细长轴的加工工艺探讨

细长轴的加工一直是车床的加工难点.本文通过对细长轴工艺特点的分析并结合生产实践以活塞杆为例对细长轴的加工作出了详细的阐述,提出了解决细长轴加工时弯曲变形问题的机械加工工艺措施,并应用于生产取得了良好效果.     

探究不锈钢细长轴的加工工艺

与普通细长轴加工相比,不锈钢细长轴加工难度更大,主要是因为,不锈钢具有不易散热以及切削温度过高等特点,所以整体施工把控难度相对较大。为达到最佳加工效果,加工企业开始对不锈钢细长轴加工展开了全面研究。本文也将以搅拌槽细长轴加工为例,通过对加工难点的分析,对不锈钢细长轴加工工艺展开深度探讨,期望能够为不锈钢细长轴加工提供一些理论依据。     

常见短应力线轧机接轴托架简介

近年来随着棒线材短应力线轧机设备及技术的飞速发展,同时出现了多种形式的接轴托架。本文就几种应用最广泛的接轴托架的结构特点和应用进行作简要的对比分析,并介绍一种新型板式链联接弹簧缓冲柔性闭环系统接轴托架,以便使用者更好的选择。     

PLC在轴加工设备的应用

介绍了PLC在输送设备制造公司轴加工设备中的应用过程、控制系统的组成、特点、功能以及控制软件的设计。通过实际应用表明,该系统能够可靠、准确地完成轴加工操作,实时监控运行状况,生产快速,尺寸控制良好。     

矩形大花键主轴与花键套加工工艺

通过对矩形大花键主轴及内矩形花键套特点的分析,运用样板加工方法解决了矩形大花键轴及内矩形花键套的加工精度难题.     

针对H13芯棒的加工实例探讨细长轴的加工工艺

细长轴的加工一直是车床的加工难点,本文以H13芯棒加工为实例对细长轴的加工做出了详细阐述,提出了解决细长轴加工时弯曲变形问题的机械加工工艺措施,在芯棒加工中取得了良好效果。     

金属增材制造技术的应用与发展

金属增材制造技术是一种具备高加工柔性、快速制造响应能力的先进加工技术。本文重点论述了几种典型的增材制造技术,介绍了各自的原理与特点,探讨了金属增材制造在工业生产的应用,并对今后的发展趋势做出分析。     

带冷机柔性传动箱体的加工

本文通过带冷机柔性传动箱体的结构特点及使用性能的分析，并据设备能力设计了切实可行的工艺方案，先面后孔，立车与镗床相结合完成孔系加工，重点论述了分离式箱体的工艺设计和分析，对同类产品的加工具有深远的指导意义。     

大型八棱锥卷筒研制及关键技术

介绍了大型八棱锥卷筒的工作原理、结构特点及主要性能参数,运用有限元软件进行卷筒静强度分析,优化卷筒设计参数,合理选择材料;研究了卷筒扇形板防变形、棱锥轴精密分度加工及卷筒整体加工工艺优化等制造技术。     

五轴数控加工仿真器的研制

基于离心叶轮五轴数控整体加工的需要,在Auto CAD平台上运用VBA成功开发了五轴数控加工仿真器,该系统能够灵活接收刀位数据和标准数控加工代码两种控制信息,然后迅速动态生成相应的刀具轨迹图形,从而为离心叶轮类零件的五轴数控整体加工的刀具几何参数设计提供了最明了的评价依据.应用结果表明,该五轴数控加工仿真器既具有指导实际生产的重要意义,也为避免刀具干涉提供了强有力手段.     

Active wear and failure mechanisms of TiN-Coated high speed steel and tin-coated cemented carbide tools when machining powder metallurgically made stainless steels

In this study, active wear and failure mechanisms of both TiN-coated high speed steel and TiN-coated cemented carbide tools when machining stainless steels made by powder metallurgy in low and high cutting speed ranges, respectively, have been investigated. Abrasive wear mechanisms, fatigue-induced failure, and adhesive and diffusion wear mechanisms mainly affected the tool life of TiN-coated high speed steel tools at cutting speeds below 35 m/min, between 35 and 45 m/min, and over 45 m/min, respectively. Additionally, fatigue-induced failure was active at cutting speeds over 45 m/min in the low cutting speed range when machining powder metallurgically made duplex stainless steel 2205 and austenitic stainless steel 316L. In the high cutting speed range, from 100 to 250 m/min, fatigue-induced failure together with diffusion wear mechanism, affected the tool life of TiN-coated cemented carbide tools when machining both 316L and 2205 stainless steels. It was noticed that the tool life of TiN-coated high speed steel tools used in the low cutting speed range when machining 2205 steel was longer than that when machining 316L steel, whereas the tool life of TiN-coated cemented carbide tools used in the high cutting speed range when machining 316L steel was longer than that when machining 2205 steel. formerly with the Laboratory of Engineering Materials, Helsinki University of Technology     

