(江蘇大學(xué)先進制造與現(xiàn)代裝備技術(shù)工程研究院，鎮(zhèn)江 212013)
摘 要: 采用硬度與電導(dǎo)率測試、拉伸試驗、晶間腐蝕和剝落腐蝕試驗以及X射線衍射(XRD)、掃描電鏡(SEM)、電子背散射衍射(EBSD)分析等方法研究預(yù)變形對Al-12.45Zn-3.56Mg-1.12Cu-0.21Zr-0.0553Sr鋁合金擠壓材組織與性能的影響。結(jié)果表明：該合金在(121 ℃, 24 h)時效制度下，預(yù)變形處理能有效引入位錯，位錯密度從0.197×10-14 m-2提高到1.156×10-14 m-2；同時，由于位錯對強度的貢獻高達58.7 MPa。根據(jù)EBSD分析，經(jīng)預(yù)變形處理后，合金的低角度晶界所占比例為66.2%，比未經(jīng)預(yù)變形處理的合金提高12.6%，平均晶界角度值降低3.894°，平均晶粒尺寸增長6.396 mm。預(yù)變形能夠明顯提高合金的抗晶間腐蝕性能(最大晶間腐蝕深度由222.1 mm降低至165 mm)，對剝落腐蝕性能的影響不明顯。
關(guān)鍵字: 超高強鋁合金；擠壓材；預(yù)變形；顯微組織；性能
（Institute of Advanced Manufacturing and Modern Equipment Technology Engineering,
Jiangsu University, Zhenjiang 212013, China）
Abstract:The effects of pre-deformation on microstructure and properties of Al-12.45Zn-3.56Mg-1.12Cu-0.21Zr- 0.0553Sr ultra-high strength aluminum alloy extrusion materials were studied by means of micro-hardness tester and electrical conductivity test, tensile test, intergranular and exfoliation corrosion experiment, X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD) analysis. The results show that in the aging system at 121 ℃ for 24 h, the pre-deformation can effectively introduce dislocations,the dislocation density increases from 0.197×10-14 m-2to 1.156×10-14 m-2, and the strength reaches up to 58.7 MPa because of the dislocation contribution.Based on EBSD analysis, after pre-deformation treatment, the low angle grain boundary proportion (66.2%) of the pre-deformation alloy increases by 12.6% than that of the underformed alloy, the mean misorientation value reduces 3.894°, and the average grain size increases by 6.396 μm. The pre-deformation treatment can significantly improve the intergranular corrosion resistance properties (the maximum intergranular corrosion depth reducing from 222.1 μm to 165 μm), but little improvement on exfoliation corrosion performance.
Key words: ultra-high strength aluminum alloy; extrusion materials; pre-deformation; microstructure; property
