【摘要】：以固溶-時(shí)效和熱機(jī)械處理(TMT)(固溶-過時(shí)效-熱壓縮)-固溶-時(shí)效加工的超高強(qiáng)鋁合金Al-10.78Zn-2.78Mg-2.59Cu-0.22Zr-0.047Sr為實(shí)驗(yàn)對(duì)象,分別采用電子背散射衍射(EBSD)、X射線衍射(XRD)、硬度測(cè)試和拉伸試驗(yàn)研究合金組織晶粒晶界特征分布、內(nèi)部的位錯(cuò)密度和力學(xué)性能,并定量計(jì)算位錯(cuò)強(qiáng)化和晶界強(qiáng)化值。結(jié)果表明:熱機(jī)械處理對(duì)合金晶粒細(xì)化影響不顯著,平均晶粒尺寸從7.30μm減小至6.04μm,晶界角度從21.45?下降到21.04?,小角度晶界比例從0.588下降到0.546;TMT使峰時(shí)效硬度從2146 MPa(120℃/48 h)提高到2268 MPa(100℃/48h),但對(duì)強(qiáng)度影響較小,二者屈服強(qiáng)度均為600 MPa左右,拉伸斷口均為沿晶和撕裂混合斷裂。合金分別經(jīng)固溶及TMT-固溶后,晶界位錯(cuò)密度均為零,TMT使位錯(cuò)強(qiáng)化與晶界強(qiáng)化的總強(qiáng)化從58.8 MPa下降到57.4 MPa。
[Abstract]:The ultra-high strength aluminum alloy Al-10.78Zn-2.78Mg-2.59Cu-0.22Zr-0.047Sr processed by solution-aging and thermo-mechanical treatment of (TMT) (solid solution-over-aging-hot compression)-solid solution-aging was used as the experimental object. Electron backscattering diffraction (EBSD),) X-ray diffraction (XRD),) hardness test and tensile test were used to study the grain boundary characteristic distribution, dislocation density and mechanical properties of the alloy grains, and the dislocation strengthening and grain boundary strengthening values were calculated quantitatively. The results show that the effect of thermal mechanical treatment on grain refinement is not significant. The average grain size decreases from 7.30 渭 m to 6.04 渭 m and grain boundary angle from 21.45? The grain boundary ratio of small angle decreased from 0.588 to 0.546; TMT increases the peak aging hardness from 2146 MPa (120 鈩，

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