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

这个小型企业技术转移(STTR)第一阶段项目将开发一种结合了材料超声波处理和锻件快速红外线加热(RIH)的最新技术的锻造工艺。本项目将论证高强度铝合金难于铸造的复杂形状零件半固态锻造技术的可行性。该项目将在锻造操作之前，在半固态坯料之前直接从熔融合金中制造具有高固体分数的半固态锻件坯料，从而节省大量成本和能源。使用高强度超声波振动技术将产生比现有半固态工艺更小的晶粒尺寸，与流变铸造/触变成形相比，这是一个显著的改进。与典型的半固态坯料相比，具有高固体分数的锻造坯料将具有“糊状”质地，从而允许更有效的材料处理。所获得的细晶尺寸将使金属合金更耐热撕裂和其他缺陷的形成。“糊状”原料的锻造将减少气孔率，并使易热撕裂的高强度合金得以加工。一种新的RIH技术将被用来保存半固态/锻造过程中获得的细小晶粒度。该技术的更广泛影响可能导致SSM锻造方面的突破，并可能增加美国锻造行业在全球市场上的竞争力。该技术可用于制造高强度轻质部件，以取代汽车、航空和国防应用的重型部件，从而显著节省能源和成本。

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.