高速铣削刀具在高速切削加工中的应用

高速切削加工中,刀具是直接影响加工质量、生产效率和加工成本的重要因素.文章分析和讨论了高速铣削加工中刀具材料、刀具涂层以及刀具的结构参数等对刀具性能的影响;并以一零件加工为例,分析和介绍了高速铣削时其刀具的选用,以及通过刀具提高零件加工精度、表面质量和加工效率的技术方法.     

基于MasterCAM X6的高速切削优化

针对传统零件加工刀具容易磨损、影响加工效率、零件表面质量差等缺点。本文介绍应用MasterCAM X6高速加工刀具路径的参数优化点,可以一定地提高加工效率、同时相对传统刀具路径有很大的优化,减少刀具磨损,延长刀具寿命。     

数控加工深型腔复杂型面模具的刀具长度优化

介绍数控加工深型腔复杂型面模具时刀具长度优化的几种方法,通过最短刀具长度的计算、旋转零件降低型腔深度、拆分零件加工模具以及使用刀具加长杆和角度头,实现缩短加工刀具的长度、优化加工手段,提高模具的加工精度、质量和效率。     

Research Progress of Diamond Tool Machining Technology for Ferrous MetalsEI北大核心CSCD

金刚石刀具是超精密加工最理想的刀具之一,但在黑色金属超精密加工领域“石墨化”导致刀具快速磨损,其应用极大地受到了限制。首先,针对金刚石刀具的磨损机理进行介绍。然后,综述金刚石刀具切削黑色金属的几种常见方法,如刀具表面改性、工件表面改性、低温辅助切削、超声振动辅助切削等,通过研究实例来分析各方法的应用效果和存在问题,并从技术层面分析影响金刚石刀具在黑色金属加工领域发展的关键因素。最后,对金刚石刀具切削黑色金属未来的发展趋势进行探讨。总结金刚石刀具在黑色金属领域的加工方法,分析加工黑色金属时抑制金刚石刀具磨损的核心技术,对黑色金属的精密超精密加工具有重要的引领和推动作用。     

基于平面砂轮的面齿轮数控切、磨齿技术

传统上面齿轮的加工都是基于小齿轮与其啮合的模拟,导致刀具没有通用性,加工过程复杂,针对这一问题,借助数控技术,提出了采用平面刀具加工面齿轮的方法。首先论述了平面刀具的设计、平面刀具展成加工面齿轮的原理,并结合格林森的技术,提出了平面刀具加工面齿轮所需运动配置。其次通过数学推导,建立了平面刀具加工面齿轮的数学模型,并进行了数控转换。最后对平面刀具加工面齿轮的理论方法及其数控方法进行了仿真模拟,模拟表明:采用平面刀具加工面齿轮可获得理论齿面,其数控加工方法的齿面误差可小达2.56μm。     

编制CNC数控机床程序应注意的若干问题

CNC数控机床的加工控制归根到底是由使用它的工艺人员、操作人员来控制的,其媒介就是数控加工程序.人们要利用数控机床完成高精度的零件加工,就必须编制合理的数控加工程序(手工或利用软件编制)、调整机床等基本操作.根据欲加工零件特点,数控机床的加工范围,合理选择数控设备;编程时应根据加工零件的特点、材料、精度要求、机床和刀具的刚度,采取刀具补偿;编制程序时必须考虑刀具的补偿方式,刀具的切入切出,应使其能够平滑过渡.使刀具沿工件的直线延长线或圆弧的切线方向切入切出.落刀点尽可能选在加工实体的外面,特别是小刀具切削时.当加工平面变化或加工完成时,应注意抬起刀具.注意固定循环指令的使用.在加工过程中应合理使用,以提高加工效率.     

切削难加工材料的解决方案——PCD和CBN刀具

聚晶金刚石（PCD）刀具和立方氮化硼（CBN）刀具为难加工材料的切削难题提供了解决方案。对切削刀具材料中这两种先进概念刀具的加工挑战已尽人皆知。不同设计的CBN刀具被用于对淬硬黑色金属进行连续或断续切削,以及切削加工焊接金属和复合金属。而PCD刀具被广泛应用于铣削有色金属、复合材料、塑料以及极其难加工的超级合金。     

