Microstructure and tensile properties of magnesium alloy modified by Si/Ca based refiner

Microstructure and mechanical properties of pure magnesium and AZ31 alloy with Ca/Si based refiner addition were investigated. The results indicate that addition of Ca/Si based refiners to pure magnesium and AZ31 alloy results in remarkable microstructure refinement. With proper amount of refiner addition, the grain size in as cast ingots can be one order of magnitude lower than that without refiner addition. Small amount of refiner addition to AZ31 alloy increases both ultimate strength and yield strength significantly,while the ductility of the alloy with refiner addition is similar to that without refiner addition. Addition of refiner improves the deformability of AZ31 alloy and extruded or hot rolled specimens （rods or sheets） with refiner addition exhibit higher surface quality and mechanical properties than those without refiner addition.     

Mullite/Al-Cu-Si复合材料界面微结构研究

用挤压铸造方法制备Mullite/Al-Cu-Si复合材料。用分析透射电镜（ATEM）观察了复合材料的微结构及微成分。结果表明：莫来石（Mullite）纤维由大小不、位相不同、分布不均的细小晶粒组成：在淬火态“纤维／基体”界面和“Si晶体／基体”界面附近基件一侧中．都可发现高密度位错的存在；在Si含量较高的情况下，Mullite／Al-Cu-Si复合材料界面处没有发现界面产物的存在，而在纤维／基体界面处析出非平衡共晶θ（Al，Cu）相。     

Al2O3（p）／Al—Mg复合材料界面微结构研究

利用分析透射电镜研究了液态搅拌法制备的Ａｌ２Ｏ３（ｐ）／Ａｌ－Ｍｇ复合材料界面微结构。结果表明，界面反应产物与基体Ｍｇ含量有关，反应产物与Ａｌ２Ｏ３（ｐ）之间存在一定取向关系，界面附近基体中存在大量位错。     

Effect of pressure on microstructures and mechanical properties of A1-Cu-based alloy prepared by squeeze casting

A new high-strength aluminum alloy with better fluidity than that of ZL205A was developed. The effect of applied pressure during squeeze casting on microstructures and properties of the alloy was studied. The results show that the fluidity of the alloy is 16% and 21% higher than that of ZL205A at the pouring temperature of 993 K and 1 013 K, respectively. Compared with permanent-mold casting, mechanical properties of the alloy prepared by squeeze casting are much higher. The tensile strength and elongation of the alloy are 520 MPa and 7.9% in squeeze casting under an applied pressure of 75 MPa, followed by solution treatment at 763 K for 1 h and at 773 K for 8 h, quenching in water at normal temperature and aging at 463 K for 5 h. The improvement of mechanical properties is attributed to the remarkable decreasing of the secondary dendrite arm spacing（SDAS） and eliminating of micro-porosity in the alloy caused by applied pressure.     

SPS法制备四元合金ZnxBi0.5Sb1.5-xTe3（x=0．05-0．4）的微观结构与电学性能

采用放电等离子火花烧结法(SPS)制备四元ZnxBi0.5Sb1.5-xTe3(x=0.05～0.4)(摩尔分数,下同)合金,得出当Zn的量为0.05时,材料的电导率出现最大值,室温附近其值为2.5×104Ω-1·m-1,大约是三元Bi0.5Sb1.5Te3合金的1.35倍.在同温度下,功率因子p值也取得最大值(1.65×10-3W·m-1·K-2),而三元Bi0.5Sb1.5Te3合金的功率因子p值为1.35×10-3W·m-1·K-2.在该合金中用Zn替代Sb元素后,合金的微结构逐渐随Zn的含量发生变化.     

基于无网格局部Petrov-Galekin法的板结构拓扑优化

为将无网格法的优势集成到结构拓扑优化中,基于无网格局部Petrov-Galerkin(Meshless Local Petrov-Galerkin,MLPG)法进行板结构的拓扑优化.基于带惩罚的各向同性固体微结构(Solid Isotropic Microstructure with Penalization,SIMP...     

蚕丝光学器件的研究进展

蚕丝具有优异的光学特性,在光学器件领域具有广阔的应用前景。介绍了蚕丝光波导、蚕丝光学传感器和蚕丝光学微结构3种蚕丝光学器件的研究进展。其中蚕丝光波导和蚕丝微结构重点介绍了制备方法和性能研究进展,蚕丝光学传感器重点介绍了其在生物医学、环境监测和工业检测等传感领域的应用进展。3种蚕丝光学器件的研究都展示了该方向的理论研究价值和实际应用价值。未来的研究应该继续深入研究蚕丝的光学性能,以及蚕丝光学器件的制备方法和性能优化,实现蚕丝在光学器件领域的更广泛的应用。     

液相烧结碳化硅陶瓷的原位研究（英文）

采用原位分析设备与传统方法相结合的方式研究了以Al2O3和Y2O3为烧结助剂的Si C陶瓷的液相烧结过程。通过高温实时观测炉对样品在测试过程中的收缩曲线以及形貌变化进行了表征,以及对液相形成过程的模拟进行了观测。采用传统分析方法研究了样品的相对密度、抗弯强度、物相组成以及微结构演变从1640℃到1920℃以40℃为间隔的变化情况。研究发现,液相明显开始起作用的温度在1640℃到1680℃之间。经典的液相烧结三阶段理论可以通过微结构以及相对密度等的分析来得到验证。该烧结体系的最佳烧结温度确认为1880℃,最高密度为(99.46±0.37)%,最大强度为(650±26)MPa。     

透绝缘层内窥透视集成电路法中Lock-in的应用

提出一种新的在扫描电子显微镜中非接触无损透过半导体和集成电路表面绝缘层显微内窥透视检测掩盖在其绝缘层下面的半导体的缺陷和集成电路微结构的检测法(简称透表法)和用此法所观测到的图像。同时,本文还介绍了在此新检测法中Lock-in的应用。     

LIGA技术及其在制造可动微结构件中的应用

介绍了将LIGA技术及其与牺牲层技术相结合 ,制造可动微结构的工艺方法。并给出了可实现摆动、转动的可动微结构———微执行器、微传感器和三维加速度传感器的制造过程等应用实例