Shanghai university creates aluminium and ceramic composite to reduce weight in transport sector

A team at shanghai jiao tong university blended aluminium and ceramic together to create a new composite material that is stronger and more rigid than titanium alloy. The breakthrough happened after nearly 30 years of research.

The composite known as "alumics‚" is now in the testing stage in C919 jets and Geely automobiles, and is expected to help aviation, automobile and high-speed rail industries in lightweighting and fuel economy.

"Ceramics is fragile in many people's mind, but its rigidity is actually even better than steel," said Wang Haowei, a professor at Jiao Tong's School of Material Science and Engineering who leads the alumics team.

A method used commonly across the world to make aluminium ceramic composite is to make ceramic particles or fibers and then add them into the aluminium alloy. Since, the particles are large; the blended materials show difficulty in moulding, low strength, poor plasticity and unstable quality. This prevents their use in industrial application, according to Wang.

As explained by Wang, the new method grows ceramic into aluminium to create a nano-material.

They were doing further development on a  method initiated 25 years ago by Wu Renjie, founder of the university's State Key Laboratory of Metal Matrix Composites.

"In metallurgy, nonmetal things are usually treated as impurities and should be getting rid of," said Wang. "But we found in our researches that they can also play favourable roles if we control the sizes, shapes and distribution of these particles by controlling chemical reaction process."

This new method helps improve the rigidity and strength of the new material while keeping the processing and manufacturing performance of aluminium alloy intact. "The nano ceramic aluminium alloy material helps break the bottleneck of large-scale application in engineering," Wang said.

The new composites are lightweight, strong, rigid, heat-resistant and anti-corrosive with qualities even better than titanium alloy. As said by Wang, the team is now cooperating with the Commercial Aircraft Corporation of China and AECC Commercial Aircraft Engine Co to apply alumics on China's domestically manufactured planes.

"Alumics is very suitable in making narrow-body jets like C919, while carbon fiber composites are more suitable for wide-body planes," said Wu Guanghui, chief designer of China's self-developed jet C919.

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Jiao Tong signed a contract with the government of Huaibei City of Anhui Province, Shanghai Junyao (Group) Co and the Anhui Xiangbang Composite Co to establish an alumics innovation center to promote civil use of the material.

"Compared with titanium alloy and high-temperature alloy, the performance of aluminium alloy with 3D printing technology is much lower. The 3D printing components made of nano ceramic aluminium alloy can achieve the performance of forgings," Wang said.