大型铝板轧机牌坊加工方法探讨

介绍一种大型铝板轧机牌坊的加工方法,提出如何从工艺路线设计、刀具选择、切削参数设置、切削液应用等方面分析加工方案,确保机架的加工质量。     

硬脆材料加工技术的研究

对硬脆材料的各种用途和加工现状进行了综述,根据硬脆材料抗拉强度低的特点,建立了切削模型。介绍了切削、磨削等主要的几种加工方法的原理、适用范围及最新研究成果,硬脆材料切削和磨削的机理和实验对比,并对特种加工做了简单介绍。     

端铣中工具进给速度的最佳化

This paper deals with the tool feed rate optimization for smoothening of cutting force in end milling of workpiece with corner and straight parts. There is a difference between the cutting force in a corner part cutting and that in a straight part cutting. The cause of this is due to the difference in the instantaneous depths of cut in both cuttings. The scheme of this study is to prevent the generation of excessive cutting force in the corner part machining by comparison with the straight part machining. By dividing the NC (Numerical Control) cutting path of the corner part and changing the tool feed rate in each division, the cutting force in the corner part has been controlled. Furthermore, the possibility of realization of a shortening in machining time has been examined.     

PCBN刀具在切削含硼高速钢轧辊中的应用

分析含硼高速钢轧辊的加工性能,选用PCBN刀具作为切削刀具,通过加工过程的分析得出合理的切削参数。     

铝合金高速加工的研究

简要介绍了高速加工的概念、内容和发展现状,分析了其切削参数,并着重介绍了高速切削的特点、高速加工对机床的要求及其在铝合金工件加工中的应用。     

Experimental and Analytical Based Investigations on Machinability of High-Chrome White Cast Iron Using CBN Tools

High-chrome white cast iron (HCWCI) is one of the hardest metals used in the process and mining industries faces tough challenge in metal cutting. Focusing on this issue, influence of cutting parameters (e.g., cutting speed, depth of cut, feed rate) on machinability characteristics (e.g., cutting forces, surface roughness, material removal rate, machining power) of HCWCI has been investigated by experimentally and analytically using cubic boron nitride (CBN) cutting tools. Experimentation is carried out in conjunction with the Taguchi techniques and the influence of each cutting parameter of the process has been analyzed by analytical tools; analysis of variance, regression technique and artificial neural networks (ANNs). The study reveals depth of cut has the highest contribution on the cutting forces, and cutting speed on surface roughness and machining power. The confirmation test identifies both regression and ANN techniques are the most effective tools to evaluate machinability characteristics of HCWCI. Further, the CBN cutting tool exhibits excellent performance in machining of HCWCI.     

The Effect of a Laser Beam on Chip Formation during Machining of Ti6Al4V Alloy

The effect of the laser beam on chip formation when machining Ti6Al4V alloy has been investigated at different cutting speeds and laser powers. The characteristics of the segmented chip produced by laser-assisted machining (LAM) in terms of the tooth depth and tooth spacing were strongly dependent on the cutting speed and laser power. Two types of segmented chip formation processes were observed, one at low and the other at high cutting speeds with a continuous chip occurring between these two types of segmented chips. The critical cutting speed at which the transition from the sharp, segmented chip to the continuous chip occurred increased with laser power. To obtain the continuous chip, plastic deformation at the shear zone to match the deformation strain introduced by the cutting tool is required. This can be achieved by laser heating the material in front of the cutting tool. A physical model is proposed to explain qualitatively the chip segmentation in conventional machining and the continuous chip transition at high cutting speed with the application of a laser beam.     

Effect of cutting parameters on cutting force and surface roughness in milling alumina reinforced Al–6Zn–2Mg–2Cu composites

Abstract

This paper presents the effect of main cutting parameters on cutting force and surface roughness in machining of alumina reinforced Al–6Zn–2Mg–2Cu composites. The composites were produced using powder metallurgy route. After an application of annealing heat treatment to these composites, their microstructural and mechanical characterisations were carried out. Then, machining was performed using the face milling operation with three different cutting tools and at various cutting speeds and feed rates for comparison. Results show that both cutting force and surface roughness increased with increasing the feedrate significantly. Furthermore, the cutting speed practically did not affect the cutting force in milling operation.     

Residual stresses after orthogonal machining of AlSl 304: numerical calculation of the thermal component and comparison with experimental results

Residual stresses due to the thermal influence of orthogonal machining have been calculated with a finite element model using stationary workpiece temperatures during cutting calculated with the finite difference method. Calculated results are compared with experimental data obtained with the X-ray diffraction method. In this way, the thermal and mechanical/frictional influences of the machining operation on the workpiece residual stress state can be separated. The influence of cutting speed and cutting depth on machining residual stresses is discussed. It is shown that the thermal as well as the mechanical impact of the orthogonal cutting process causes tensile residual stresses. The mechanical impact of the machining operation causing tensile residual stresses is due to (a) compressive plastic deformation in the surface layer ahead of the advancing tool and (b) greater elastic relaxation upon unloading with respect to the underlying material of a thin, strongly work-hardened surface layer. CHRISTOPH WIESNER, formerly Research Assistant with the Laboratoire de Métallurgie Mécanique, Ecole Polytechnique Fédérale de Lausanne, MX-D Ecublens, 1015 Lausanne, Switzerland.