process. More importantly, its fully enclosed magnesium melting and transferring system can significantly improve the performance and quality of the castings, by maintaining the molten metal surface essentially isolated from oxygen which would otherwise produce oxide inclusions.

“The expected benefits of squeeze castings also mean we can use castings to replace some forged components at lower cost,” said Jeff Wang, Lab Group Manager of the materials research team at GM China Science Lab.

"Our efforts to promote magnesium alloy applications will not only meet customers' needs for better fuel economy and better performance at an affordable cost, but also take advantage of the ready availability of magnesium in China" said Wang.

China now accounts for more than 80 percent of global magnesium output.

The VSC machine in located in the micro-foundry and formability lab, which is part of the Advanced Materials Lab in the GM China Advanced Technical Center (ATC) that was opened in 2011. The ATC also has mechanical testing facilities, microstructure analysis, metallography and electrochemistry labs, and is focused on developing cost effective lightweighting technologies.

In May 2013, GM and its Pan Asia Technical Automotive Center (PATAC) joint venture in Shanghai received the 2013 International Magnesium Association (IMA) Awards of Excellence for the development and mass production of a magnesium-intensive decklid.

Photograph: Magnesium alloy vertical squeeze casting machine.