Effect of Al on microstructure and mechanical properties of as-extruded Mg–1Mn alloy sheet

The effect of Al addition on microstructure and mechanical properties of hot extruded Mg–1 Mn alloy sheet was investigated. The results revealed that the dynamic recrystallization was promoted by increasing Al content. The ultimate tensile strength and yield strength of the alloy increased with the increase of Al content. The Mg–9 Al–1 Mn alloy exhibited the highest strength, with tensile strength of 308 MPa, 307 MPa, 319 MPa, yield strength of 199 MPa, 207 MPa, 220 MPa and the elongation of 20.9%, 20.1%, 19.2% in 0°, 45°, 90°, respectively.The high strength was mainly attributed to the formation of fine dynamically recrystallized grains and large amounts of the second phase. The strengthening mechanism of the alloys was explained.     

Microstructure,mechanical properties and wear resistance of an Al–Mg–Si alloy produced by equal channel angular pressing

Microstructure, mechanical properties and wear resistance in an ultrafine-grained Al–Mg–Si alloy fabricated utilizing a combination of equal channel angular pressing (ECAP) and dynamic aging were investigated in this paper. The results indicated that the grain size of the ECAP alloy was significantly refined, i.e., to ~239 nm after three ECAP passes. Meanwhile, the yield and tensile strength of the ECAPed material reached 340 MPa and 445 MPa, respectively, while maintaining a significant uniform elongation of 14%. Wear resistance results demonstrated that the wear rate, wear depth and width of the ECAPed material decreased in comparison with the solution-treated (SST) and peak-aged (T6) conditions under a load range of 5–25 N. The adhesive wear that occurs in the undeformed specimens at 10 N does not appear in the ECAPed specimen at the same load, indicating that the ECAPed specimen delay the appearance of more serious wear mechanisms under certain loads. The cooperative interaction of high density nano-scale β" precipitates and dislocations resulted in a combination of super-high strength and good work hardening ability which suppressed the extension of cracks between the friction layer and the plastic deformation zone. As a consequence, the combination of ECAP and dynamic aging brings a significant improvement for antifriction performance of the 6061 aluminum alloy.     

镁改型蛭石对铵离子的交换性能

对经人工改型所得的镁型蛭石进行了铵离子交换性能的研究．在不同pH值下测定了镁型蛭石对NHr的全交换容量，在不同温度下测定了样品的平衡等温线．结果表明，镁型蛭石对NH4^ 的交换总量随pH值的变化而波动，在pH值为7时其交换总量为59．32mmol／100g，其选择性随温度的降低而升高，这为蛭石作为一种新型填料提供了一定的理论依据。     

超塑性板材气压成形模具的设计与计算

介绍了金属的“超塑性”概念及其特点,阐述了超塑性材料Zn-22%Al板材气压成形的原理,着重解释了其板材气压成形模具的设计与计算,对生产实际与理论探讨具有现实意义。     

实验性脾虚证大鼠血清中微量元素含量的研究

用破气苦降药加饮食失节法复制了大鼠脾虚证模型。采用原子吸收光谱法检测了血清发Ｚｎ、Ｃｕ和Ｆｅ的含量。本研究证明，脾虚证大鼠血清Ｚｎ值明显降低（Ｐ＜０．００１）；Ｃｕ值、Ｆｅ值无明显差异（Ｐ＞００５）；Ｃｕ／Ｚｎ比值上升。用中药加味四君子汤治疗后，血清Ｚｎ值明显回升并高于正常水平（Ｐ＜００５），Ｃｕ值回升（Ｐ＜０．０５），但Ｆｅ值和Ｃｕ／Ｚｎ比值与自然恢复及对照组比较无显著性差异。这说明：１．脾虚组Ｚｎ的降低可能与消化吸收障碍有关；２．加味四君子汤对脾虚证时血清Ｚｎ及Ｃｕ／Ｚｎ比值的变化有明显的调整和恢复作用．     

Improvement in hydrogen storage performance of Mg by mechanical grinding with molten salt etching Ti3C2Clx

