For decades, the way you manufactured parts—whether for prototyping, tooling, or production—was simple: machining metal. You started with a chunk or bar of metal and carved away bits of it to create the part. This subtractive process (now sometimes known as “subtractive manufacturing”) is a tried and true method, but it’s necessarily limiting, particularly when it comes to internals. Since the outer shell of a shape is often the strongest part of its structure, any breach of that—say, to add definition or carve away unnecessary internal bulk—compromises structural integrity.
But then there was a revolution in manufacturing, courtesy of additive manufacturing (AM). The term encompasses a variety of processes, including material extrusion, material jetting, and photopolymerization, but the most widely known and accessible of them is 3D printing. In the early days of 3D printers, parts could be made only of nylon or ABS “thread,” but as the technology has developed, manufacturers gain increasing flexibility and freedom through the ever-growing list of materials that can be used for printing—including metal.
Early uses of additive manufacturing focused on rapid prototyping for pre-production visualization models—that’s what plastic parts were mostly good for. But as materials such as carbon fiber, fiberglass, Kevlar, and metal join the toolset, and as quality is equal or superior to traditional manufacturing processes, AM can be utilized for a wide variety of needs. AM can make everything from quick, nylon parts for fit-checks to end-use metal or Kevlar parts for aircraft, automobiles, dental work, medical implants, and more.
Choosing AM yields a variety of benefits, from the strength and integrity of the parts and related assemblies to efficiency and cost savings in the manufacturing process. To start with, AM parts require less material to create and generate less waste, since you’re building parts up, not cutting them away. That means you can use less of expensive materials—along with new, high-performance materials—and make optimal use of material properties. AM parts also result in increasingly sophisticated designs, because designers can make complex, internal structures—the kind of shapes that simply can’t be machined—that preserve strength and structural integrity while significantly saving money and weight.
In addition, creating parts via AM also helps the overall manufacturing process. AM is faster: parts that once had to be sent out for weeks or months to be machined can now be created in a day—and AM devices can work around the clock. If necessary, small groups of parts in a production run, or individual ones, can be modified with little turnaround time and zero tooling changes required. In some cases, such as short-run production, it might even be more cost-effective to produce all parts via AM, rather than manufacturing molds, die, and tools with which to make the parts.
When additive manufacturing processes are integrated with engineering and simulation software, engineers and designers can simulate and test designs before they get to commercial production and significantly reduce the cost of pre-production development.
Additive manufacturing won’t ever replace what forging, casting, and machining excel at, but the new processes and materials can help reduce costs and shorten turnaround time for parts production. At the same time, AM also helps push the boundaries of what it’s possible to manufacture—such as replacement parts for the human body—as well as how production fundamentally works.