通过热压缩实验研究了锻态等轴组织的TCll钛合金在1030～1090℃和应变速率0．001～0．1s^-1范围内的流变行为和组织演变。分析了该合金在实验参数范围内变形的应力一应变曲线特征。热变形过程动力学分析获得了应力指数和激活能分别为4...通过热压缩实验研究了锻态等轴组织的TCll钛合金在1030～1090℃和应变速率0．001～0．1s^-1范围内的流变行为和组织演变。分析了该合金在实验参数范围内变形的应力一应变曲线特征。热变形过程动力学分析获得了应力指数和激活能分别为4．05，172．3kJ·mol^-1，表明该组织的合金在口区热变形主要是位错的滑移和攀移过程。组织观察和电子背散射衍射（Electron Back Scattered Diffraction，EBSD）测试表明，热变形过程中组织演变以不连续动态再结晶过程进行。该过程中，稳态变形再结晶晶粒尺寸是变形温度和应变速率的函数，而稳态变形组织处于部分动态再结晶状态。通过分析该合金特殊的动态再结晶动力学过程，建立了由原始晶粒尺寸修正的Avrami动态再结晶动力学方程。经验证，与实验数据吻合较好。展开更多
A series of Co-Ni-Fe hydrotalcite like compounds have been synthesized by combining a mixed solution of Co(NO3)2·6H2O,Ni(NO3)2·6(H2O) and Fe(NO3)3·9H2O with a second solution containing NaOH and Na2CO3....A series of Co-Ni-Fe hydrotalcite like compounds have been synthesized by combining a mixed solution of Co(NO3)2·6H2O,Ni(NO3)2·6(H2O) and Fe(NO3)3·9H2O with a second solution containing NaOH and Na2CO3.The compounds have been characterized by XRD,IR and TG-DTA.The results showed that the hydrotalcites with M2+/M3+ molar ratios of 2 to 4 have the nice crystal form and high purity.After calcined,hydrotalcites are converted into composite oxides.It is found that the composite oxides has activity and selectivity for catalyzing the dehydrogenation and dehydration of ethanol.展开更多
文摘通过热压缩实验研究了锻态等轴组织的TCll钛合金在1030～1090℃和应变速率0．001～0．1s^-1范围内的流变行为和组织演变。分析了该合金在实验参数范围内变形的应力一应变曲线特征。热变形过程动力学分析获得了应力指数和激活能分别为4．05，172．3kJ·mol^-1，表明该组织的合金在口区热变形主要是位错的滑移和攀移过程。组织观察和电子背散射衍射（Electron Back Scattered Diffraction，EBSD）测试表明，热变形过程中组织演变以不连续动态再结晶过程进行。该过程中，稳态变形再结晶晶粒尺寸是变形温度和应变速率的函数，而稳态变形组织处于部分动态再结晶状态。通过分析该合金特殊的动态再结晶动力学过程，建立了由原始晶粒尺寸修正的Avrami动态再结晶动力学方程。经验证，与实验数据吻合较好。
文摘A series of Co-Ni-Fe hydrotalcite like compounds have been synthesized by combining a mixed solution of Co(NO3)2·6H2O,Ni(NO3)2·6(H2O) and Fe(NO3)3·9H2O with a second solution containing NaOH and Na2CO3.The compounds have been characterized by XRD,IR and TG-DTA.The results showed that the hydrotalcites with M2+/M3+ molar ratios of 2 to 4 have the nice crystal form and high purity.After calcined,hydrotalcites are converted into composite oxides.It is found that the composite oxides has activity and selectivity for catalyzing the dehydrogenation and dehydration of ethanol.