Mg-based materials are currently a hot research topic as hydrogen storage materials due to their considerable theoretical hydrogen storage capacity. However, the kinetic performance of hydrogen absorption and desorption of Mg is too slow and requires high temperature, which seriously hinders the application of this material. MXene is a new type of two-dimensional material with significant role in improving thermodynamics and kinetics. In this experiment, a two-dimensional layered MXene containing Cl functional group was prepared by molten salt etching using the Ti-containing MAX phase as the raw material. Then different ratios of Ti₃C₂Cl_x were uniformly dispersed onto the surface of Mg by high energy ball milling. The samples were characterized by hydrogen absorption and desorption kinetics, SEM, XRD, XPS, and DSC to investigate the effect of Ti₃C₂Cl_x on the hydrogen absorption and desorption performance of Mg. The onset hydrogen absorption temperature can be reduced to room temperature and the hydrogen release temperature is reduced by 200 ​°C by doping Ti₃C₂Cl_x. And there is also 5.4 ​wt% hydrogen storage in the isothermal hydrogen absorption test at 400 ​°C. The results of DSC demonstrate that the E_a of Mg+15 ​wt% Ti₃C₂Cl_x was reduced by 12.6% compared to pristine Mg. The ΔH is almost invariable. The results of XPS show that the presence of multivalent Ti promotes electron transfer and thus improves the conversion between Mg²⁺/Mg and H⁻/H. This study provides a guideline for further improving the hydrogen absorption and desorption performance of Mg-based hydrogen storage materials.     

苯甲醛缩氨基硫脲Cu(I)、Zn(Ⅱ)配合物的直接电化学合成

用电化学金属阳极氧化法在非水溶剂中合成了苯甲醛缩氨基硫脲（ＨＬ）与Ｃｕ（Ｉ）、Ｚｎ（Ⅱ）配合物,通过元素分析、红外光谱、紫外光谱、磁矩、摩尔电导等对配合物进行了表征。     

CO对Cu—Zn—Zr催化剂CO2加氢合成甲醇的影响

用四种ＣＯ含量不同的原料气对Ｃｕ－Ｚｎ－Ｚｒ催化剂进行ＣＯ２加氢合成甲醇的研究．结果表明ＣＯ能抑制催化剂表面产生逆水汽变换反应活性位的ＣＯ２吸附,从而有效地提高ＣＯ２加氢合成甲醇的选择性     

镁修饰丝光沸石对萘异丙基化选择性的影响

2，6-二异丙基萘是制备高级聚酯材料PEN和液晶聚合物的原料。用择形催化剂丝光沸石代替传统的Friedel—Crafts催化剂，在高压釜中以萘和丙烯为原料经异丙基化反应合成了2，6-DIPN。采用浸渍法用少量镁盐修饰水汽脱铝氢型丝光沸石（SDHM），减少了SDHM外表面的强B酸中心和非择形产物的生成，从而使2，6-DIPN的择形率提高到71％。2，6-DIPN／2，7-DIPN摩尔比达到2．89，有利于2，6-DIPN的分离提纯。     

水滑石与氢氧化镁纳米晶的液相法制备及其生成机制

研究了纳米晶镁铝水滑石Mg6Al2(OH)16CO3·4H2O与 Mg(OH)2 的液相法制备及其物相变化.X射线衍射(XRD)和透射电镜(TEM)分析表明,在制备温度分别为30 ℃的低温和190 ℃的高温,可获得纯度大于99%的氢氧化镁针状纳米晶,在45~150 ℃的中间温度范围,可获得纯度大于 99%的镁铝水滑石针状纳米晶.合成温度由35 ℃提高到45 ℃时,生成物相由氢氧化镁变成镁铝水滑石相;合成温度由 170 ℃提高到190 ℃时,生成物相由镁铝水滑石相变成氢氧化镁相.提出低温时生成物的变化与瞬间生成无定形态的Mg(OH)2 有关,无定形态的Mg(OH)2 沉淀为Al13(OH)7 32 中铝离子以及CO2-3 扩散进入Mg(OH)2提供了更为有利的条件.高温时生成物的变化,是由于温度的升高,使含结晶水的镁铝水滑石纳米晶中间层中的高极性水分子堆积所要求的一定的物理条件受到破坏所致.