The collection of things we call additive manufacturing (AM) and 3-D printing may – and perhaps should – be changing, thanks to a mix of technological progress, the offerings of new companies in those business areas, and even a bit of industrial history.
According to Merriam-Webster, AM is defined simply as 3-D printing, and the term dates to 2007.
However, I like this definition from SPI Laser, one of the world’s leading Fiber Laser design and manufacturing companies: “…rather than producing an end result by taking material away, it adds to it instead.” Since they’re acknowledged industry experts, it’s fair to take a fresh look at the term and expand its meaning. I propose this change: while all 3-D printing is by definition AM, there is AM that is not – or not quite – 3-D printing.
In fact, if we take “additive manufacturing” at face value by using the SPI definition above, then it’s been around much longer than the term itself. Weld overlay is an excellent example – it’s defined as “us[ing] a welding process to melt a material onto the surface of another, different material” (from Corrosionpedia.com). It’s a common process for cladding, in which a more corrosion-resistant metal is added to a less corrosion-resistant one to get the best of both worlds. So when Berry Keeler and his fine team at Cust-O-Fab, Inc., in Sand Springs, Oklahoma, welded stainless steel cladding onto huge carbon steel condenser lids as part of a retrofit job I ran many years ago, I submit that they were engaged in AM.
Given, that’s a pretty limited example, and they weren’t building whole parts via additive technology. Much more recently, the enormous leaps in technology that have enabled the rapid growth of full-scale 3-D printing have also set the stage for other manufacturing methods that fit within the AM umbrella, but may not fit within the 3-D printing one.
I’ve written previously about Electroimpact (EI) in Mukilteo, Washington (see that article here). They do all kinds of remarkable things to provide automated assembly solutions for the airliner industry. One of the very coolest of these they call “automated fiber placement” (AFP), in which they use large-scale industrial robots and custom-designed effector heads (the tool at the end of the robot arm) to lay down carbon fiber and build complete aircraft parts layer by layer. This almost certainly wouldn’t fit the definition of 3-D printing, but I don’t see how it isn’t within the realm of AM.
A similar example is Fabrisonic, of Columbus, Ohio. Their technology, Ultrasonic Additive Manufacturing (UAM) is a hybrid additive and subtractive technology. Their raw material is thin strips of metal that they bond together using ultrasonic welding, in which applied force and ultrasonic vibration combine to create molecular bonds between the strips, which are added layer by layer to achieve the desired gross dimensions, then milled afterward to achieve the final part shape. Because their forming temperature never exceeds 200 degrees F, they’re able to maintain the fundamental material characteristics, and are also able to embed sensors and electronics. They’re also able to combine dissimilar metals. They’re therefore able to form parts that simply aren’t possible with any other technology. They’ve already appended the AM term for their technology, which most people would definitely not consider 3-D printing. Fabrisonic is a small private company that was a spin-off of a non-profit. They’re currently self-funded, though “that may have to change,” according to Mark Norfolk, the company’s President. They sell both their production machines and parts that they make as a service bureau.
A final example blurs the lines – it fits the general definition of 3-D printing, but isn’t part of the official pantheon of those technologies. SPEE3D of Australia has developed “supersonic 3-D deposition,” in which a custom-designed nozzle shoots metal powder at supersonic speeds to build parts layer by layer, similar to some 3-D printing technologies – but 100 to 1,000 times faster. Like EI above, they use a standard large industrial robot as part of their process; SPEE3D uses it to hold thepart and constantly adjust its position relative to the nozzle to achieve the proper build shape. The powder particles impact the build surface with such force they create molecular bonds, resulting in “an end part with 99% density, versus 95% for cast metal parts,” according to co-founder and CEO Byron Kennedy. They’re able to work with 6061 aluminum and copper, and they’re beginning to work with bronze and mixed metals as well. Uniquely, they’re able to compete with mass-production technologies for simple industrial parts, such as hose nozzles, because of their build speed and economics. Their finished parts are used straight from the build process in some cases, though they undergo post-process heat treatment and machining for other applications. SPEE3D has been selling both parts and machines for about 18 months now, according to Kennedy, in the UK, U.S., Australia and Singapore. The company was established in Australia, and is currently opening offices in the U.S.
There are surely more examples of companies and technologies that challenge our current definitions of 3-D printing and AM. The rapid development of use cases and applications that fit them will challenge these notions further and faster.
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