Development of new grain refiners for aluminum alloys for engine block applications

几十年来，技术进步一直受到材料科学进步的推动。例如，在20世纪70年代和80年代，用较轻的铝部件代替汽车中的铁部件，导致了立即的性能和燃料经济性的提高。最近，环境保护局和环保部。美国《交通运输法》规定，到2025年，汽车制造商必须减少温室气体排放，并将燃油经济性提高50%以上，否则将面临经济处罚。人们普遍认为，这样一个巨大的改善是可以实现的车辆混合，或车辆重量减少。这两种方法都面临挑战：1）混合动力成本高，增加了车辆重量，2）现有的轻质合金制造工艺正在接近技术极限，进一步的进步成本高昂。在这项Engage资助中，来自不列颠哥伦比亚省大学和加拿大Nemak的研究人员将探索一种创新的多工艺方法，以克服与现有超轻高强度铝（Al）合金制造方法相关的限制。具体而言，先进的粉末冶金工艺（放电等离子烧结，SPS）将与传统的金属铸造工艺相结合，以开发新型的可铸造铝合金。利用SPS技术，将纳米和微米级陶瓷增强体与Al基粉末混合并烧结成圆片。随后将烧结的圆盘在铸造过程中加入到液态铝合金中，导致铝基体在熔体中溶解，随后在熔体中均匀释放陶瓷增强材料。增强体将用于同时增强室温强度（通过晶粒细化和共晶的改性）和抗蠕变性（通过晶界钉扎）。这种新颖的方法预计将克服几个关键的挑战（例如，颗粒沉淀、浮选或氧化）。实验工作将在UBC实验室以及Nemak Canada温莎铝厂（安大略）进行。

For decades, technological advancements have been driven by the progress in materials science. For example,the substitution of iron components in automobiles with lighter aluminum components during the 1970's and80's resulted in an immediate performance and fuel economy enhancement. Recently, the EnvironmentalProtection Agency and the Dept. of Transportation in USA mandated automakers to decrease greenhouse gasemissions and improve fuel economy by over 50% by 2025, otherwise face economic penalties. It is generallyaccepted that such a drastic improvement is achievable either by vehicle hybridization, or by vehicle weightreduction. Both approaches face challenges: 1) Hybridization is costly and adds weight to vehicles, and 2)Existing manufacturing processes for lightweight alloys are approaching technological limits and furtheradvancements are costly.In this Engage grant, researchers from the University of British Columbia and Nemak Canada will explorean innovative multi-process approach to overcome the limits associated with existing manufacturing methodsfor ultralight high-strength aluminum (Al) alloys. Specifically, an advanced powder metallurgy process (SparkPlasma Sintering, SPS) will be combined with a traditional metalcasting process to develop novel castable Alalloys. Using SPS, nano- and micro-scale ceramic reinforcements will be blended with Al matrix powder andsintered into a disc. The sintered discs will be subsequently added to liquid Al alloys during casting, resultingin dissolution of the Al matrix within the melt, followed by a homogeneous release of the ceramicreinforcements inside of the melt. The reinforcements will serve to simultaneously enhance the roomtemperature strength (via grain refinement and the modification of eutectics) and creep resistance (via grainboundary pinning). This novel approach is anticipated to overcome several critical challenges (e.g., particlesettling, flotation or oxidation) associated with current treatment methods for liquid Al alloys. Experimentalwork will be carried out at UBC laboratories as well as at Nemak Canada Windsor Aluminum Plant, Ontario.