(1. 山東大學(xué) 液固結(jié)構(gòu)演變與加工教育部重點(diǎn)實(shí)驗(yàn)室，濟(jì)南 250061； 2. 山東鋼鐵股份有限公司 萊蕪分公司，萊蕪 271100)
摘 要: 采用室溫機(jī)械球磨、熱等靜壓和熱擠壓工藝制備超細(xì)晶5083鋁合金，利用X射線衍射(XRD)、透射電鏡(TEM)對材料的顯微組織進(jìn)行分析和觀察，并對所制備材料的化學(xué)成分、密度、硬度和拉伸性能進(jìn)行測定，在理論分析的基礎(chǔ)上，半定量估算各種強(qiáng)化機(jī)制對材料強(qiáng)度的貢獻(xiàn)。結(jié)果表明：制備的超細(xì)晶5083鋁合金的平均晶粒尺寸為322 nm，相對密度為99.72%，屈服強(qiáng)度和抗拉強(qiáng)度分別為560 MPa和566 MPa，斷后伸長率為6.3%；斷裂方式為微孔聚集型斷裂；強(qiáng)化機(jī)制包括細(xì)晶強(qiáng)化、彌散強(qiáng)化、固溶強(qiáng)化、位錯(cuò)強(qiáng)化，其中以細(xì)晶強(qiáng)化和彌散強(qiáng)化的貢獻(xiàn)最大。
關(guān)鍵字: 超細(xì)晶；5083鋁合金；機(jī)械球磨；顯微組織；力學(xué)性能；強(qiáng)化機(jī)理
（1. Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, China; 2. Laiwu Branch of Shandong Iron and Steel, Shandong Iron and Steel Co., Ltd., Laiwu 271100, China）
Abstract:The microstructure and mechanical behavior of ultra-fine grained (UFG) 5083 aluminum alloy fabricated by mechanical milling and hot isostatic pressed (HIP) followed by hot extrusion. The chemical composition, density, hardness and tensile property of the UFG 5083Al alloy were also characterized. The results show that the samples show an average grain size of 322 nm. The yield stress, ultimate tensile stress and tensile strain-to-failure are 560 MPa, 566MPa and 6.3%, respectively. The fractographic observations of the as-extruded 5083 alloy demonstrate a feature of microvoid accumulation fracture. Semi-quantitative analysis suggest that the strengthening mechanisms including grain boundaries strengthening, dispersion strengthening, solid-solution strengthening and dislocation strengthening are the dominant strengthening mechanisms. A calculation shows that the grain boundaries strengthening and dispersion strengthening are the dominant strengthening mechanisms.
Key words: ultra-fine grained materials; 5083 Al alloy; mechanical milling; microstructure; mechanical property; strengthening mechanism
