摘要
采用铸锭冶金法制备了Al-0.9Mg-0.6Si-0.7Cu-xSc合金,利用光学显微镜、扫描电镜和拉伸试验机研究了Sc元素对Al-0.9Mg-0.6Si-0.7Cu合金微观组织、力学性能和断口形貌的影响。结果表明,添加微量Sc形成的AlMgSiCuSc析出相可作为异质形核核心,显著细化铸态组织;在Al-Mg-Si-Cu合金中添加0.3wt%Sc,能强烈钉扎位错和亚晶界,有效阻碍固溶处理过程中的再结晶,从而提高合金的抗拉强度、屈服强度和延伸率;且Al-0.90Mg-0.59Si-0.70Cu-0.3Sc合金断口的韧窝数量较多、分布均匀,断口形貌为典型的韧性断裂。
Al-0.9Mg-0.6Si-0.7Cu-xSc alloys were produced by ingot-metallurgy method.The effects of the Sc addition on the microstructure,the mechanical properties and the fracture morphologies of the Al-0.9Mg-0.6Si-0.7Cu alloy were investigated by means of optical microscope,scanning electron microscopy and tensile testing machine.The results show that trace Sc can fine grains of the as-cast alloy by precipitating AlMgSiCuSc phase from the melt during solidification as heterogeneous nuclei.The dislocation and subgrain boundaries are strongly pinned,and the recrystallization of the alloys is restrained during solid solution treatment by adding 0.3wt% Sc in Al-Mg-Si-Cu alloy,thus the alloy containing 0.3wt% Sc exhibits remarkable higher tensile strength,yield strength and elongation.Compared with the alloy without Sc addition,the Al-Mg-Si-Cu alloy with 0.3wt% Sc has much equiaxed dimple on the fracture surface,and the distribution of dimple is uniform,so the fracture morphology is typical ductile fracture.
出处
《塑性工程学报》
CAS
CSCD
北大核心
2015年第3期107-110,143,共5页
Journal of Plasticity Engineering
基金
教育部科学技术研究重大资助项目(311025)
