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，即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，这一比例约为80%。根据加拿大卫生部的数据，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高利润的柴油发动机取得成功。令人惊讶的是，很少有法律控制沉重，浓厚的黑烟对人们健康的影响。对烟气进行彻底的净化（NOx捕集器、颗粒过滤器等）似乎不足以显著控制其负面影响。然而，发动机的大规模缩小是在显着减少柴油发动机污染方面向前迈出的一步。尽管如此，如果没有创新的热处理方法，以及对其对铝合金微观结构影响的全面了解，就无法实现这样的挑战。该项目旨在接受这一挑战，使用数值多尺度方法加上强大的实验过程。换句话说，它旨在准确地理解热处理的优点和缺点，特别是用于制造气缸盖的淬火工艺。研究涉及Al 2Cu颗粒的形核-生长-粗化的伴随模型。位错与析出相的相互作用被包含在模型中，这将有助于确定铝合金的屈服应力。然后将该模型实施到有限元软件中，以便在工业网格上执行计算。结果将通过实验方法进行验证，其中包括显微镜分析和机械测试。该项目由一个国际团队领导，参与者包括拉瓦尔大学、魁北克大学、魁北克省冶金中心、力拓铝业公司和Montupet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.