When I was a student at university, a major theme is the progressive development of materials having ever greater strength and heat resistance, primarily to meet performance objectives. Unfortunately, the characteristics of such materials present challenges to the principal shaping processes of forming and material removal in reaching the complex shapes required. This, in turn, led to a parallel trend toward net shape to reduce or eliminate the negative aspects of material removal.
In more recent times, however, a completely different approach to shape making has evolved in which basic materials in liquid or particulate form, as well as filament or sheet form, are assembled point by point or layer by layer into the objective shape. Using the pinpoint accuracy of a laser, miniscule droplets from a printhead, or extrusion of material through a narrow nozzle, a variety of clever mechanisms have been devised to carry out these high-resolution building processes, now collectively known as ADDITIVE MANUFACTURING (AM), and frequently referred to as 3D printing.
If you are new to this field, reading two below references are recommended:
- ISO/ASTM 52900 on terminology for AM, issued in 2015 and replacing the older ASTM F2792 and ISO/CD 17296-1 terminology standards.
- ASM Handbook, Vol. 24; Additive Manufacturing Processes, 2020