Hot Extruded Superalloy Profiles for Elite Motorsport
A customer working at the top level of motorsport developed a next generation titanium based superalloy and needed a forming solution for it. The requirement went beyond dimensions, because the process itself had to improve the properties of the material rather than merely give it a shape. Conventional forming technologies could not handle the alloy, and the section required was a simple circular one, a geometry rarely associated with hot extrusion. Montanstahl developed a multi-stage extrusion process with tightly defined parameters that met the required dimensions and, at the same time, tailored the microstructure of the finished bar.
Aerospace Technology Moving Onto the Racetrack
Extraordinary operating conditions demand extraordinary materials, and the environment inside a racing engine is close to the limit of what any alloy tolerates. Engine speeds reach 18,000 rpm, combustion temperatures exceed 1,000 degrees Celsius, and the gases circulating through the system are chemically aggressive. Components have to survive that combination while weighing as little as possible, which is why technologies developed for aerospace have progressively migrated into high performance automotive and motorsport applications. The customer responded by developing a next generation superalloy of their own, and then looked for a partner able to form it. What made the brief unusual was the expectation attached to the process. Shaping the bar was necessary but not sufficient, since the forming operation was also expected to improve the already exceptional properties of the material, treating the process as part of the metallurgy rather than a step that follows it.
A Narrow Process Window and an Unexpected Geometry
Conventional forming technologies could not be applied to this superalloy at all, because the properties that make it valuable in service are the same ones that make it resist deformation. The process windows available were extremely narrow and demanded precise control, since temperature and pressure had to stay inside a band where the material deforms without cracking or losing its structure. Any deviation during forming would have caused failure, which removes the margin normally used to absorb variation between billets or between production runs. The geometry added a further twist. Hot extrusion is usually chosen for complex profiles with undercuts and elaborate cross-sections, as described in our guide to steel and stainless steel hot extrusion, while here the requirement was a simple round section. The reason for the choice was not the shape but what happens to the material while it is being formed.
Application Context
The answer was a multi-stage hot extrusion process with precisely defined parameters, developed so that each pass keeps the material inside its narrow forming window. The result met the dimensions the customer specified and went further, because the deformation sequence was designed to refine the grain structure of the alloy, so the finished bar leaves the line with mechanical properties beyond those of the starting material. Aerospace derived technology reaches the racetracks of the world through a component that looks unremarkable from the outside, which is a useful reminder that progress often sits below the visible surface of a part. Hot extrusion is available across the Montanstahl group in carbon steel, stainless steel, nickel base alloys, titanium and superalloys, with capacity in Switzerland, Germany and at Siderval in Italy, and without minimum quantities, so even a single prototype bar can be produced. Questions on alloys, dimensional limits and tolerances are answered in the technical Q&A.