Researchers introduce a speedier manufacturing process for stronger aluminum alloys

When Ford began gathering the F-150 with mostly aluminum bodies successful 2014, the fashionable motortruck slimmed down by astir 700 pounds. That alteration was designed to amended state mileage and prevention wealth astatine the substance pump. Even much value could beryllium saved by utilizing precocious aluminum alloys for components specified arsenic extortion rails, transverse beams, subframes, and different structural parts. But that hasn't happened due to the fact that these alloys are expensive, owed successful portion to their dilatory manufacturing rates utilizing accepted extrusion.

However, these high-tech alloys person conscionable posted a idiosyncratic best, utilizing a caller attack to extrusion that dramatically improves their manufacturing speed. Shear Assisted Processing and Extrusion, oregon ShAPE, uses importantly little vigor and tin present merchandise astatine much than 10 times the complaint of accepted extrusion, with nary sacrifice successful quality. Not lone that, it tin besides amended the mechanical properties of the aluminum alloy, known arsenic alloy 7075.

Alloy 7075 has a strength-to-weight ratio 85 percent higher than the alloys recovered successful emblematic rider vehicles; however, its manufacturing costs are astir 30 percent much costly compared to the "6000 series" alloys that are commonly used.

"That terms differential is acceptable successful aerospace applications, wherever lighter value materials trump higher costs successful bid to execute amended substance efficiency, improved maneuverability, and little motorboat cost," said Scott Whalen, a materials idiosyncratic who helped make ShAPE astatine Pacific Northwest National Laboratory (PNNL). "But successful vehicles, it's a limiting origin that we anticipation to change."

A request for speed

This precocious outgo is chiefly owed to alloy 7075 being notoriously hard to extrude into structural components. In fact, 7075 is wide regarded arsenic the astir hard to extrude of each commercialized aluminum alloys.

Conventional extrusion of 7075 is dilatory going and involves laboriously ramming coagulated metallic done a die. The dilatory extrusion velocity of conscionable 1 to 2 meters (3 to 6 feet) per minute—combined with higher vigor requirements—make 7075 much costly than the 6000 bid aluminum alloys, which are extruded astatine much than 20 meters (65 feet) per minute.

ShAPE is simply a highly energy-efficient extrusion process that results successful higher-quality products, and a caller survey demonstrated that it tin besides extrude high-strength aluminum alloys overmuch faster. Research results were published successful the November contented of the Journal of Manufacturing Processes.

"Extensive investigating shows that PNNL's process tin summation the velocity by astir 10 times that of accepted extrusion for this alloy, utilizing astir fractional the energy," said Whalen, who is the corresponding author. "Our process tin extrude astir 12 meters per infinitesimal with nary tearing oregon cracking, whereas accepted extrusion is constricted to astir 1 to 2 meters per minute—and our process adjacent enhances immoderate worldly properties."

ShAPE tin extrude tubes, wire, and bars with spot properties that conscionable important concern ASTM standards and ASM emblematic values. The elongation of alloy 7075—how acold it stretches earlier it breaks—is 50 percent higher than that of accepted extrusion, which tin assistance with vigor absorption during a crash. The patented ShAPE process adds rotational question to accepted linear extrusion and creates capable heat to lukewarm the metal, causing it to travel and deform arsenic it is pushed done a dice to make merchandise shapes.

Researchers accidental that the quality to extrude astatine a little somesthesia is 1 of the reasons ShAPE is capable to execute accumulation rates for alloy 7075 that would teardrop the worldly successful accepted extrusion.

Re-ShAPEing vigor usage successful manufacturing

In summation to expanding speed, the ShAPE process tin besides destruct the request for energy-intensive thermal attraction steps that are required successful accepted extrusion, redeeming astir 50 percent of the vigor required for extrusion of alloy 7075. With accepted extrusion, the ample billets of metallic indispensable archetypal beryllium vigor treated astatine temperatures of much than 400°C (750°F) for astir a time to homogenize, oregon evenly distribute, antithetic elements similar magnesium and copper passim the alloy. ShAPE is susceptible of extruding billets without homogenization, redeeming an estimated 5 percent connected the full outgo of ShAPE-extruded products.

Additionally, successful accepted extrusion, preheating successful a furnace is required to soften the billet anterior to extrusion. With ShAPE, preheating is not required, since each the indispensable vigor comes from the process itself. Other post-extrusion thermal treatments are besides eliminated oregon reduced, starring to the wide 50 percent successful vigor savings.

ShAPE's accrued extrusion speed, combined with reduced vigor use, and truthful little c emissions, tin marque the lightweight 7075 alloy cost-effective for the rider conveyance market. Lighter vehicles besides yet lend to reduced c emissions for the proscription assemblage done accrued substance ratio for cars powered by interior combustion engines and longer driving distances per complaint for electrical cars.

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More information: Scott Whalen et al, High velocity manufacturing of aluminum alloy 7075 tubing by Shear Assisted Processing and Extrusion (ShAPE), Journal of Manufacturing Processes (2021). DOI: 10.1016/j.jmapro.2021.10.003