摘要
The impacts of asymmetric rolling(ASR)and cold rolling(CR)on the creep-aging behavior of AA2219 alloys were revealed by creep deformation experiments,tensile tests,electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM).The ASR specimens under creep stress condition of 1.2σ0.2(σ0.2 is the yield strength)displayed a 50%higher creep strain than the CR specimens.At a creep stress of 0.5σ0.2,the ASR specimens demonstrated remarkably mechanical properties,with a tensile strength of 525 MPa,a yield strength of 338 MPa,and an elongation of 15.2%.This enhancement can be ascribed to the effective grain refinement and promotion of recrystallization after ASR.Notably,ASR resulted in the formation of higher cube textures and a denser forest dislocation structure compared with CR.Additionally,ASR specimens demonstrated a higher density of dispersive,smallerθ′precipitates and larger average Taylor factors compared with CR specimens.
通过蠕变变形实验、拉伸试验、电子背散射衍射(EBSD)和透射电子显微镜(TEM)探讨了非对称轧制(ASR)和冷轧(CR)对AA2219合金蠕变时效行为的影响。实验结果显示,在蠕变应力为1.2σ_(0.2)(σ_(0.2)为屈服强度)的条件下,ASR试样的蠕变应变比CR试样的高50%。当蠕变应力为0.5σ_(0.2)时,ASR试样表现出更优的力学性能,其抗拉强度达到525 MPa,屈服强度达到338 MPa,伸长率达到15.2%。上述实验结果是因为ASR工艺有效地细化了晶粒尺寸并促进了晶粒的再结晶。相较于CR工艺,ASR工艺能使AA2219合金形成更高立方体织构和位错密度的组织。此外,与CR试样相比,ASR试样的θ′析出相呈更加弥散、细小分布,同时具有较大的平均泰勒系数。
基金
financial supports from the National Key Research and Development Program of China(No.2021YFB3400900)
the National Natural Science Foundation of China(Nos.U22A20190,U2341273,52205435)
the Natural Science Foundation of Hunan Province,China(No.2022JJ40621)
the Science and Technology Innovation Program of Hunan Province,China(No.2020RC4001)
the Project of State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,China(No.ZZYJKT2022-07)。
