颗粒增强金属基复合材料加工技术进展

颗粒增强金属基复合材料具有优良的物理力学性能,但材料的难加工特性限制了其应用。因此,对颗粒增强金属基复合材料加工技术的研究与发展是促进其进一步应用的关键之一。本文从加工方法、加工质量等方面综述了国内外颗粒增强金属基复合材料加工技术的进展情况,并指出了当前存在的问题及解决对策。     

芯片用金刚石增强金属基复合材料研究进展

随着电子设备集成化程度越来越高,对高导热封装材料的需求也越来越大,金刚石增强金属基复合材料凭借其高导热性能成为研究焦点。然而,由于金刚石颗粒与金属基体之间的不润湿特性,具有高导热性的金刚石增强金属基复合材料难以制备。文中综述了金刚石增强金属基复合材料的研究进展,包括界面改性、工艺参数优化和复合材料制备方法,并指出了金刚石增强金属基复合材料目前存在的问题和今后的研究方向。     

金属基复合材料超声切削特性的研究

Al基SiC颗粒强复合材料是一种新型复合材料，在切削颗粒增强复合材料时，切削性能和普通材料有很大差别，通过实验，从超声切削机理以及加工表面质量等方面对超声振动切削金属基复合材料的特性进行研究，为复合材料的高效加工提供理论依据。     

SiC颗粒增强铝基复合材料高速铣削工艺研究

从颗粒增强金属基复合材料的应用和切削加工现状出发 ,针对SiC颗粒增强铝基复合材料的高速切削加工性能进行了试验分析。通过铣削试验 ,研究了铣削速度对铣削力、加工表面粗糙度、表面形貌以及刀具磨损的影响 ,分析了该材料的高速切削机理 ,并获得了能够保证对其进行高效高精度加工的合理工艺参数。     

五边形中空电极电火花加工颗粒增强金属基复合材料试验研究

针对颗粒增强金属基复合材料的加工难题以及采用中空管电极电火花打孔排屑等问题,提出了采用多边形中空管电极电火花法加工该类材料。分别采用截面为圆形和五边形的两种中空管电极,对比研究不同颗粒增强金属基复合材料加工的效率。利用正交试验法研究颗粒增强金属基复合材料中不同加工参数对加工效率的影响,得到了多边形中空电极电火花加工的最佳工艺参数。试验结果表明,截面为五边形的中空电极较圆形中空电极电火花加工效率高,加工时间最大缩短51.8%;正交试验的最佳工艺组合为脉冲宽度32ms,占空比2∶3,峰值电流7A。     

金属基复合材料概述(1)

金属基复合材料是由陶瓷颗粒成纤维（如SiC,Al2O3,TiC,TiB等）增强金属或者合金基体而得到的,具有高的比刚度、比强度、耐磨性和高温性能,且具有可设计性,是一类高性能先进材料,在航空、航天、汽车等领域具有良好的应用前景。东南大学已开发出铝基、镁基、锌基、钛基等多种复合材料,有些已开始应用于汽车发动机。目前,可供应多种金属基复合材料的铸件与型材。     

颗粒增强金属基复合材料的特种加工研究现状

综述了颗粒增强金属基复合材料的特种加工技术的研究进展,指出了存在的问题及其解决对策。     

高精度微细放电钻削金属基复合材料实验研究

为实现颗粒增强铝基复合材料盲孔高精度放电加工,提出了一种利用电回路信号实时检测电极损耗,并进行轴向电极补偿的方法。为验证这种补偿方法的有效性,采用黄铜和紫铜两种不同的电极材料对碳化硅颗粒增强金属基复合材料进行不同深度的微盲孔加工。实验结果表明,采用轴向补偿方法能实现颗粒增强铝基复合材料高精度微盲孔的电火花加工,其盲孔加工的深度偏差下降约22%,扩孔率下降约2%,锥度下降约13%。     

颗粒增强金属基复合材料的制备进展

介绍颗粒增强金属基复合材料的常用制备工艺,分析各种制备方法的优缺点;论述对颗粒增强金属基复合材料制备技术研究的难点,并展望金属基复合材料的发展。     

气中电火花加工颗粒增强金属基复合材料的有限元分析

根据傅里叶热传导理论,建立了气中电火花放电加工颗粒增强金属基复合材料的二维有限元仿真模型。利用有限元软件ANSYS分别采用高斯热源模型和均匀热源模型对单脉冲放电加工金属基复合材料的温度场进行数值模拟。根据温度场的分布情况,对比分析了在两种不同热源模型下放电凹坑的形貌、直径和深度,并与实验结果进行比较,结果表明,与高斯热源模型相比,均匀热源模型能较好地预测单脉冲放电加工金属基复合材料的放电凹坑特征。根据电火花加工金属基复合材料的特点,对均匀热源模型中所采用的放电通道半径进行了修正,结果表明,修正后的模型能够比较准确地模拟单脉冲放电加工金属基复合材料放电凹坑的几何特征。     

颗粒增强镁基复合材料的研究进展

镁基复合材料具有很高的比强度、比刚度以及优良的阻尼减震性能,是汽车制造、航空航天等领域的理想材料之一。综述了颗粒增强镁基复合材料的研究概况,着重介绍了其制备方法、力学以及阻尼性能,并展望了它的发展趋势。     

ROTARY ULTRASONIC MACHINING OF TITANIUM ALLOY: EFFECTS OF MACHINING VARIABLES

Titanium and its alloys are finding prime applications in industries due to their unique properties. However, the high cost of machining is one of the limiting factors for their widespread use. Tremendous efforts are being made to improve the existing machining processes, and new processes are being developed to reduce the machining cost in order to increase the titanium market. However, there is no report on the systematic study of the effects of machining variables on output parameters in rotary ultrasonic machining of titanium and its alloys. This paper presents an experimental study on rotary ultrasonic machining of a titanium alloy. The cutting force, material removal rate, and surface roughness (when using rotary ultrasonic machining) of a titanium alloy have been investigated using different machining variables.     

