Rapid prototyping technology, building parts by creating a series of successive layers, began in the 1980s in Japan and immediately became a subject of interest in the U.S. The first patent, which coined the term stereo lithography (SLA), was granted in 1986 to Chuck Hull in the U.S. His 3D Systems company created the first prototype equipment in 1987 and launched the first commercial equipment in 1988.
Metal AM Beginnings: By the early 1990s, a half-dozen technologies based on layering principles were in the early stages of commercialization. Many subsequent approaches evolved from using liquids as the base material to using powders. Until the advent of powders, it was technically impossible to consider metal prototypes. The race to achieve metal prototypes now began. Twenty-five years later, the industry has achieved metal additive prototypes and is on the cusp of widespread Metal Additive Manufacturing (Metal AM).