TSE: Collaborative Research: Environmentally Benign Manufacturing - Casting by Design

这项国家科学基金会和环境保护局的可持续环境技术项目提出了一种新技术，使熔融金属能够在单一步骤中连续浇注，达到设计者的规格。贝塞默(Bessemer)的愿景(1865年)将原材料直接固化为最终产品，而不需要下游加工步骤(轧制、退火)，现在可以实现薄平板产品，以显著的环境优势。例如，仅在美国，一步浇铸铝箔就可以每年减少向大气排放25万吨二氧化碳。在减少制造浪费方面节省的每一公斤铝，都会转化为这家耗能巨大的冶炼厂节省的电力。这项技术是基于控制以前无法控制的长度刻度。这一想法是激光和单辊旋转铸造技术的结合。这种激光器提供了一种独特的方式，将能量带入熔融金属和基材之间的接触区。接触区是一个条件恶劣的区域，通常不适合机械入侵。成功的设计铸造，或可调铸造，将使用激光能量来控制产品质量。一种方法是通过在接触区之前施加温度梯度来调节衬底。喷墨打印中的灰阶是由相同大小的墨点的间距和排列产生的。以大致相同的方式，将根据热点的排列和间距来确定拟议的梯度。激光加热会在细小尺度上诱导出热点。该项目将在减少对环境的影响和能源消耗方面产生重大的社会效益，并为工业提供更好的缩小加工要求。

This National Science Foundation and Environmental Protection Agency Technologies for a Sustainable Environment project proposes a new technology to enable continuous casting of molten metals, in a single step, to the specifications of the designer. Bessemer's vision (1865) of solidifying raw material directly into final product, without downstream processing steps (rolling, annealing), may now be realized for thin flat product, to marked environmental advantage. To cast aluminum foil, e.g., in a single step, would reduce CO2 emissions to the atmosphere by 250,000 tons per year, in the US alone. Every kilogram of aluminum saved in reducing manufacturing waste translates into electricity saved at the energy-hungry smelter. The technology is based on controlling length scales previously inaccessible to control. The idea is a marriage between laser and single-roll spin casting technologies. The laser offers a unique way to bring energy into the zone of contact between molten metal and substrate. The contact zone is a region of adverse conditions, generally inhospitable to mechanical intrusion. Successful casting by design, or tunable casting, will use laser energy to manipulate product quality. One approach is to condition the substrate by imposing thermal gradients before the contact zone. Grey-scales in ink-jet printing are produced by the spacing and arrangements of ink dots of the same size. In much the same way, the proposed gradients will be established with arrangements and spacing of hot spots. Laser heating will induce the hot spots at fine scales. This project will have significant societal benefits in reducing environmental impact and energy consumption, as well as providing improved scaled-down processing requirements for industry.