Additive Manufacturing

The term “additive manufacturing” (AM) is being used more by manufacturers than “3D printing” when the subject is creating final parts instead of prototypes. Both terms refer to the process by which digital 3D design data is used to drive an additive fabrication process. Materials are built up in layers and hardened by various processes. Many brand of AM equipment use laser sintering, but other processes are also in use. AM equipment is very task- and material-specific; the exact brand and model you need depends on how the equipment will be used.

Best uses and benefits

Additive manufacturing can produce quality equal to — or superior to — traditional manufacturing processes. Whether a manufacturer uses traditional methods or AM depends on several factors:

Quantity: If tooling is involved, and the production run is very small,  creating parts using AM can be much cheaper than the cost of tooling and a traditional factory production run. Eliminating the need to create molds, die, and tools for a traditional run saves materials and energy, leading to a more sustainable manufacturing process.

Materials: New design methods in CAD are making it easier to create models that can only be manufactured by AM, using material strength and novel internal structure to essentially hollow out a part. The ability to create a light part with no waste is making it feasible to use more expensive materials like titanium or custom composites. Less weight means less consumption of energy, contributing to sustainability as a design criteria.

Variation: AM allows manufacture of a variety of slightly modified versions of a part, with immediate turnaround from one production run to the next.

AM is not a replacement for all traditional factory production methods. The best use of AM is in new approaches to manufacturing. AM allows highly complex structures to be lighter, stronger, and more stable than traditional parts. AM allows a true design-driven manufacturing process, eliminating late design changes for manufacturability.

The AM process

For AM systems using laser sintering, the process begins with application of a thin layer of material to the building platform. A laser beam then fuses the powder at precise points to define the first few microns of thickness. The build platform then lowers a precise distance, and the process repeated until the part is completed. Other processes such as stereolithography or electron beam fusion work in a similar fashion. Depending on the AM method, the material, and the exact brand and model of printer, there is sometimes post-printing finishing work to complete the part.

Going small is big

Miniaturization is becoming more import in manufacturing; the need for precision increases as parts become smaller. Medical technology, automotive, A&D, and the electronics and electrical industries are all finding new uses for precision parts in ultra-small dimensions. With precision measurable in microns, AM is a natural for the creating of the very smallest parts. AM can either build the parts or the demanding molds needed for larger manufacturing runs. Micro molded parts, micro eroding molds, and micro fluid mixers are all possible applications for additive manufacturing processes.

The brave new world of tool-less production

AM opens the door to creating tool-less production methods. The processes and advantages described above provide maximum freedom of design and the opportunity to rethink the entire art-to-part cycle. Building parts with internal functionality not possible to manufacture with traditional processes is one possibility. A workflow that specifies design variation is another. Placing the “factory” at the client site is another possibility. Rapid prototyping service bureaus are already gearing up to become manufacturing-as-a-service providers.