3D printing technology classification

3D printing technology, a revolutionary force in the manufacturing industry, exhibits significant technical differentiation due to differences in material properties. Based on the physical properties of the molding materials, current mainstream technologies can be clearly divided into two main systems: non-metallic and metallic. These systems contrast sharply in terms of technical principles, equipment structure, and application scenarios.

Non-metallic 3D printing, based on polymer materials, ceramic powders, photosensitive resins, and other materials, has become a mainstream choice in the consumer market and light industrial sectors due to its low equipment cost and material compatibility. For example, fused deposition modeling (FDM) melts thermoplastic filaments such as PLA and ABS through a heating device and then extrudes them layer by layer, creating a buildup similar to squeezing toothpaste. With a low entry point (desktop models cost in the low thousands of yuan range), material utilization rates exceeding 90%, FDM is widely used in educational teaching aid production and product prototyping.

Stereolithography (SLA) and digital light processing (DLP) use ultraviolet light to trigger the curing of liquid photosensitive resins, achieving precisions of less than 0.05mm and smooth surfaces. They are commonly used in the medical field for the prototype production of dental models and precision instrument components. Selective laser sintering (SLS) and multi-jet fusion (MJF) use a laser or thermal nozzle to activate the bonding between powder particles. Without support structures, they can print hollow or nested structures and are commonly used in the automotive industry for prototype production of engine intake manifolds.

Metal 3D printing addresses the needs of high-end manufacturing in aerospace, medical devices, and other fields, overcoming the challenges of forming complex structures and high-performance materials that are difficult to achieve with traditional machining. Selective laser melting (SLM) uses a high-power fiber laser to completely melt metal powders such as titanium alloys and stainless steel with precisions of 0.02mm, enabling the creation of millimeter-thin structures. The titanium alloy wing rib brackets of the Airbus A350 are manufactured using this technology, achieving a 15% weight reduction while meeting high strength requirements. Electron beam melting (EBM) uses an electron beam to heat metal powder in a vacuum environment. It's suitable for reactive metals with high melting points. The material is continuously preheated (500-700°C) during the printing process, significantly reducing stress and deformation. It's commonly used in critical load-bearing components such as aerospace engine impellers. Direct energy deposition (DED) uses a laser/arc to melt metal wire or powder and simultaneously deposit it onto a substrate, enabling the rapid manufacture and repair of large components (meter-scale). General Electric uses this technology to repair aircraft engine blades, reducing the cost by 70% compared to replacing new parts. For example, UnionTech's Muees series of metal 3D printers (such as the Muees 430) utilize a multi-laser system, boasting a build area of ​​up to 430×340×400mm and a scanning speed of up to 6m/s. This provides efficient production solutions for metal molds, aerospace components, and other applications.

Behind this technological differentiation, non-metallic technologies are driven by "universalization," expanding into consumer applications through material innovations (such as biodegradable PLA and conductive nylon). Metal technologies, on the other hand, are pursuing "higher performance" and penetrating high-end manufacturing applications in aerospace, energy equipment, and other sectors. The two technologies differ significantly at the underlying level: non-metals rely on phase transitions (melting-solidification/photosensitive reaction), while metals rely on metallurgical bonding (melting-sintering), resulting in significant disparities in equipment complexity and process difficulty. With advances in materials science (such as nano-enhanced resins and ultrafine metal powders) and equipment intelligence (AI-optimized printing paths), the two technological systems will forge synergies in more areas, accelerating the evolution of 3D printing from "prototyping" to "mass production."

From plastic toys to aerospace components, different technological approaches are like precision gears, collectively driving the gears of the manufacturing revolution. While the consumer market is captivated by the creative monetization of color resin printing, the industrial sector is using titanium alloy powder to shape the future of aviation engines. This technological differentiation, driven by material properties, is a sign of the maturity of the 3D printing industry ecosystem.