Ce孕育剂作用下的Al-20%Mg2Si复合材料微观组织和力学性能的变化规律

Change of Microstructure and Mechanical Properties of Al-20%Mg2Si Composites With Ce Inoculation

研究了Ce孕育剂对原位内生工艺制备的Al-20%Mg2Si复合材料微观组织和力学性能的影响及其作用机理.结果表明,Ce孕育剂能够有效改善Al-20%Mg2Si复合材料的晶粒尺寸、组织形貌及其分布规律.添加Ce的质量分数由0增至1.2%时,增强相Mg2Si颗粒的尺寸先减小后增大,同时复合材料的各项力学性能指标(极限拉伸强度UTS、断裂伸长率BE和维氏硬度HV)也先提高后降低.当Ce孕育剂添加质量分数为0.6%时,Al-20%Mg 2Si中增强相Mg 2Si的组织形貌最好,分布最均匀,细化效果也最明显,同时各力学性能指标达到极值,UTS由157.9 MPa提高到200.9 MPa,BE由2.96%提高到了3.91%,HV由145.2 MPa提高到184.8 MPa.

The microstructure and mechanical properties of Al-20%Mg2Si composites fabricated by in-situ process and modified by Ce inoculation were studied.The results show that the crystal size,morphology and distribution of can be modified by Ce inoculation effectively.When the mass fraction of Ce inoculation was added from 0 to 1.2%,the particles size of reinforcement phase Mg2Si decreases firstly then increases;but the ultimate tensile strength(UTS),breaking elongation(BE)and Vickers hardness(VH)increase firstly then decreases.When the amount of Ce inoculation approaches 0.6%,themorphology is the most perfect;the distribution is the most homogeneous;and the effect of refinement is the best.At the same time,the mechanical properties of Al-20%Mg2Si compositesare the best.The UTS increases to 200.9 MPa from 157.9 MPa;the BE increases the value from 2.96%to 3.91%;and the VH increases form 145.2 MPa to 184.8 MPa.