The Microstructure And Properties Of Recycled ADC12 Modification By The Mixed Rare Earth

The non-ferrous mineral resources around the world are limited and the majority of them are facing the crisis of exploitation done in the 21st century because limited storage in the earth. Therefore, it is better for us to turning up the attention to the aluminum recycling industry. The mass production of recycled aluminum can slow down the exploitation rate on the primary aluminum and reducing the pressure of the environment. The low technical level and production management level of the aluminum recycling industry in China is still far behind some developed countries, this result in some of the high quality recycled aluminum alloys did not have a good use and which are forced to use downgrade. However, the Rare Earth usually be used as impurity removal agent and modifier in the alloys to improve the properties of alloys. In this paper, the way to prepare La-Ce-Al alloy and the effects of the rare earth addition on microstructure and properties of recycled ADC 12 alloy are studied. However, the effects of cooling rate to the recycled ADC 12 alloy also studied in this paper. For the purpose of the further study of the modification effect and the modification mechanism of rare earth add to the recycled ADC 12 alloy, the research depend on the microstructure, room temperature mechanical properties testing, SEM, hardness testing, XRD testing, and DSC testing.The results showed that use the mixed melting method can successfully prepared La-Ce-Al alloys under the experimental conditions. The addition of the La-Ce-Al alloys to the recycled ADC 12 alloy will improve the properties of the alloy, while the addition is 0.3(wt)%, the tensile strength and micro-hardness of the alloy reached the highest level. When adding the rare earth elements, the porosity, a-Al and Si size are significantly reduced in the ADC 12 alloy. And the adding amount of rare earth elements reached 0.3%, the modification effects is the best. The SDAS and average length of eutectic silicon have different sensitivity to the cooling rate. When there is no rare earth adding to the alloy, the SDAS have the highest sensitivity to the cooling rate. However, when the rare earth addition amount is 0.1%, the SDAS have the highest sensitivity to the cooling rate compared to other addition amount. But there is no significant regularity of the eutectic silicon average length to the sensitivity of the cooling rate. When the addition amount of the rare earth is 0.3%, the average length of the eutectic silicon is most affected by the cooling rate, which has the highest sensitivity to the cooling rate.