Steel used to make bunker-busting bombs adapted by the US Army for 3D printing. A low-alloy-steel powder with high toughness could one day allow soldiers in the field to 3D-print ultrastrong replacement parts. The powder is estimated to be about 50 percent stronger than commercially available feedstocks. A report on www.arl.army.mil quoted Dr. Brandon McWilliams, a materials manufacturing scientist at the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory, Aberdeen Proving Ground, Md, as saying “I think it’s going to really revolutionize logistics. Instead of worrying about carrying a whole truckload—or convoy-loads—of spares, you can potentially make anything you need as long as you have raw materials and a printer.”
The Army based the powder on the AF96 alloy the U.S. Air Force developed for making bunker bombs. The Army uses the alloy in powder bed fusion printers.
“We’re able to print up parts with internal structures that they would not necessarily be able to create with that much dimensional accuracy when they try to machine a part,” said Dr. Andelle Kudzal, a materials engineer on McWilliams’ team.
McWilliams noted that quickly printed, reliable 3D metal parts are still a long way off. The team has printed and delivered a usable empeller fan for the M1 Abrams tank, but the part isn’t qualified yet.
McWilliams said, “We still need to be able to answer, ‘Does this perform as good as the OEM part? Does this perform better?’”
McWilliams noted that there is resistance in some quarters to 3D-printed parts. “Some people think you can’t get good properties out of printed metal parts. We’re demonstrating that you can.”