钛及钛合金抑菌技术的研究进展

钛作为食品接触材料不具备抑菌功能,使用过程中易滋生细菌对人体健康不利。文章主要介绍了钛及钛合金抑菌处理常用方法及最新的研究进展,包括合金化处理,离子注入、热喷涂、微弧氧化等表面处理方式。对抑菌钛合金的研究方向及其在日用餐具、炊具、水具等行业的应用前景作了展望。     

汽车仪表板模型表面的反向工程重构技术

曲面重构技术是反向工程的重要组成部分,在工业制造、医疗、艺术、军事等应用领域意义重大,已成为国内外的研究热点.对于反向工程的研究内容,数据获取方法、曲面重构技术理论和相关软件进行了介绍,并举例重点阐述了一些典型的方法.     

电渣熔铸渣池热电场有限元模拟的前置处理

对电渣熔铸渣池进行了热电场有限元模拟的前置处理,建立了电渣熔铸渣池热电场数学模型,定义了以自耗电极、渣壳、水冷结晶器、渣池为对象的计算区域.借助大型有限元软件ANSYS,对计算区域进行了合理的单元、插值函数选取以及网格划分,研究发现渣池存在两个区域:一是温度很高、电流密度很大且分布很不均匀的小区域,位于自耗电极端部附近,为高热源区,另一是电流密度小且分布几乎均匀的大区域,为低热源区.     

Accuracy test of five-axis CNC machine tool with 3D probe–ball. Part I: design and modeling

The error model of CNC machine tool describes the relationship between the individual error source and its effects on the overall position errors. A practical problem in applying this technique to five-axis machine tool is that the predicted position errors cannot be justified. This paper, the first in a set of two, presents a new measurement device, the probe–ball, which can be used to measure the overall position errors of five-axis machine tools directly. To perform the accuracy test, a three-degree-of-freedom (3D) measuring probe is installed in the main spindle and a base plate is fixed on the turntable. The kinematic chain of the five-axis machine tool is then closed through connecting the central ball on the base plate with the extension bar of the probe. To generate simultaneous axes motion under the condition of closed kinematic chain, the central ball is defined as origin of the workpiece coordinate frame and the probe is driven along a path on a spherical test surface with the central ball as center. The overall position errors are measured with the 3D measuring probe. A theoretical model is derived to explain the nature of the probe–ball error measurements.     

Effects of rapid solidification on the phase structures and electrochemical properties of a V3TiNi0.56Co0.14Nb0.047Ta0.047 alloy

The crystal structures and electrochemical properties of a V₃TiNi_0.56Co_0.14Nb_0.047Ta_0.047 alloy prepared by the melt-spinning method were studied. The rapidly solidified alloy consists of a major Vanadium-based solid solution phase and a secondary Ti₂Ni-based phase. The secondary phase exists between the dendritic arms of the major phase, showing a typical eutectic characteristic. With increasing cooling rate, the amount of the secondary phase decreases but the lattice parameters of both the major phase and the secondary phase show no obvious change. Because the disappearance of the catalytic effect of the secondary phase, the rapidly solidified alloy shows bad electrochemical properties except cycle stability.     

Mg-Sr牺牲阳极显微组织和电化学性能的研究

研究了Mg-Sr牺牲阳极的显微组织和电化学性能的特征.结果表明,Mg-Sr牺牲阳极的晶粒尺寸随Sr含量的增加而减小;当Sr质量分数为0.19%时,电流效率达到58.56%,开路电位达到-1.735 VSCE;Sr的质量分数再增加,Mg-Sr阳极的电流效率降低,开路电位正移.研究认为,Sr的质量分数为0.19%时,晶界析出的Mg17Sr2相（弱阴极相）和α-Mg基体（阳极相）组成电偶对,阻碍了阳极晶间腐蚀,减少了晶粒大块脱落, 且Sr能够和Mg、Fe形成弱阴极性化合物降低Fe的危害,电流效率升高,同时晶粒细化,晶界面积变大,杂质相分布更均匀,开路电位负移;Sr含量大于0.19%时,过量的Mg17Sr2相作为阴极相加大了阳极的自腐蚀,电流效率下降,开路电位正移.     

Zr替代Ti对Ti19．5V40Mn16．2Cr9．8Ni14．5合金的影响Ⅱ：电化学性能

在对合金微观结构和储氢性能研究的基础上，详细考察了少量Zr取代Ti对Ti19．5V40Mn16．2Cr9．8Ni14．5合金电化学性能的影响。通过观察电极的充放电行为，并结合EIS及多种极化曲线的分析结果，发现少量Zr对Ti的取代能够显著提高合金电极的实际电化学容量和循环稳定性，而且还能在一定程度上改善合金的电极动力学性能。对于这些性能的改善，从合金微观结构方面进行了解释。     

机械合金化Al—12Ti—6Nb合金的热稳定性

将机械合金化（ＭＡ）Ａｌ－１２Ｔｉ－６Ｎｂ合金在５５０℃下空气中长时间暴露后，用光学显微镜和电子探针对其组织结构变化进行了观察与分析，测定了维氏硬度。结果表明，ＭＡＡｌ－１２Ｔｉ－６Ｎｂ表现出良好的热稳定性，在５５０℃下暴露２００ｈ后，Ａｌ３Ｔｉ中的亚稳的α－Ｔｉ核才全部转变为Ａｌ３Ｔｉ，Ａｌ３Ｔｉ颗粒随之粗化，饼状的Ａｌ３Ｔｉ变成椭球体；Ａｌ３Ｔｉ颗粒的粗化是通过Ｔｉ，Ａｌ原子扩散所控制的α－Ｔ     

A new method of automatic polishing on curved aluminium alloy surfaces at constant pressure

This paper presents original research results of automatic polishing on curved surfaces of aluminium alloy moulds at constant pressure. The automatic polishing of aluminium alloy material is achieved. A parameter S is defined, which can express the comprehensive influential factors in the automatic polishing process and give a relationship among the polishing quality and the various machining variables. Based on this, a new method for comprehensive control of polishing quality is suggested.     

Mo的替代对FeNbBCu软磁纳米晶合金磁谱的影响

本文研究了Fe82Nb7-xMoxB10Cu1(x=0,1,3,5）系列纲伙晶软磁合金中Mo的含量对磁导率谱（频率范围1kHz-1MHz)的影响，并用畴壁钉扎理论进行了解释，在磁谱中观测到随着Mo含量的增加，弛豫频率线性地上升，μ′随外加磁场幅度变化曲线表明其原因在于Mo的替代导致了钉扎场的增强。