Predicting the mechanical properties of foundry aluminium alloys for high temperature applications

2012年6月，世界卫生组织（WHO）下属的国际癌症研究机构（IARC）将柴油发动机尾气列为对人类致癌的物质。这是基于充分的证据表明，接触与肺癌风险增加有关。在欧洲，超过50%的汽车使用柴油。在法国，这个比例大约是80%。据加拿大卫生部称，2007年，运输部门的排放量约占加拿大总排放量的27%。30多年来，汽车制造商一直依靠其利润丰厚的柴油发动机取得成功。令人惊讶的是，几乎没有法律控制又重又浓的黑烟对人们健康的影响。烟气的极端净化（氮氧化物捕集器、微粒过滤器等）似乎不足以显著控制其“负面影响”。然而，发动机的大规模小型化是在显著减少柴油发动机的污染向前迈出的一步。然而，如果没有创新的热处理技术，以及对其对铝合金微观结构的影响的全面了解，就无法实现这一挑战。这个项目开始接受这一挑战，使用数值多尺度方法结合强大的实验过程。换句话说，它的目的是准确地了解热处理的优点和缺点，特别是用于制造头部气缸的淬火工艺。该研究涉及到Al2Cu颗粒的成核-生长-粗化的同步建模。位错与析出相的相互作用也包含在模型中，这将有助于确定铝合金的屈服应力。然后将该模型实现到有限元软件中，以便在工业网格上进行计算。结果将通过实验方法进行验证，其中包括微观分析和力学测试。该项目由一个国际团队领导，包括拉瓦尔大学、齐库蒂米大学、齐库蒂米大学、齐库蒂米大学、齐库蒂米大学、加拿大铝业公司和蒙图佩公司

In June 2012, the International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO), classified diesel engine exhaust as carcinogenic to humans. This was based on sufficient evidence that exposure is associated with an increased risk for lung cancer. In Europe, more than 50% of the cars run on Diesel. In France, it is about 80%. According to Health Canada, in 2007, the transportation sector emissions represented about 27% of Canada's total emissions inventory. Car manufacturers have been coasting on the success of their highly profitable Diesel engines for more than 30 years. Surprisingly, very few laws were controlling the effects that the heavy, thick, black smoke was having on peoples' health. Extreme depollution of the fume (NOx traps, particulate filters, etc...) appears to not be enough to significantly control its' negative effects. However, the massive downsizing of the engines is a step forward in significantly decreasing the pollution of Diesel engines. Nonetheless, such a challenge can't be reached without an innovative thermal treatment, and a complete understanding of its impact on the microstructure of the aluminum alloy. This project sets out to take on this challenge, using a numerical multiscale approach coupled with strong experimental processes. In other words, it aims to accurately understand the benefits and the negatives of the thermal treatment, particularly the quenching process that is used to manufacture the head cylinder. The research involves the concomitant modeling of nucleation-growth-coarsening of Al2Cu particles. The interaction of the dislocations with the precipitates is included in the model and will help to determine the yield stress of the aluminum alloy. This model will then be implemented into a finite element software in order to perform computation on industrial meshes. The results will be validated by an experimental approach involving, amongst other things, microscopic analysis and mechanical testing. The project is led by an international team, involving Université Laval, Université du Québec à Chicoutimi, Centre de Métallurgie du Québec, Rio Tinto Alcan and Montupet S.A.