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以固溶—时效和固溶—大变形(压缩、ECAP)—时效加工的7085铝合金为实验对象,分别采用拉伸试验机、X射线衍射仪(XRD)和晶体微区取向分析技术(EBSD)对7085铝合金的拉伸性能、内部的位错密度、单元边界(小角度晶界)和晶粒边界(大角度晶界)进行研究,结合拉伸试验测得的屈服强度,定量计算强化项对不同状态下铝合金的强化贡献。结果表明,相比常规固溶—时效工艺,固溶—大变形—时效工艺加工的7085铝合金的拉伸强度从381.2MPa分别提升到475.6和543.3 MPa;位错强化显著提高,从零分别提高到107.4和180.6 MPa;小角度强化显著提高,从10.4 MPa分别提高到89.1和116.4 MPa。7085铝合金强度提高来源于材料内部的位错和小角度晶界;固溶后的大变形加速了时效,降低了时效沉淀强化。并且发现强烈塑性变形加工(ECAP)的强化效果高于传统塑性变形加工(压缩变形)的效果。
The 7085 aluminum alloy treated by solid solution-aging and solution-deformation-compression (ECAP) -period was tested by tensile testing machine, X-ray diffraction (XRD) and crystal orientation analysis (EBSD ) Tensile properties of 7085 aluminum alloy, the internal dislocation density, cell boundaries (small angle grain boundaries) and grain boundaries (large angle grain boundaries) were studied, combined with the yield strength measured by tensile test, quantitative calculation of strengthening Item Contribution to the reinforcement of aluminum alloys in different states. The results show that the tensile strength of 7085 aluminum alloy processed by solution-deformation-aging process increases from 381.2 MPa to 475.6 and 543.3 MPa, respectively, compared with the conventional solution-aging process. The dislocation strengthening increases significantly from zero To 107.4 and 180.6 MPa, respectively. The small angle strengthening increased significantly from 10.4 MPa to 89.1 and 116.4 MPa, respectively. The strength of 7085 aluminum alloy comes from the dislocations and the small-angle grain boundaries in the material. The large deformation after solution treatment accelerates the aging and reduces the aging precipitation hardening. It is also found that the strengthening effect of the intense plastic deformation process (ECAP) is higher than that of the conventional plastic deformation process (compression deformation).