SBIR Phase I: Novel low temperature, in-situ processing route for high performance, light weight structural materials

这项小型企业创新研究第一阶段项目涉及在轻质镁合金加工中使用纳米结构化学品以实现高性能应用。假设通过固相混合和原位反应，将具有多种硅醇功能的多面体低聚硅氧烷（POSS）等反应性纳米结构化学物质添加到镁合金中，以实现高温下的微观结构稳定性，从而显著提高镁合金的性能。这种原位处理路线是通过创造一种环境来实现的，在这种环境中，表面金属离子被酸或通量去除氧化物并带正电，与POSS中的Si-OH基团结合。末端反应导致在晶界附近化学和热稳定的高浓度纳米级Si-O笼化合物的化学附着。这些纳米笼状化合物为防止金属间化合物（IMC）的过度生长和延缓晶粒间的高温运动提供了障碍，从而保证了镁合金组织的稳定性。原位工艺克服了在金属基体中分散纳米颗粒的常见问题，在金属基体中纳米颗粒可能发生团聚和聚类。由此产生的镁合金将被证明在环境和高温下都有更好的使用和机械性能。该项目的更广泛的影响/商业潜力将是显著提高结构Mg组件的性能，使其在汽车和航空航天工业中得到广泛应用。汽车和航空航天工业在减少燃料消耗和有害排放方面面临着越来越大的压力。减轻车辆和飞机的整体重量是实现这些目标的关键，而镁合金的低密度通常是一个可行的方案。然而，镁的广泛应用受到其相对较差的机械性能和高温蠕变性能的限制。该项目的目标是通过POSS加工生产适用于结构应用的高强度，抗蠕变的镁材料。含有高浓度纳米级Si-O笼状化合物的材料将用作铸造操作中的主合金，以生产大型网状部件。开发的制造技术将为结构汽车和航空航天部件制造商提供相对于国外竞争的成本优势。

This Small Business Innovation Research Phase I project relates to the use of nano-structured chemicals in the processing of light-weight magnesium (Mg) alloys for high performance applications. It is postulated that reactive nano-structured chemicals such as polyhedral oligomeric silsesquioxane (POSS) with multiple silanol functionalities will be added to Mg alloys by solid phase mixing and in-situ reaction to achieve microstructure stability at higher temperatures leading to a significant performance enhancement for Mg alloys. This in-situ processing route is achieved through creating an environment where surface metal ions, with oxides removed and positively charged by acid or flux, bond to Si-OH groups in POSS. The end reaction results in chemical attachment of high concentrations of nanoscale Si-O cage compounds that are chemically and thermally stable near the grain boundary. These nanoscale cage compounds provide obstacles to prevent overgrowth of intermetallic compounds (IMC) and retard the motions between grains at high temperatures for microstructure stability of Mg alloys. The in-situ process overcomes the common problem of dispersing nanoparticles in a metal matrix where agglomeration and clustering of nanoparticles can occur. The resulting Mg alloys will be demonstrated to have improved service and mechanical properties at both ambient and elevated temperatures. The broader impact/commercial potential of this project will be to significantly improve performance of structural Mg components enabling widespread application in the automotive and aerospace industries. The automotive and aerospace industries are under ever-increasing pressure to reduce both fuel consumption and harmful emissions. Reducing the overall weight of vehicles and aircraft is key to achieving these goals and magnesium alloys, with their low density, can often be a viable proposition. However, the widespread use of magnesium is limited by its relatively poor mechanical and high-temperature creep properties. The project goal is to produce high-strength, creep-resistant magnesium material suitable for structural applications by POSS processing. Material with high concentrations of nanoscale Si-O cage compounds will be used as a master alloy in casting operations to produce large net shaped components. The manufacturing technology developed will provide a cost advantage over foreign competition for manufacturers of structural automotive and aerospace parts.