Magnesium-aluminum price ratio at 0.72 window period, automakers are accelerating "magnesium replaces aluminum" lightweight layout [SMM survey]

Since 2026, breakthroughs in processes such as semi-solid die-casting, coupled with a pullback in the magnesium-to-aluminum price ratio, have accelerated the penetration of magnesium alloy automotive die-castings from small non-load-bearing parts to core structural components such as electric drive housings and rear floors. Application achievements from four large enterprises have been intensively realized.

The world's first semi-solid magnesium alloy instrument panel crossbeam (CCB) entered mass production, supporting Seres' AITO car models. Produced using semi-solid die-casting, it weighs less than half of a traditional steel counterpart, with a stable daily output of 1,000 units. Meanwhile, Changan jointly trial-produced an integrated magnesium alloy rear floor die-casting with a 67% yield rate, setting a new industry record, achieving a weight reduction of over 20% compared to aluminum parts.

 Guangdong Hongtu and SAIC-GM-Wuling successfully trial-produced a magnesium alloy electric drive housing die-casting, using the self-developed JDM1c heat-resistant die-casting magnesium alloy, formed on a 4000T ultra-large die-casting machine. The housing weighs 11.28 kg, achieving a 35.73% weight reduction compared to the aluminum alloy solution, and is expected to be installed in vehicles by year-end. Previously, the ultra-large magnesium alloy electric drive housing jointly developed with Changan also achieved a 23% weight reduction.

Sinyuan ZM secured 4.094 billion yuan in designated orders for magnesium alloy powertrain housings within one year, approximately ten times its 2024 revenue. The largest single order was for Xiaomi Auto's die-casting project, expected to commence mass production in Q3 2026, with a four-year scale of 2.021 billion yuan. The products use high-pressure die-casting and cover medium to large die-cast parts such as new energy vehicle powertrain housings and display system components. Clients include BMW, Audi, Zeekr, and XPeng.

Chenzhi Lightweight and Changan Auto established a joint project team in July, focusing on the mass production of large auto body die-castings, including magnesium alloy electric drive housings, rear floors, and rear door inner panels. They are building an integrated smart manufacturing base that encompasses R&D, trial production, manufacturing, and validation. Previously, they signed a joint development agreement with Avatr covering eight product areas, including CCB and tailgates, using semi-solid die-casting, to promote magnesium alloy penetration from non-load-bearing parts to core structural components.

Magnesium alloy automotive die-castings are upgrading from small parts such as steering wheels and seat brackets to medium and large core structural components including electric drive housings, CCBs, and rear floors, achieving weight reductions generally ranging from 20% to 35%. The maturity of semi-solid die-casting and integrated die-casting processes, combined with the pullback of the magnesium-to-aluminum price ratio to 0.72, has shifted magnesium alloy from an optional to a mandatory lightweight solution. Based on a usage of 50 kg per vehicle, the incremental demand for magnesium alloy in the automotive sector could reach a million-ton scale.