Shear Assisted Processing and Extrusion (ShAPE™) allows creation of wire, bar, and tubular extrusions that show significant improvement in material properties; for example, magnesium extrusions have been manufactured with unprecedented ductility (how far the material can stretch before it breaks) and energy absorption (how much energy can be absorbed during compression of a tubular extrusion) over conventional methods.
The technology is part of PNNL’s suite of Solid Phase Processing (SPP), an approach to metals manufacturing that can be better, cheaper, and greener than melt-based methods typically associated with metals manufacturing.
In ShAPE, a canister holding feedstock material — such as metal powder, flake, or billet — is forced into a rotating die. Frictional heating is generated at the interface between the feedstock material and die, softening only the material being extruded and eliminating the need for feedstock pre-heating or application of external heat used in conventional extrusion. Spiral grooves on the die face feed the material inward toward the extrusion orifice, which greatly reduces the force required during extrusion.
As an example, using ShAPE, nano-structured aluminum powder can be extruded directly into round bars using 50 times less force and much lower power consumption than conventional extrusion, while achieving twice the ductility. Costly and time-consuming steps required by conventional powder processing are entirely eliminated. The lower force and power enable substantially smaller production machinery.
With an extrusion ratio of 200:1 demonstrated for magnesium, ShAPE achieves in a single pass what would take multiple passes with conventional extrusion. The technology enables control over grain refinement and microstructure orientation in extrusions, which is not possible with other extrusion processes. In addition, magnesium extrusions made by ShAPE do not require costly rare earth elements to produce extrusions with sufficient ductility and energy absorption for use in some structural automotive applications (e.g., automobile bumpers), allowing more affordability in mass production.
ShAPE could be a viable method for the production of creep-resistant steels that could be used for heat exchangers in the electric power industry, and high-conductivity copper and advanced magnets for application in electric motors. It has also been used to produce high-strength aluminum rods with application in the aerospace industry. In yet another potential application, ShAPE shows promise as a method to produce semiconducting thermoelectric materials.