To Increase The Impact Ductility Of Aluminum Alloy Used In The Doughnut

With the increasing demand of energy conservation and more strict laws and regulations of safety and environmental protection, To lighten the car's weight is more urgent. Aluminum alloy has so many merits such as light in weight, good ductility, good compactibility, appropriate price and high recovery rate, that it is important to lighten car's weight, decrease oil consume and environmental pollution, and improve serviceability. And these make aluminum alloy become the preferred material. To modify or manufacture more light and tough aluminum alloy tire has far-reaching impact on the automotive industry, based on the existing production technology and facility.Many car's tires are made of ZL101A alloy or A356(USA), and its ingredients like this: 6.5~7.0% Silicon, 0.25~0.45%Magnesium, small amount of copper and iron, and the rest is aluminum. There are some methods to improve impact ductility, such as modification, refining crystal grain, and scavenging. Modification and scavenging with argon are adopted in this article.Al-Si alloy mast be modified to alter its silicon phase and increase its mechanical property when content of Si is greater than 6%. The eutectic silicon assumes thick sheets and speculates before modified, and it makes alloy become fragile and ductility reduced. The purpose of modification is to alter the pattern and size of eutectic silicon phase, and to turn it into fine fibers and layered tablets.The experiment includes there steps. The rare-earth and strontium were added into the metamorphose alloy in exploratory experiment, but it wasn't succeed. So some of technological operations were adjusted in stability test, in another words, only the rare-earth was added in to alloy, and scavenged with argon after modification. The results show that impact ductility increased by 70%; The strength of extension increased by 83%; And the extensibility increased by 132%.The constitution diagram is also observed and photos are taked. It was found that the eutectic silicon assumes thick sheets and speculates before modified after observed and analysed those photos. Whereas, the eutectic silicon assumes fine fibers and layered tablets after the alloy was metamorphose and scavenged. These results show that the eutectic silicon is improved, and the crystal grain is refined. Therefore, the impact ductility is increased.