Development and prospect of metal additive manufacturing technology

Additive manufacturing (printing technology) is a revolutionary manufacturing technology that integrates advanced manufacturing, digital manufacturing, intelligent manufacturing, and green manufacturing. It not only changes the way products are manufactured, but also changes the future production and lifestyle modes, thereby changing human life. Currently, 3D printing is mainly used for prototype manufacturing, mold verification, and direct manufacturing. Direct manufacturing refers to the direct use of 3D printing technology to produce final products, which is the focus of future 3D printing. In direct manufacturing, metal additive manufacturing is the most rapidly developing additive manufacturing technology and industry development at present, and has been widely used in related fields such as aerospace, biomedical, industrial molds, and power energy.

According to authoritative statistics and predictions, the global additive manufacturing market is showing a rapid upward trend (see Figure 1)[1], reaching $9.3 billion in 2018, and is expected to reach about $33 billion by 2025, of which 51% is in the automotive, aerospace, and medical fields. In the entire additive industry, the market size of the metal additive field has always been over 50%, and the industry output scale is growing continuously, accounting for an increasing proportion of the entire additive industry output every year.

The "Standard Terminology for Additive Manufacturing Technologies" (ASTM F2792-121a) standard, developed by the Additive Manufacturing Technologies Committee of ASTM F42, classifies additive manufacturing technologies into seven categories: Binder Jetting, Powder Bed Fusion, Directed Energy Deposition, Sheet Lamination, Material Jetting, Vat Photopolymerization, and Material Extrusion . All seven of these technologies involve the use of metal materials, with Binder Jetting, Powder Bed Fusion, and Directed Energy Deposition using metal powders. These three categories are the mainstream technologies for metal additive manufacturing and cover most application areas.

The application of material jetting technology in metal additive manufacturing is mainly to print metal circuits using nanoscale metal Ag, such as the technology adopted by Xjet Company; the material extrusion technology is to mix metal powders into the plastic matrix and realize the hot-melt printing of graphic patterns through this technology, such as the equipment of Markforged and DesktopMetal companies; the light polymerization technology is used in metal printing, mainly by adding metal or ceramic powders to the photo-sensitive resin, such as the additive equipment of Lithoz Company; the lamination technology is to realize the solid-state connection of metal foil by means of ultrasonic consolidation, such as the technology of Fabrisionic Company.

The classification of metal printing from the material dimension can be divided into metal powder printing, metal wire (bar) material printing, and metal foil material printing, i.e., particulate powder materials, one-dimensional metal materials, and thin film metal materials. According to the heat source for forming, there are laser, electron beam, arc, plasma, and ultrasonic heat sources.