高速加工发展概况

本文全面介绍了高速加工的基础理论及发展过程 ,并对高速加工的优点和特性、高速加工的安全性、高速主轴及机床部件的发展从整体上进行了深入的讨论。同时 ,作者对发展高速加工需要的关键技术提出了研究方向 ,最后展望了高速加工的应用前景     

耳机模具的高速数控加工

利用Pro/E软件编制耳机注塑模具嵌件的数控加工程序。针对各加工阶段的特点和要求 ,创建了用于粗加工的铣削体积块和用于精加工的铣削曲面 ,通过加工工序的合理设置规划了各阶段的加工方式 ,并制定了模具的高速加工策略     

High speed electrochemical boring

Electrochemical machining (ECM) is widely used nowadays in a great variety of processes, especially in the aero and auto industries. The main machining processes, where high tool feed rates are required, are drilling, cavity sinking, broaching and grinding. In addition, the non-equilibrium machining processes, where stationary electrodes are utilized, have important practical applications in the fields of deburring and embossing. Electrochemical honing is a non-equilibrium process. EC honing is a new technique which, in spite of being used in some industrial plants, is still not fully described, requiring more information about the process. This work presents a comparative study, between rotating and non-rotating electrodes for the enlargement of conventionally pre-drilled holes. The comparison covers the rate of metal removal, dimensional accuracy, surface finish and power consumption. The beneficial advantages of using high rotational speeds on component accuracy are verified. The results emphasize that each process has its own particular characterization, appropriate field of application and tooling system.     

Material bead deposition with 2 + 2 ½ multi-axis machining process planning strategies with virtual verification for extruded geometry

Process planning for hybrid manufacturing, where additive operations can be interlaced with machining operations, is in its infancy. New plastic- and metal-based hybrid manufacturing systems are being developed that integrate both additive manufacturing (AM) and subtractive (machining) operations. This introduces new process planning challenges. The focus of this research is to explore process planning solution approaches when using a hybrid manufacturing approach. Concepts such as localized AM build ups, adding stock to a CAD model or section for subsequent removal, and machining an AM stock model are investigated and illustrated using virtual simulations. A case study using a hybrid laser cladding process is used to demonstrate the opportunities associated with a hybrid solution. However, unlike machining, the process characteristics from system to system vary greatly. These are portrayed via a high power, high material deposition feed rate laser cladding system. There are unique challenges associated with AM processes and hybrid manufacturing. New tools and design rules need to be developed for this manufacturing solution to reach its potential.     

高速切削刀具材料及其应用

高速切削能加工出精度较高的零件,还能降低加工成本。高速切削技术已经成为最有前途的先进制造技术之一,其应用领域正在持续扩展。高速切削技术是随着刀具技术如刀具材料等的发展而发展起来的。介绍了高速切削中所使用的金刚石、立方氮化硼、陶瓷、金属陶瓷和涂层刀具等的性能、适用范围和发展方向,并介绍涂层刀具、超细晶粒硬质合金和高速钢刀具的制备技术,以促进高速切削技术的推广应用。     

Off-line optimization on NC machining based on virtual machining

Virtual machining, based-on the model of a machining system, aims to simulate, evaluate and optimize the actual machining process with high sense of reality. It provides digital off-line optimization tools for NC machining. Taking advantage of virtual machining used in machining process simulation, one can build the framework of optimization system on NC machining so that the processes of reliability verification, cutting parameter optimization and error compensation can be integrated into one system to improve machining processes comprehensively. The optimization is realized via modifying NC programs. Several key issues such as virtual machining, cutting parameters optimization, error prediction and compensation are also highlighted. Optimization systems based on virtual machining have been developed to demonstrate the effectiveness of off-line optimization for different purposes. The results show that the machining process is obviously improved.     

Machining of NiTi-shape memory alloys-A review

The emerging trends in the development of advanced smart materials with better unique properties under different environments for a particular application fascinate the researchers and industrialists. Nickel-Titanium based shape memory alloys are exotic materials due to their unique properties such as SME, SE, high damping characteristics, high corrosion and wear resistance and biocompatibility. This article presents an overview of machining processes that can be used to machine the NiTi and its surface induced characteristics such as microhardness, surface roughness, topography, induced layer, residual stress, fatigue and phase transformation. The surface integrity characteristics are discussed for machining of NiTi-SMAs under the category of traditional, non-traditional and micro-machining with the effect of input parameters such as cutting speed, feed, depth of cut, type of lubricant and type of coating material on cutting tool. The conventional machining of NiTi alloys are quite complicated due to high toughness, severe strain hardening, fatigue hardening and distinctive property of NiTi-SMAs such as pseudoelastic and shape memory effect. From this study, non-traditional process is significantly used to machine the NiTi-SMAs due to its better results on surface integrity characteristics. Consequently, future trends are also identified for machining the NiTi-SMAs and to improve the surface integrity characteristics.