TOKYO—Researchers in Japan have developed a new additive manufacturing technology for making high-precision parts with lightweight magnesium alloys.
The technology was invented by researchers from Mitsubishi Electric Corp., the Kumamoto University Magnesium Research Center, Toho Kinzoku Co., and the Japan Aerospace Exploration Agency (JAXA).
The technology uses a laser to melt magnesium wire under cover of a shielding gas. The process could enable the creation of precise, complex components that are lighter and stronger than those made of steel or aluminum. The technology could be used to make parts for cars, airplanes, rockets and other applications. The technology is also more energy efficient and environmentally friendly than other processes for forming magnesium.
Magnesium alloys are attracting attention the aerospace and automotive industries for their high strength and light weight. However, magnesium alloys are typically processed by die casting, making it difficult to create structures with hollow interiors. The laser-based additive manufacturing process overcomes that limitation.
The researchers also say their technique is better than the powder bed fusion method for additive manufacturing with metal, which uses heat to selectively melt metal powder. That technique carries a risk of dust explosions, and metal parts made with the powder bed fusion method can degrade due to oxidation.
The wire used in the new method is made from Kumadai, a nonflammable heat-resistant magnesium alloy. Precise temperature control prevents combustion of the metal.
JAXA estimates that rocket parts made with the new technology could be 20 percent lighter than those made from traditional aluminum alloy structures. Parts produced with the technique achieved a tensile strength of 250 megapascals (MPa) at room temperature and about 220 MPa at temperatures of 200 C, which is equal to or better than parts made with conventional methods. The samples have also been shown to be heat resistant and nonflammable.
