NC306型低压甲醇合成催化剂性能特点与工业应用

ＮＣ３０６外形合适,机械强度高,还原收缩率低,具有较高的活性,且热稳定性好。工厂使用表明,同等工况条件下,粗醇平均时空产率提高１０％～３０％。     

基于MATLABGUI的加工误差的统计分析系统

从加工误差常用的两种基本的统计分析方法（即分布图分析和-x-R图分析）入手.运用运用MATLAB中的GUI工具箱开发了计算机辅助加工误差的统计分析系统,并通过实例,说明了系统数据可视化,数据分析处理智能化、简单化、高效化等优点.     

面向多工序制造过程的e-质量控制体系结构研究

针对复杂产品的加工过程质量控制问题,提出了一种面向多工序制造过程的e-质量控制模式,给出了其功能体系结构.该模式以构建面向加工设备的工序质量e-化模型为基础,综合运用了统计过程控制、设备状态诊断、状态空间建模和数模比对等理论和技术,实现的方法是建立e-质量控制系统.详细分析了制造过程中关键控制参数的选取、传感网络的构建、面向设备前端工序质量e-化模型的建立、基于零件加工特征的多工序过程质量控制模式的集成等关键使能技术,并给出了基于浏览器/服务器结构的e-质量控制系统的实现模式,为实现复杂零件的高精度、数字化加工提供了一条新途径.     

铝合金薄壁件高速加工的切削力和工艺研究

本文对铝合金薄壁体零件切削加工中变形和振动问题进行了分析,建立铣削加工受力模型,结合具体的实验,得到了薄壁件加工变形的基本规律,并据此提出了相应的工艺措施．结果表明：高转速、快走刀以及分步环切法可以有效的减小径向切削力．     

基于SOV的机械产品装配过程质量因素耦合模型

为提高机械产品的装配精度,从而最终提高装配质量稳定性,提出了一种基于SOV理论的机械装配过程质量因素耦合模型.利用灰色关联分析法,识别机械装配过程中影响产品质量的因素,在此基础上,利用状态空间方程构建机械装配系统的误差传递模型,以实现质量影响因素耦合关系的定量分析,提高机械装配过程质量控制与优化策略的时效性.最后以HFUTIE-MES为应用实例,验证了上述方法的可行性和实用性.     

The Causes and Prevention of Smut on Etched AISI 300 Stainless Steels

During the fabrication of stainless steel parts by photochemical machining (PCM), a seemingly random occurrence of a partially-adherent, brown/black deposit, known as smut, can occur. This quality problem has plagued the PCM industry for over 30 years. In the past, the problem has been attributed to “poor etch-quality” stainless steel. However, an extensive investigation by the authors, comprising some 7 person-years of effort, has established that while the metallurgy of the stainless steel has some influence on the formation of smut, by far the most important factor is the condition of the ferric chloride etchant used for etching the parts. The influences of etchant concentration, free hydrochloric acid content, temperature, atmosphere and hydrodynamic flow have now been assessed quantitatively for the first time. The investigation has led to the development of a theory outlining the causes of smut formation, thus providing solutions for its prevention.     

华中HNC-21MD数控系统的应用

本文介绍了华中HNC-21MD数控系统在XK713数控铣床上的应用,给出了电气系统配置及电气控制方案。     

Surface treatment of cutting tool substrates

Today's research activities are concentrated on improving the properties of cutting tools by optimizing manufacturing technologies, by alloying of special cutting materials and by coating of tools. As a result of the poor machinability of new cutting materials, grinding processes get more difficult. Especially in grinding of new WC-carbide and cermet compositions, high mechanical and thermal loads influence the surface topography and surface integrity of the tool. In particular, the coating adhesion depends on the surface structure of the substrate. Variations of subsurface properties cause distinct differences to interface strength and tool life.Influences of surface properties on film adhesion of PVD-coated carbides were investigated. Considered topics are the influence of grinding, micro blasting and water peening of carbides on surface topography and surface integrity as well as effects on film adhesion of (Ti,AI)N-coatings. Residual stress measurements and SEM-pictures were used for characterization of surface properties. Film adhesion was analysed by scratch and indentation tests. Due to increasing interface strength of micro blasted tools a superior wear behaviour in dry machining was observed.     

A 2D finite element analysis of the effect of numerical parameters on the reliability of Ti6Al4V machining modeling

Abstract

The numerical analysis, based on the finite element modeling (FEM), presents nowadays an efficient computational tool. It allows a better understanding of several thermo-mechanical phenomena involved during the machining process. However, its reliability heavily depends on the accurate definition of the numerical model. In this regard, a FE analysis focused on the 2D modeling of the Ti6Al4V dry orthogonal machining was carried out in this study. The relevance of different numerical meshing approaches and finite elements topologies was studied. The effect of the friction coefficient on the numerical chip morphology, its geometry, the cutting and the feed forces was investigated. The adequacy of several compared adaptive meshing approaches, in terms of the modeling of severe contact conditions taking place around the cutting-edge radius, was underlined in the current study. However, numerical serrated chips, closer to the experimental ones, were only predicted when the pure Lagrangian formulation was adopted and a proper determination of the failure energy was carried out. The definition of different mesh topologies highlighted the efficiency of the 4-node quadrangular mesh, with a suitable edge length, in increasing the agreement with the experimental data, while reducing the computing times.     

铍材料精密电火花加工工艺研究

针对铍材料机械加工性能较差的缺点,进行了电火花精密加工工艺的探索;通过负极性和以较低放电能量的加工方式,突破了机械加工极限,得到了厚度为0.05mm左右的铍薄膜。