RAPID + TCT 2025, held at Huntington Place in Detroit, Michigan from April 8-10, 2025, is North America’s largest additive manufacturing and industrial 3D printing event. This annual event brings together industry leaders, experts, and innovators to showcase the latest advancements in 3D printing technology, share real-world solutions, and foster collaboration within the manufacturing community.
At this year’s RAPID + TCT event, Dr. Katelyn Kiser, Senior Metallurgical Engineer in the Center for Advanced Manufacturing, and Dr. Richard Billo, Director of the Center for Advanced Manufacturing and Director of Missouri Protoplex, presented on the development of custom wire material, particularly for large area additive technologies.
Missouri Protoplex at Missouri University of Science and Technology (Missouri S&T) play a crucial role in advancing manufacturing technology and processes. By participating in RAPID + TCT 2025, Dr. Kiser & Dr. Billo highlighted contributions to the development of custom wire materials for large area additive technologies, demonstrating how these innovations could reduce reliance on supply chains, enable specialty alloy trials, and accelerate production and prototyping.
Kiser and Billo’s presentation discussed the obstacles and overall viability of small batch wire production for novel wire feedstock grades. Large area additive technologies like Wire Arc Direct Energy Deposition (Wire-Arc DED) can reduce reliance on supply chains and allow for specialty alloy trials, creating faster turnarounds as needed for both production and prototyping. However, there are concerns about current weld wire grades meeting the surface finish and other specifications required for large area additive. Additionally, the supply chain isn’t vertically integrated, which makes it challenging to get small batches of any materials and even harder to get new or experimental compositions.
The laboratory scale setup at Missouri University of Science and Technology is capable of taking a variety of raw material forms and creating wire. The rod continuous caster allows for the feeding of up to 10 kg of alloy material and produces 6 mm diameter rod. This rod can be taken and inputted into the hot rolling setup. Whether using a commercial rod, sectioned material, or a rod cast in-house, the hot rolling setup feeds the material through an induction coil before it passes through progressively smaller openings in the square roller dies. Rods are reduced in this roller until the square cross section has a 1.5 mm edge length. This square rod is inputted into the cold drawing cell where it is deformed as it passes through successively smaller diamond dies. Once rounded, a laser micrometer can be used to monitor the wire diameter and measure roundness.
Throughout all the steps of this process, there are defects that present in the wire. During rolling and drawing, excess surface hardening can lead to scabbing and barbing, which can be mitigated through variation of annealing procedures or lubrication methods during the cold drawing process. Bending and breaking occur during the hot rolling process in areas of repeated thermal stresses from uneven heating and cooling. Fins can also form on the corners of the rolled material when rolling direction isn’t varied. With proper mitigation techniques in place for these common defects, Kiser and Billo proved that common weld alloy SS316 could be successfully drawn, free of defects. Additionally, the material maintained a final average diameter within 0.01 mm of the 1.15 mm target and over 99% round. When deposited using Wire-Arc DED and compared to commercial 316 feedstock, it was confirmed that no significant differences were observed.
This knowledge was used to begin the drawing work of a novel wire material, C96400. Difficulties casting the material into a rod revealed the need for the integration of rod oscillation into the caster. The study continued, rolling rectangular ingot sections. The lower toughness led to increased defects and break formation, but the produced wire sections drew cleanly down to 1.6 mm with most of the surface defects self-removing during cold drawing. Moving forward, the cupronickel studies will continue, and the rolling and drawing of more custom steel alloys will be pursued.
This ongoing research by Kiser and Billo at Missouri University of Science and Technology’s Missouri Protoplex is crucial for advancing manufacturing capabilities in Missouri and across the United States. By continuing to innovate in wire material development, Missouri S&T aims to support domestic manufacturing by offering solutions to reduce reliance on supply chains and enable faster production and prototyping of specialty alloys.