PICATINNY ARSENAL, N.J. -- A Soldier at a forward operating base needs the proper form to recommend an award for a fellow Soldier. He goes online, opens a form, fills in the blanks and hits "PRINT."


Another Soldier at a FOB needs a part for a weapon trigger assembly. Spare parts are not in storage. He goes online, opens the computer-aided design, or CAD, file for the trigger assembly and hits "PRINT."


Not to quibble, but James Zunino, a materials engineer for the U.S. Army Armament Research, Development and Engineering Center, would say that printing gun parts is no problem; it's just not possible to print qualified gun parts to military standards...yet.

"We've made a lot of parts and prototypes," Zunino said during a discussion about printed metal parts. But none of the parts have undergone a rigorous process to determine whether they were suitable to replace actual weapons parts.

"In theory, if you have a certified operator, certified materials and a certified printer, you can make qualified parts," Zunino said.

In today's Army, certified materials and printers to make qualified parts don't exist. However, uses for additive manufacturing and 3-D printing continue to develop. Zunino explained that metal parts are made using additive manufacturing in the medical and aviation industries.

Those materials are too obscure and expensive for military application now, but Zunino and his colleagues at Picatinny Arsenal, N.J., are laying out steps that would make it possible for a Soldier to print qualified metal parts to get parts faster while saving the Army money.

Zunino's colleague, Elias Jelis, is working on a doctoral project to qualify and set the parameters for a specific steel alloy additive manufacturing process using what's known in the industry as 4340 steel.

"Once you establish the process of qualifying one material you can use it to qualify another," Zunino said.

ARDEC engineers may also qualify 4140 steel, another alloy used in gun barrels, warheads and munitions parts, and others. They would then make parts from the metals and compare them against existing parts.

In such a comparison, data would be built on the structural differences between printed and machined parts, which would contribute to the effort to eventually qualify parts made from a 3-D printer.

Additive manufacturing is defined as a process of making devices or objects with an additive process, where successive layers of material are added or laid down in different shapes, rather than conventional subtractive processes that include removal of material such as machining, cutting, drilling, etching and carving.

Additive manufacturing of metals is often accomplished with help from laser-induced heat, called sintering, which bonds metal particles together to form the object being printed. Because of the way the material is applied in successive layers, printed materials have strengths in different orientations than from currently manufactured parts, Zunino said.

Knowing these characteristics, engineers might orient the way the object is printed so that the qualities of the printed part are consistent with the strength characteristics of a functional, durable part.