利用电解沉积技术制备出高纯度、高致密度的块状纳米 Cu 样品。该样品经室温下冷轧,延伸率可高达5100％,且冷轧过程中无加工硬化效应产生。微观结构分析表明纳米晶体 Cu 的变形机制是由晶界运动来控制而非普通粗晶体材料的位错运动机制...利用电解沉积技术制备出高纯度、高致密度的块状纳米 Cu 样品。该样品经室温下冷轧,延伸率可高达5100％,且冷轧过程中无加工硬化效应产生。微观结构分析表明纳米晶体 Cu 的变形机制是由晶界运动来控制而非普通粗晶体材料的位错运动机制。这一发现有力地证明了纳米晶体材料具有与普通多晶材料完全不同的力学行为,并为深入理解纳米材料的结构性能关系及拓展纳米材料的工业应用开辟了新路。展开更多
The superplasticity of Al-6Mg-0.4Mn-0.25Sc-0.12Zr and Al-6Mg-0.4Mn-0.25Er-0.12Zr(mass fraction,%)alloys sheet was investigated,and the effect of Sc and Er was discussed.The results show that the superplastic ductiliti...The superplasticity of Al-6Mg-0.4Mn-0.25Sc-0.12Zr and Al-6Mg-0.4Mn-0.25Er-0.12Zr(mass fraction,%)alloys sheet was investigated,and the effect of Sc and Er was discussed.The results show that the superplastic ductilities of Al-Mg-Mn-Sc-Zr alloy was higher than that of Al-Mg-Mn-Er-Zr alloy at a wide temperature range of 400-540°C and high strain rate range of1.67×10-4-1.67×10-1 s-1.A maximum elongation 673%is obtained at 520°C and 1.67×10-3 s-1 in the Sc-containing alloy;while the Er-containing alloy only gets a maximum elongation 253%at 520°C and 1.67×10-3 s-1.Moreover,the average stress exponent of Sc-containing alloy is about 2.84,which is smaller than that of Er-containing alloy(3.64).Besides,the activation energies of the Sc-containing and Er-containing alloy are 84.8 k J/mol and 87.2 k J/mol,respectively.It is indicated that grain boundary sliding is the dominant mechanism during tensile deformation.According to microstructure examination,the better superplasticity of Sc-containing alloy may be attributed to the presence of Al3_(Sc,Zr)dispersoids,which can inhibit recrystallization and grain growth effectively.展开更多
文摘利用电解沉积技术制备出高纯度、高致密度的块状纳米 Cu 样品。该样品经室温下冷轧,延伸率可高达5100％,且冷轧过程中无加工硬化效应产生。微观结构分析表明纳米晶体 Cu 的变形机制是由晶界运动来控制而非普通粗晶体材料的位错运动机制。这一发现有力地证明了纳米晶体材料具有与普通多晶材料完全不同的力学行为,并为深入理解纳米材料的结构性能关系及拓展纳米材料的工业应用开辟了新路。
基金Project(2014M552149) supported by the China Postdoctoral Science FoundationProject(CX2016B041) supported by the Hunan Provincial Innovation Foundation For Postgraduate,ChinaProject(CSUZC201614) supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘The superplasticity of Al-6Mg-0.4Mn-0.25Sc-0.12Zr and Al-6Mg-0.4Mn-0.25Er-0.12Zr(mass fraction,%)alloys sheet was investigated,and the effect of Sc and Er was discussed.The results show that the superplastic ductilities of Al-Mg-Mn-Sc-Zr alloy was higher than that of Al-Mg-Mn-Er-Zr alloy at a wide temperature range of 400-540°C and high strain rate range of1.67×10-4-1.67×10-1 s-1.A maximum elongation 673%is obtained at 520°C and 1.67×10-3 s-1 in the Sc-containing alloy;while the Er-containing alloy only gets a maximum elongation 253%at 520°C and 1.67×10-3 s-1.Moreover,the average stress exponent of Sc-containing alloy is about 2.84,which is smaller than that of Er-containing alloy(3.64).Besides,the activation energies of the Sc-containing and Er-containing alloy are 84.8 k J/mol and 87.2 k J/mol,respectively.It is indicated that grain boundary sliding is the dominant mechanism during tensile deformation.According to microstructure examination,the better superplasticity of Sc-containing alloy may be attributed to the presence of Al3_(Sc,Zr)dispersoids,which can inhibit recrystallization and grain growth effectively.
