Intellectual Property Office

Non-Confidential Disclosures

“Electrically Assisted Metal Forging Process”

PSU Inv. Disc. No 2007-3314
Download a PDF of this description

Figure 1: Aluminum Stress-Strain Curves

Keywords

Metal forging, rolling, extrusion

Inventors:

John T. Roth

Links:

http://www.ipo.psu.edu
http://www.erie.psu.edu/academic/engineering/faculty/jtr11

Background:

During forming of metals using various bulk deformation processes, the magnitude of force required to perform a desired deformation is a significant factor in terms of the manufacturing of parts. Generally, as the force necessary to deform a given material increases, larger equipment must be utilized, stronger tools and dies are required, tool and die wear increase, and more energy is consumed in the process. All of these factors increase the manufacturing cost of a given component. These deformation forces are often decreased by working the metals at elevated temperatures, but this still requires significant energy use in the form of heat. Therefore, any way to decrease the force and/or heat required for deformation and/or increase deformation would have a significant impact on many manufacturing processes.

Invention description:

The present research shows that the flow stress necessary to deform certain metallic materials can be decreased when an electrical current is present in the material while undergoing deformation. Further, it has been proven that not all of the effects on the properties can be explained through resistive heating, implying that the electron flow through the metal is actual causing changes to the mechanical properties as well. For example, it has been shown that when an electron flow is present during the compression of 6061-T6511 aluminum, the yield stress and flow stress are dramatically decreased without the excessive heating that is needed for hot-working. This then provides a viable improvement over hot-working, since greater force reductions can be obtained without any of the drawbacks that are associated with hot-working. Figure 1 shows stress-strain curves for 7075 T6 aluminum samples tested at various current densities. This material is more brittle than 6061 aluminum and fractured prior to reaching the final height under baseline (0 A/mm2) conditions. As the current density increased, the corresponding stress values decreased and the strain at cracking also increased. Moreover, at the highest current densities [46.3, 54.4, and 90.1 A/mm2], the sample did not fracture during the normal course of the test. This test also shows that a region developed after yield where the stress dramatically decreased as strain increased (bottom curve) requiring very little stress to continue deformation.

Advantages:

• Decrease machine wear and energy use during metal forging processes
  
• Reduced temperature metal forging
  
• Allows significant increases in total deformation to be achieved using extremely low forces
  

Contact:

Bradley A. Swope
Sr. Technology Licensing Officer
Intellectual Property Office
113 Technology Center
The Pennsylvania State Univ.
University Park, PA 16802-7000
Phone: (814) 863-5987
Fax: (814) 865-3591
E-mail:bradswope@psu.edu