缸体加工表面质量和切削刀具的常见问题和对策

在长期工作经验的基础上,介绍机械加工过程中影响发动机缸体加工精度和刀具寿命的各种工艺因素,分析缸体生产中常见缺陷和刀具磨损的原因;根据对切削刀具的分析,提出从刀具入手解决缸体切削加工问题的思路,以及合理选择刀具材料、确定刀具合理的几何参数、合理的切削参数、刃磨刀具、冷却润滑的一般原则及方法。并给出了提高缸体加工精度和改善刀具寿命的主要途径。     

高压连接杆数控加工及刀具优化

针对高压连接杆零件数控加工特点,基于其加工工艺,研究了其加工刀具的选择和参数的设定,有效地解决了该零件因刀具选用不合适而带来的刀具消耗大、加工效率低、成本高等问题。     

新型刀具材料与切削工艺的变革

本文采用大量的数据,对采用新型刀具材料及传统刀具材料时切削加工效率、质量及刀具寿命等技术与经济问题进行了对比分析,说明了新型刀具材料必然要取代传统刀具材料。新型刀具材料的应用将促进机床制造技术的不断革新、切削加工工艺的相互替代及切削加工工艺流程的变革。刀具材料的发展方向是:(1)开发含有氮化物的新型刀具材料;(2)发展涂层刀具;(3)改善刀具基体,采用细晶粒硬质合金来提高刀刃强度。高速—精密切削加工技术是切削加工技术发展的必须趋势。图2幅。     

旋转超声辅助加工装置及其工艺研究

基于传统超声振动理论,提出了一种新型旋转超声辅助加工装置。该装置将超声振动与负载匹配二者相结合,具备旋转超声辅助加工硬脆材料的能力。利用该装置对微波铁氧体材料进行旋转超声辅助钻削加工试验研究,验证了旋转超声辅助磨削可有效降低加工过程中的切削力。同时,在保证刀具和材料安全的前提下,探索了旋转超声辅助加工装置对加工效率的影响。     

新型陶瓷刀具的发展与应用

回顾了陶瓷刀具的发展简况及其意义,重点介绍了Si3N4基和TiCN基复合陶瓷刀具的研制、性能和应用.复合Si3N4陶瓷刀具有较高的耐磨性和抗冲击性,特别适合于各类铸铁件的粗精加工,也能进行铣削、刨削等冲击力很大的加工,其切削效率可提高3～10倍;复合TiCN金属陶瓷刀具具有很高的硬度和耐磨性,特别适合于各类高硬高强钢(如淬硬钢等)的加工,可对高硬材料实现"以车代磨"干切削,免除退火工艺和冷却液,大幅度提高生产效率.新型复合陶瓷刀具已经在我国冶金、水泵、矿山机械、轴承、滚珠丝杠、汽车、军工等十几个行业得到应用.     

Surface integrity when machining age hardened Inconel 718 with coated carbide cutting tools

Considerable attention has been given to the use of ceramic cutting tools for improving productivity in the machining of heat resistant super alloys (HRSA). However, because of their negative influence on the surface integrity, ceramic tools are generally avoided particularly for finishing applications. As a result the main high end manufacturers are more or less dependent on carbide cutting tools for finishing operations. Still the improper use of carbide cutting tools can also result in poor surface integrity. The objective of this investigation is to develop a set of guidelines, which will assist the selection of the appropriate cutting tools and conditions for generating favorable compressive residual stresses. This paper specifically deals with residual stresses and surface finish components of surface integrity when machining (facing) age hardened Inconel 718 using two grades of coated carbide cutting tools specifically developed for machining HRSAs. The cutting conditions were obtained from investigations based on optimum tool performance. The effect of insert shape, cutting edge preparation, type and nose radius on both residual stresses and surface finish was studied at this optimum cutting condition. This investigation, suggested that coated carbide cutting tool inserts of round shape, chamfered cutting edge preparation, negative type and small nose radius (0.8 mm) and coolant will generate primarily compressive residual stresses.     

Tool life and wear mechanisms in high speed machining of Ti–6Al–4V alloy with PCD tools under various coolant pressures

Usage of titanium alloys has increased since the past 50 years despite difficulties encountered during machining. Many studies involving different tool materials, cutting parameters, tool geometry and cutting fluids when machining this important aerospace material have been published. However, there are relatively few literatures available on the application of ultra hard tools in the machining of titanium-alloys. The primary objective of this study is to investigate the behaviour of Polycrystalline Diamond (PCD) tools when machining Ti–6Al–4V alloy at high speed conditions using high pressure coolant supplies. Tool performance under different tribological conditions and the dominant wear mechanisms were investigated. Increase in coolant pressure tends to improve tool life and reduce the adhesion tendency, accelerated by the susceptibility of titanium alloy to gall during machining. Adhesion and attrition are the dominant wear mechanisms when machining at the cutting conditions investigated.     

