STTR Phase I: Forging of Fine Grained Semi-Solid Aluminum Billets Created "in-Situ" from Molten Metal

This Small Business Technology Transfer (STTR) Phase I project will develop a forging process that combines the latest technologies of ultrasonic processing of materials and rapid infrared heating (RIH) of forgings. This project will demonstrate the feasibility of an enabling technology for the semi-solid forging complex shaped components of high strength aluminum alloys that are difficult to cast. The project will make semi-solid forging stock with high solid fractions directly from molten alloy immediately in advance of the semi-solid blanks prior to a forging operation could result in a significant cost and energy savings. The use of high intensity ultrasonic vibration techniques will produce smaller grain sizes than can now be achieved with available semi-solid processes, a significant improvement compared with rheocasting/thixoforming. With high solid fractions, the forging stock will have a "mushy" texture, allowing more effective material handling than typical semi-solid blanks. The small grain size achieved will make metal alloys more resistant to hot tearing and other defect formation. The forging of a "mushy" feed stock will reduce porosity and allow high strength alloys prone to hot tearing to be processed. A new RIH technology will be used to preserve the small grain size obtained during semi-solid/forging processes. The broader impacts of this technology could lead to a breakthrough in SSM forging and could increase the competitiveness of the U.S. forging industry in the global market. The technology can be used to make high strength lightweight components to replace heavy components for automotive, aviation, and defense application, leading to significant energy savings and cost savings.