期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
Microstructure and mechanical properties of AZ91 magnesium alloy subject to deep cryogenic treatments 被引量:3
1
作者 Gui-rong Li hong-ming wang +3 位作者 Yun Cai Yu-tao Zhao Jun-jie wang Simon P.A. Gill 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第9期896-901,共6页
AZ91 magnesium alloy was subjected to a deep cryogenic treatment. X-ray diffraction (XRD), scanning electronic microscopy (SEM), and transmission electronic microscopy (TEM) methods were utilized to characterize... AZ91 magnesium alloy was subjected to a deep cryogenic treatment. X-ray diffraction (XRD), scanning electronic microscopy (SEM), and transmission electronic microscopy (TEM) methods were utilized to characterize the composition and microstructure of the treated samples. The results show that after two cryogenic treatments, the quantity of the precipitate hardening β phase increases, and the sizes of the precipitates are refined from 8-10μm to 2-4μm. This is expected to be due to the decreased solubility of aluminum in the matrix at low temperature and the significant plastic deformation owing to internal differences in thermal contraction between phases and grains. The polycrystalline matrix is also noticeably refined, with the sizes of the subsequent nanocrystalline grains in the range of 50-100 nm. High density dislocations are observed to pile up at the grain boundaries, inducing the dynamic recrystallization of the microstructure, leading to the generation of a nanocrystalline grain structure. After two deep cryogenic treatments, the tensile strength and elongation are found to be substantially increased, rising from 243 MPa and 4.4% of as-cast state to 299 MPa and 5.1%. 展开更多
关键词 magnesium alloys cryogenic treatment MICROSTRUCTURE mechanical properties
下载PDF
Secondary Structure Analysis of Native Cellulose by Molecular Dynamics Simulations with Coarse-Grained Model
2
作者 Shuai Wu Hai-yi Zhan +1 位作者 hong-ming wang Yan Ju 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第2期191-198,I0004,共9页
The secondary structure of different Iβ cellulose was analyzed by a molecular dynamics sim- ulation with MARTINI coarse-grained force field, where each chain of the cellulose includes 40 D-glucoses units. Calculation... The secondary structure of different Iβ cellulose was analyzed by a molecular dynamics sim- ulation with MARTINI coarse-grained force field, where each chain of the cellulose includes 40 D-glucoses units. Calculation gives a satisfied description about the secondary structure of the cellulose. As the chain number increasing, the cellulose becomes the form of a helix, with the diameter of screw growing and spiral rising. Interestingly, the celluloses with chain number N of 4, 6, 24 and 36 do show right-hand twisting. On the contrast, the celluloses with N of 8, 12, 16 chains are left-hand twisting. These simulations indicate that the cellulose with chain number larger than 36 will break down to two parts. Besides, the result indicates that 36-chains cellulose model is the most stable among all models. Furthermore, the Lennard-Jones potential determines the secondary structure. In addition, an equation was set up to analyze the twisting structure. 展开更多
关键词 cellulose Coarse-grained model Secondary structure Molecular dynamics
下载PDF
Effect of Boron Mud and CaF_2 on Surface Tension and Density of CaO-SiO_2-B_2O_3 Ternary Slag Systems 被引量:7
3
作者 Li-li YANG hong-ming wang +1 位作者 Xiang ZHU Gui-rong LI 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2014年第8期745-748,共4页
The effect of boron mud and CaF2,which were used as fluxing agents,on surface tension and density of CaO-SiO2-B2O3 ternary slag systems was investigated.The surface tension and density were measured by using the ring ... The effect of boron mud and CaF2,which were used as fluxing agents,on surface tension and density of CaO-SiO2-B2O3 ternary slag systems was investigated.The surface tension and density were measured by using the ring detachment method and Archimedean method,respectively.The results indicated that surface tension and density of the slag systems decreased with increasing temperature in the range of 1380-1480℃.When 5%-10% CaF2 was employed as fluxing agent,the surface tension and density of slag were decreased with increasing CaF2 content,and the surface tension changed from 0.3to 0.6N/m,while the density changed from 3.4to 4.1g/cm3.However,when using 5%-10%boron mud as fluxing agent,the surface tension was enhanced,whereas the density decreased with the increase of boron mud content,and the variation range was 0.4-0.6N/m for surface tension and 3.2-3.9g/cm3 for the density.As a conclusion,using boron mud as fluxing agent to substitute for CaF2 did not cause significant changes in slag surface tension and density. 展开更多
关键词 boron mud calcium fluoride surface tension DENSITY
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部