In September 2026, car manufacturer Li Auto and supplier Duoli Technology presented a one-piece magnesium rear underbody in Changzhou. The component was produced on a 9,200-tonne die-casting machine from Bühler. According to the companies, it took around three months from the start of the project to the first prototype.
Manufacturing such components is demanding: molten magnesium must be protected against oxidation and flow over long distances before solidifying. Temperature control, die design and venting all play a role in preventing porosity and other defects. Duoli used a specialised melting and casting system. However, the successful prototype provides no indication of scrap rates or cycle times in series production.
Chongqing-based car manufacturer Changan is also working on large magnesium structures, according to industry expert Luca Greco. Its subsidiary ChenZhi Lightweight has developed a magnesium inner tailgate panel. Measuring 1,487 × 1,263 millimetres, the component reportedly has a wall thickness of just 2.5 millimetres and replaces nine previously separate sheet-metal parts. According to the company, the resulting tailgate assembly is 45 per cent lighter than a comparable steel structure. The casting was reportedly produced on a 5,000-tonne machine equipped with a module for processing magnesium in a semi-solid state. In September, ChenZhi discussed potential applications and series production requirements with Seres, another car manufacturer based in Chongqing. No order was announced.
Thixomoulding Reaches New Dimensions
Further developments documented by Luca Greco in his Gigacasting Newsletter show that these are not isolated projects. Greco, who has previously been interviewed by EUROGUSS 365, monitors developments in gigacasting and magnesium processing worldwide.
In thixomoulding, magnesium chips are plasticised in a heated screw barrel and injected in a semi-solid state. This can reduce certain casting defects but requires precise control of temperature, solid fraction and flow behaviour. The suitability of a particular process also depends on the component and production volume.
One example is a die-casting cell from Haitian with a clamping force of 7,000 tonnes and two injection units. According to the manufacturer, its theoretical shot weight exceeds 38 kilograms. At the end of September 2026, Waffer Technology reported successful tests of such a machine in Maanshan. Haitian identifies instrument panel cross-car beams, inner door panels and tailgate structures among its potential applications. However, this does not yet demonstrate that these components can be manufactured in high-volume series production.
Tianhao New Materials initially intends to purchase nine thixomoulding machines, with clamping forces ranging from 700 to 3,600 tonnes, for a new plant in Huizhou. The machines are scheduled to be installed and commissioned in the first half of 2027. In Michigan, Leggera Technologies is expanding its production facilities by approximately 4,200 square metres to accommodate additional equipment, according to industry reports.
The Machine Is Not the Only Deciding Factor
Another project illustrates the importance of alloy development: in August 2026, Wuling Industry and Chongqing University developed a magnesium housing for electric drive systems using thixomoulding. The project partners addressed several challenges, including the material's creep behaviour at high temperatures, corrosion resistance, porosity and the housing's leak-tightness. In addition to the alloy, component design, die design and process parameters were coordinated. Greater clamping force alone is therefore not enough: the material, component and manufacturing process must work together.
With a density of around 1.7 to 1.8 grams per cubic centimetre, magnesium is approximately one-third lighter than aluminium. However, weight savings in finished components are often smaller because different wall thicknesses may be required. Corrosion protection and joining techniques must also be considered.
Raw material prices also influence economic viability. In October, Waffer pointed out that certain aluminium alloys in China were around 30 per cent more expensive per tonne than a magnesium alloy. However, what ultimately matters is the total component cost, including processing, reworking and scrap.
From Prototype to Series Production
According to the Gigacasting Newsletter, the Chinese magnesium producer Baowu Magnesium, which is part of the state-owned Baowu Group, reported in September that Chinese companies were increasingly testing large magnesium rear underbodies and structural battery components with a view to series production. However, no reliable production volume figures were provided.
These developments also create new lightweight design opportunities for European die-casting foundries, but they involve investment risks. Machinery manufacturers such as Bühler are already involved in the development process. Whether magnesium becomes more widely used in large automotive body structures will ultimately depend not on maximum clamping force, but on the ability to achieve consistent component quality at an economically viable cost.
