SBIR Phase I: Designing New Economical High-Temperature Aluminum Superalloys

这个小企业创新研究第一阶段项目涉及开发一种新型轻质铝高温合金，以取代汽车制动转子中较重的铸铁。刹车片有很大的市场，全球估计有100亿美元。在一辆普通轿车中更换四个铸铁制动转子将使其重量减轻约80磅，这意味着耗油量的显著提高和尾气排放的减少。由于新的美国企业平均燃油经济性（CAFE）规定，这些优势预计将对汽车制造商产生吸引力。如果成功的话，在更换周期内，新的铝高温合金可以占据制动转子市场2.5%的份额，相当于每年2500万个制动转子。改用铝合金制动转子的其他好处包括：(a)从制动表面快速散热；(b)更快的停车和加速，更好的汽车操控性；(c)由于采用铝，耐腐蚀性大大提高；(d)消除腐蚀产物（在铸铁转子上形成的锈导致制动时热量分布不均匀）。目前商用的轻质时效硬化铝合金在220摄氏度以上是不能使用的，因为强化沉淀会溶解。因此，铝合金在涉及高温的应用中没有广泛的商业用途；例如，汽车制动转子。第一种选择是含有0.15-0.30%重量钪的铝合金（含有耐热和抗粗化的Al3Sc沉淀）。另一种选择是带有陶瓷颗粒或纤维的铝基复合材料。然而，前者含有一种昂贵的元素（钪的价格与黄金相当），而后者分别涉及复杂而昂贵的加工路线，严重限制了它们的使用。第一阶段的目标是成功开发并申请新的专有合金成分和热处理工艺的专利，以生产能够在400摄氏度及以上的环境下持续数月的无sc铝高温合金，而不会显著损失强度。我们还将制造一个原型制动转子，以进一步证明这种材料。

This Small Business Innovation Research Phase I project involves development of a new class of lightweight aluminum superalloys to replace much heavier cast iron in automobile brake rotors. There is a large market for brake rotors, estimated worldwide at $10 billion. Replacing four cast iron brake rotors in a typical sedan will reduce its weight by about 80 pounds, which translates into significant improvements in gas mileage and reductions in tailpipe emissions. These advantages are anticipated to be compelling to automakers, because of the new U.S. Corporate Average Fuel Economy (CAFE) rules. If successful, the new aluminum superalloys can capture a 2.5% share of the brake-rotor market, equivalent to 25 million brake rotors per year, during the replacement cycle. Other benefits of the switch to aluminum alloy brake rotors include: (a) rapid heat dissipation from the brake surface; (b) faster stopping and acceleration, and better automobile handling; (c) much higher corrosion resistance due to the usage of aluminum; and (d) the elimination of corrosion products (rust which forms on cast iron rotors leads to inhomogeneous heat distribution during braking).Current commercial lightweight age-hardenable aluminum alloys are not useable above 220 degrees C because the strengthening precipitates dissolve. Thus, there is no widespread commercial usage of aluminum alloys for applications that involve elevated temperatures; e.g., automotive brake rotors. A first alternative is aluminum alloys containing 0.15-0.30% by weight of scandium (which contains heat- and coarsening-resistant Al3Sc precipitates). Another alternative is aluminum-matrix composites with ceramic particles or fibers. The former contain, however, an expensive element (scandium is comparable to gold in price) and the latter involve complicated and expensive processing routes, respectively, severely limiting their usage. The goal of Phase I is to develop successfully and patent new proprietary alloy compositions and heat treatment procedures to produce Sc-free aluminum superalloys able to sustain months of exposure at 400 degrees C and above, without a significant loss of strength. We will also manufacture a prototype brake rotor, in order to further prove out this material.