The Need

Friction stir extrusion (FSE) is a variation of friction stir processing that enables the hot extrusion of metal profiles from billet or other precursor material without preheating. This process saves significant thermal energy over conventional metal extrusion processes and can impart favorable microstructures to the end products. However, current FSE technologies have significant limitations regarding the high starting forces/torques required, which increase spindle requirements and restrict the materials that can be effectively processed.

The Technology

Researchers at The Ohio State University have developed a streamlined FSE die design approach that optimizes the metal flow, resulting in reduced force and torque requirements. A tapered plug with small interference can be used at the end of the mandrel to assist in initial heat generation. The angled die increases the die-to-metal contact area during the process to enhance heat generation and transfer. Furthermore, the angled die promotes more efficient metal flow during extrusion, which improves extrusion rates and reduces spindle loads/torques.

Commercial Applications

• Lightweight automotive frames for commercial and military applications
• Advanced structures for aircraft and spacecraft
• Metallurgical processing and manufacturing
• Enhanced industrial applications
• Metallic, multi-metallic, and MMC material system applications

Benefits/Advantages

• Increases heat generation, which improves process and thermal efficiencies
• Optimizes metal flow and reduces load/torque requirements
• Can be configured for either forward extrusion or backward extrusion
• Can produce stronger, lighter, and more ductile structural frames, resulting in improved fuel efficiency and structural performance
• Refined grain structure for improved performance over conventional metal extrusion processing

Patents

• U.S. Patent Application No. 18/478,381