稀土钕对亚共晶铝硅合金组织及性能的影响

Effect of Rare Earth Element Nd on the Microstructures and Properties of Hypoeutectic Al-Si Alloy

摘要: 以中间合金的方式向亚共晶铝硅合金ZL101中添加不同含量的稀土钕进行变质处理, 研究了变质前后合金的组织、力学性能、拉伸断口形貌及物相组成。结果表明: 稀土钕对ZL101合金具有变质作用, 随钕含量的增加合金的硬度、强度及伸长率均先升后降, 钕添加量为0.3%时变质效果最佳, 合金硬度、抗拉强度及伸长率分别达到72 HBS, 190 MPa, 2.9%; 添加钕后合金拉伸断口中有韧窝出现; 钕含量达到0.4%时, 合金中生成的化合物相为Al8Si8MgNd2。

Abstract: Different contents of Nd were added into the hypoeutectic Al-Si alloy ZL101 in the form of master alloy for modification. The microstructure, mechanical properties, tensile fracture morphology and phase composition of alloys before and after being modified were investigated. The results indicate that ZL101 alloy was modified by the addition of Nd; the hardness, tensile strength and elongation of the modified alloy were increased first and then decreased, the optimum mechanical properties with hardness of 72 HBS, tensile strength of 190 MPa and elongation of 2.9% were achieved when 0.3wt% Nd was added into the alloy; and dimples were observed in the tensile fracture morphology; Nd compound phase, Al8Si8MgNd2, formed when the content of Nd was 0.4wt%.