Researchers 3-D Print Biomedical Parts With Supersonic Speed (phys.org) 14
schwit1 shares a report from Phys.Org: Forget glue, screws, heat or other traditional bonding methods. A Cornell University-led collaboration has developed a 3-D printing technique that creates cellular metallic materials by smashing together powder particles at supersonic speed. This form of technology, known as "cold spray," results in mechanically robust, porous structures that are 40% stronger than similar materials made with conventional manufacturing processes. The structures' small size and porosity make them particularly well-suited for building biomedical components, like replacement joints.
The team's paper, "Solid-State Additive Manufacturing of Porous Ti-6Al-4V by Supersonic Impact," published Nov. 9 in Applied Materials Today. "If we make implants with these kind of porous structures, and we insert them in the body, the bone can grow inside these pores and make a biological fixation," Moridi said. "This helps reduce the likelihood of the implant loosening. And this is a big deal. There are lots of revision surgeries that patients have to go through to remove the implant just because it's loose and it causes a lot of pain." Moridi added: "We only focused on titanium alloys and biomedical applications, but the applicability of this process could be beyond that. Essentially, any metallic material that can endure plastic deformation could benefit from this process. And it opens up a lot of opportunities for larger-scale industrial applications, like construction, transportation and energy."
The team's paper, "Solid-State Additive Manufacturing of Porous Ti-6Al-4V by Supersonic Impact," published Nov. 9 in Applied Materials Today. "If we make implants with these kind of porous structures, and we insert them in the body, the bone can grow inside these pores and make a biological fixation," Moridi said. "This helps reduce the likelihood of the implant loosening. And this is a big deal. There are lots of revision surgeries that patients have to go through to remove the implant just because it's loose and it causes a lot of pain." Moridi added: "We only focused on titanium alloys and biomedical applications, but the applicability of this process could be beyond that. Essentially, any metallic material that can endure plastic deformation could benefit from this process. And it opens up a lot of opportunities for larger-scale industrial applications, like construction, transportation and energy."
More info: (Score:5, Informative)
Abstract [sciencedirect.com]
Cold spraying [wikipedia.org]
From what I understand, the material is accelerated so that the impact raises the energy enough so that it will bond. In this case, the "cold spraying" happens between 800 and 900 Celsius. The melting point of the alloy is 1626 Celsius so it's "cold".
Re: (Score:2)
That's gonna take a bit more than an IKEA ABS heating enclosure wrapped around my Prusa.
Ultrasonic printing (Score:3)
Maybe a printer could use highly focussed ultrasound, varying the levels of energy released by cavitation to either dissolve material (subtractive 3D printing ), or, at another spot, bond new material (say, powder or filament) precisely where needed (additive printing; ultrasonic welding). In fact, there could be multiple filaments or powder feeds coupled to the print head -- e.g, metal filament, plastic powder, etc.
Re: (Score:2)
I think not: the spread of energy from the ultrasound would be too large and deposit too much heat on the _rest_ of hte printed object. With wavelenghs of roughly a centimeter, they can't be focused tightly enough for focusing on small joint or 3D printing gargets.
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Oh, my, Please forgive my typing, I'm at a new home desk setup.
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Ultrasound isn't going to work, but microwaves might. You can melt down aluminum in an ordinary microwave oven with some minor modifications. You might be able to heat the work with a purpose-built microwave radiator. (Or even smaller waves, for more accuracy.)
Could be used at home ? (Score:1)
Re:Could be used at home ? (Score:5, Interesting)
It looks like it's essentially inkjet printing of titanium. You still have to get the metal quite hot in order for it to bond when the particles strike, and they are delivered in a stream of "gas" which wasn't specified in either the article or the abstract, but it is usually helium or argon used for welding titanium. If the process was refined sufficiently then it might be possible to scale it down and make small parts at home, but it's probably not going to be affordable any time soon. The total amount of heat energy is small, but the temperatures are high, so making it work on your workbench will likely be challenging.
Re:Could be used at home ? (Score:4, Interesting)
The temperatures are far lower than in a home ceramic kiln (as a rule, rock has a higher melting point than metal), so I don't think that will be a huge problem. It will drive the price up a bit, but a small kiln can be had for a few hundred dollars.
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You don't typically 3D print ceramics inside a running kiln.
Nevertheless, these temperatures seem quite manageable for even the intricate mechanics, though far from hobby grade.
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Sure, but we know how to deal with the temperatures at home. And the equipment presumably can deal with the temperatures already, or they couldn't be printing anything. It might add active cooling as a consideration, but "requires hot tub installation" is probably not going to dramatically reduce the number of people who would want one.
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the temperatures are high, so making it work on your workbench will likely be challenging.
High temperatures aren't that big a deal for home hobbyists. Mig, tig or oxy-gas welding are simple. As are ceramic kilns.
The marketing writes itself (Score:2)
"You want a new part? BOOM!"