On Monday, May 19, 2025, Dr. Dave Gildemeister [CINDAS LLC] and I had the opportunity to receive a tour of Haynes International's Manufacturing Facility in Kokomo, Indiana. Haynes International manufactures superalloys for high-temperature and highly corrosive environments, producing for a range of industries including aerospace, chemical production, and power generation. As a senior in aerospace engineering at Purdue University, I have had very limited experience with metallurgy and the processes involved in the manufacturing of alloys my industry needs to continue pushing the performance envelope; therefore, this visit was quite fascinating. Our tour guide, Quentin Pitter, a young Purdue graduate working as a Manufacturing Engineer for Haynes, did a phenomenal job showing us the facilities.

He began with the north end of the facility where the smelting and refining operations took place. I was enamored by the number of options available merely to liquify and form the initial ingot. Open air smelting, argon oxygen decarburizers, vacuum induction melting, and electro slag remelting are among the techniques used by Haynes for ingot production here. We even had the opportunity to see them pour ingots from the decarburizer which poured four ingots of approximately five tons each.

Their forge was equally as impressive as the smelting equipment. A giant oven holding sections of ingots heated to 2800F. These pieces would be taken out of the oven and extruded by a massive power hammer. A machine called a manipulator moved these giant sections of metal, and the process for doing so reminded me a lot of how we extruded round stock in a blacksmithing club I participated in. Moving forward, we were able to view some of the homogenizing and annealing processes as well as their 3-high mill. The ovens near the mill were massive, and so hot that they glowed orange. I could feel the heat from about 40 feet away. The mill was just as impressive, with platforms that would rise and fall to catch the piece of plate coming through the working rollers. The process went smoothly and quickly with only a few passes between reheats of the material. I imagine that two reasons for this are 1) the large surface area causes the piece to drop in temperature quickly, and 2) there are concerns about overworking the material.

The southern campus was quite sprawling. We first visited the 4-high mill which was rolling hot coils at the time. The operator controlling the machine had a multitude of knobs and switches under his command, but he ran the process with speed and finesse, meticulously acquiring data throughout the process. Next, we visited the finishing line, which removed oxidation from the surface of the material through a series of processes like pickling, which involved acids, and hydrogen burners. The resulting materials were shiny coils of complex alloys that were then inspected for defects along the length of the coil. We even got to see another smaller mill that could roll these sheets thinner after finishing. The working rollers were quite small according to Quentin and Dr. Gildemeister because of the amount of force they needed to apply to the material. And while these rollers were quite hard, they needed to be changed often due to the hardness of the materials the rollers were working on.

Our final stop was at the lab where new alloys were tested and samples of materials currently in production were analyzed. As I learned on my visit, the world of materials covers a vast range of length scales, from angstroms up to tens or even hundreds of meters. Accordingly, their lab analyzed these materials at various levels to ensure a quality result throughout. I even had the opportunity to view some samples under a powerful microscope, learning about banding and carbides in the process.

Overall, my visit was both a fantastic educational experience and a fascinating time to see the mix of industrial power and human ingenuity required to provide materials that our world depends on. This tour gave me a new appreciation for materials and has given me a desire to learn more about the complexities of materials selection so I can be better prepared for my time in industry.

Brenden O'Kane, Technical Analyst