【摘要】 通过弯边变形,拉伸实验,OM,SEM和TEM观察等手段研究了不同浓度富Fe相粒子对Al-Mg-Si-Cu系合金板材弯边性能的影响规律.结果表明,随着富Fe相浓度增加,合金板材沿纵横向的弯边性能存在较大差异,不含富Fe相粒子的合金板材沿2个方向弯边变形180°后外表面粗糙度增加,处于中等浓度(含0.2%Fe)时沿2个方向弯边变形后均具有优异的外表面质量,但是随着富Fe相浓度的进一步增加(至0.5%Fe),合金板材沿横向弯边变形后在外表面出现微裂纹.虽然富Fe相粒子浓度增加对合金板材纵横向延伸率影响不大,但是拉伸断口、弯边和拉伸断裂后的侧表面组织均表明,不含富Fe相的合金板材弯边变形后外表面粗糙度增加与剪切带组织密切相关,而含有较高浓度富Fe相粒子的合金板材弯边变形后外表面出现的微裂纹与粗大富Fe相粒子的尺寸、形态以及分布状态密切相关.此外,根据不同浓度富Fe相粒子与合金弯边性能间的定量关系,提出了合金弯边变形后外表面粗糙度增加和微裂纹形成的模型示意图.更多还原

【Abstract】 The influence of Fe-rich phase particle with different contents on the bendability of the Al-Mg-SiCu alloys was investigated by means of bending and tensile tests, OM, SEM and TEM characterization. The results reveal that, with the increase of Fe-rich phase particle content, the bendability of the alloy sheets in the longitudinal and transverse directions was quite different, and the outer surface of the alloy sheets after bending of 180° along the two directions became much rough, especially along the transverse direction. When the Fe-rich phase concen-tration increased to the medium level(0.2%Fe), the quality of outer surface after bending was very good. With further increasing Fe-rich phase to the high level(0.5%Fe), micro cracks were produced after bending along the transverse direction. Although increasing Fe-rich phase concentration did not give a great effect on the elongation of the alloys in the two directions, according to the tensile fracture and microstructure in the slid surface of the specimen after bending or tension test, the roughening of outer surface of the alloy sheet without Fe-rich phase was closely related with the formation of shear bands, while for the alloy sheet with high concentration of Fe-rich phases, the formation of micro cracks after bending was mainly related with the size, morphology and distribution of coarse Ferich phases. In addition, based on the quantitative relationship between Fe-rich phase concentration and bendability of the alloy sheets, the models of outer surface roughening and micro cracks forming during bendingare proposed.更多还原