GUANGZHOU, Nov. 3 (Xinhua) -- In the laboratory of the Dongguan Institute of Materials Science and Technology (DIMST), under the Chinese Academy of Sciences, researchers have developed a remarkable metal: a material so thin and lightweight that it can be torn by hand, much like a sheet of paper.
Researchers have called it "hand-tearable steel."
The material is at the heart of the Quark electric drive system developed by Chinese automaker GAC Group. It has helped the system achieve a peak efficiency of 99 percent and underpins the automaker's claim that three new mass-produced GAC Aion models can travel an extra kilometer on every kilowatt-hour of electricity.
Scientifically known as an amorphous alloy, the material is commonly known as metallic glass. Its revolutionary properties stem from the way its atoms are arranged.
Zhou Jing, an associate researcher at the DIMST, explained that conventional silicon steel is a typical crystalline material, with atoms arranged in neat order, much like students lined up on a playground.
By contrast, amorphous alloy is manufactured using an extremely rapid cooling process. The alloy melt is heated to 1,300 degrees Celsius and then cooled in an instant, leaving the atoms no time to queue up and crystallize, effectively freezing them in a disordered state.
The atomic structure gives the material its distinct properties. The amorphous alloy strip is only 0.025 millimeters thick, roughly one-fifth the diameter of a human hair and one-tenth the thickness of an ordinary silicon steel sheet.
Amorphous alloy belongs to a high-performance category of soft magnetic materials used to manufacture motor cores. For soft magnetic materials, the thinner the material, the lower the eddy current loss -- energy dissipated as heat when magnetic fields induce electrical currents in the motor core.
"The biggest challenge for electric motors is energy loss," Zhou said. "With a conventional motor, if you feed in 100 units of electricity, part of it is wasted as heat. An amorphous motor loses only one unit, with the remaining 99 percent converted into real driving force."
However, translating these laboratory properties into a material capable of being used to mass produce cars has proven far from straight forward.
Installing amorphous material in a vehicle means it must withstand tens of millions of vibrations, thousands of high-low temperature cycles, and operate stably for more than a decade.
"Preparing a few grams of sample in the lab isn't difficult, but bridging the vast engineering gulf between a sample and industrial mass production is another matter entirely," said Qi Hongzhong, president of GAC Group's Powertrain Business Unit.
A conventional silicon-steel core requires only 384 stacked layers, whereas an amorphous core needs nearly 3,800 layers, almost 10 times as many. Each layer is thinner than a strip of paper, yet significantly tougher than conventional silicon steel.
Being nearly five times harder makes conventional stamping processes unsuitable, with even the slightest deviation affecting the quality of the finished core.
To overcome these obstacles, the research teams from the DIMST and the GAC Group jointly developed a complete set of non-standard production lines covering stamping, precision stacking, and supporting heat treatment, turning small lab samples into automotive-grade components that could be mass-produced.
AI has been integrated throughout the entire process of composition design, performance prediction, process optimization and production line deployment. By greatly decreasing the need for repeated trial-and-error cycles during R&D, the technology introduced by the DIMST team has enabled the material to progress more quickly from a lab to stable manufacturing and batch delivery.
The collaboration has moved beyond the research stage. The DIMST and GAC Group's Powertrain Business Unit signed a strategic cooperation agreement in August this year. Three mass-produced GAC Aion models equipped with amorphous alloy electric drives have been unveiled successively as of September this year, marking this technology's transition from joint R&D to scaled application.
Vehicle validation showed that core loss in the motor dropped by 50 percent, with a peak efficiency of 99 percent. Under real family road-trip conditions on the ring expressway of China's southern island province of Hainan, measured electricity consumption per 100 km was as low as 8.571 kWh.
Targeting the needs of emerging industries such as new energy vehicles, high-end equipment and green energy, the DIMST is conducting joint research with multiple enterprises in directions including AI power supplies, solid-state transformers and bulk amorphous structural materials. ■