Prediction of tool life for restricted contact and grooved tools based on equivalent feed

This paper begins with a review of the recently developed semi-empirical methods for predicting cutting forces and tool life in machining with restricted contact (RC) and grooved tools which have used Oxley’s machining theory as a basis. The paper then presents a new method for predicting the tool life (based on flank wear) for RC/grooved tools using an equivalent feed based on the cutting force for the RC/grooved and corresponding plane face tools. The required cutting force and tool temperature for the plane face tool are determined from Oxley’s theory. This new method has been applied for RC and grooved tools. A comparison between predicted and experimental results shows good agreement.     

Experimental study on ultrasonic elliptical vibration cutting of hardened steel using PCD tools

Diamond tools cannot usually be applied for machining hardened steels while applying conventional cutting technique. As an alternative, ultrasonic elliptical vibration cutting (UEVC) technique was successfully applied for obtaining mirror surface on such steels using single crystal diamond (SCD) tools. In order to reduce production cost without compromising mirror surface quality, polycrystalline diamond (PCD) tools may be tested against highly expensive SCD tools. However, study on machining of hardened steel using PCD tools applying the UEVC technique has not yet been reported. The current research presents an experimental study on UEVC of hardened stainless steel (a typical Stavax, hardness 49 HRC) using the PCD tools. Face turning experiments were carried out to investigate the effects of three machining parameters: nominal depth of cut, feed rate, and nominal cutting speed on output performances such as cutting force, tool flank wear, surface roughness, and chip formation. Experimental results show that nominal cutting speed has very strong influence on the output performances, compared to the other two parameters. The surface roughness improves with a decrease in cutting speed. A mirror-like surface of approximately 804 mm² with a roughness value R_a of 11 nm was achieved at a lower cutting speed. Theoretical explanations have been given to support the results drawn from the UEVC experiments. It can be concluded that, while applying the UEVC technique, the inexpensive PCD tools instead of the SCD tools can be effectively applied to obtain optical surface for producing precise molds from the hardened steel.     

A model to calibrate and predict forces in machining with honed cutting tools or inserts

This paper describes a mechanistic approach towards modeling the effects on machining forces of the edge hone commonly ground on machining tools and tool inserts. This approach proposes that the ratio of the shearing to ploughing forces would remain identical for tools with different honed radii, machining under identical conditions of chip thickness to edge hone radius ratios and cutting velocity. This concept allows a very simple and new calibration technique toward separating out the effects of tool and machining parameters that influence the force coefficients in machining without a need for any additional parameters. The model has been presently developed for orthogonal cutting and its validation using a tube turning process on gray cast iron with straight edged inserts has shown very promising results. Continued research is being performed to evaluate the applicability of the model for more complex machining operations.     

On the machining of alumina and glass

Machining of electrically non-conducting materials like alumina and glass is still a major problem. Electrochemical spark machining (ECSM) process is a potential process for machining these materials. However, ECSM has its own inherent limitations. So far, only ordinary cutting tools have been used during ECSM by previous researchers, but the results obtained are not as good as anticipated. In the present work, electrochemical spark abrasive drilling (ECSAD) experiments have been conducted using abrasive cutting tools, with a view to enhance the capabilities of the process. Use of an abrasive cutting tool, when compared to a conventional cutting tool, has been found to improve the process performance, viz. enhanced material removal and increased machined depth. The workpiece materials used are alumina and borosilicate glass.     

硬质合金刀具干式切削力的仿真

切削力是刀具切削性能评价的重要指标之一 ,本文提出了一种建立在MATL AB系统上的切削力预报系统 ,它可以十分方便的预报硬质合金刀具切削普通碳素钢的切削力变化规律 ,切削力预报精度较高 ,可以应用于新刀具的开发、生产和设计中     

基于多色集合理论的数控加工刀具优化选择研究

基于建立刀具选择的关系模型并以围道布尔矩阵的形式表示,通过多色集合中着色的逻辑运算,找到满足加工条件的候选刀具集合并对其进行模糊优选;综合考虑换刀时间,加工顺序以及其它相关加工信息对刀具选择的影响,使选择刀具在整体上达到最佳化。