铝合金2024-T3超精密车削仿真与切屑观察

铝合金具有易加工、质量轻、反射性良好等特点,是反射镜制造的常用材料。铝合金经过单点金刚石超精密车削后得到表面粗糙度为纳米级的镜面零件。为深入研究超精密车削机理,提高超精密车削铝合金零件的质量,本文选用Advant Edge对铝合金2024-T3的超精密车削过程进行模拟仿真,对超精密车削的切削力、尺寸效应进行分析。使用超精密车床,采用天然单晶金刚石刀具对铝合金2024-T3进行微米及亚微米的超精密车削,并使用扫描电镜(SEM)对样件的切屑进行观察。     

精密、超精密车削刀具的材料

精密、超精密车削是先进制造技术中最重要的加工工艺方法之一 ,而刀具材料是实现该工艺的关键。现结合国内外目前研究状况 ,对精密、超精密车削的刀具材料种类、性能进行综合评述     

精密、超精密车削刀具的材料

精密、超精密车削是先进制造技术中最重要的加工工艺方法之一，而刀具材料是实现该工艺的关键，现结合国内外目前研究状况，对精密、超精密车削的刀具材料种类，性能进行综合评述。     

超精密加工中刀具参数对脆性材料非球面加工质量的影响

脆性材料的光学非球面零件以其特有的优势,在军用和民用产品中越来越普及.光学非球面器件材料有一系列不利于加工的特点,被公认为是最难加工的光学零件.概述了超精密加工中单点金刚石车削技术在脆性材料非球面加工中的应用,并详细地分析了单点金刚石车削加工时刀具几何参数、X偏置、刀具半径补偿对非球面加工表面质量的影响.     

超精密慢刀伺服车削零件的面型分析与刀具设计方法研究

研究首先分析总结了当前自由曲面复杂零件超精密慢刀伺服车削加工中的具体加工技术挑战,进而系统地研究了自由曲面零件面型特性,零件面型关键参数提取,零件面型参数与刀具参数之间的关联关系。进一步研究了超精密慢刀伺服车削金刚石刀具的几何参数确定方法;并针对自由曲面零件的可加工性,提出了超精密慢刀伺服车削加工中金刚石刀具选用准则。另外,通过超精密慢刀伺服车削加工实际案例和应用加工试验,证明零件面型分析及金刚石刀具几何参数的合理选用,对实现高效稳定的工业化超精密慢刀伺服车削加工至关重要。     

超精密加工中刀具参数对脆性材料非球面加工质量的影响

脆性材料的光学非球面零件以其特有的优势,在军用和民用产品中越来越普及。光学非球面器件材料有一系列不利于加工的特点,被公认为是最难加工的光学零件。概述了超精密加工中单点金刚石车削技术在脆性材料非球面加工中的应用,并详细地分析了单点金刚石车削加工时刀具几何参数、X偏置、刀具半径补偿对非球面加工表面质量的影响。     

难加工材料车削中精密内冷却对刀具寿命的影响

针对GH901高温合金材料、06Cr19Ni10奥氏体不锈钢材料和20Cr1Mo1VNbTiB合金钢材料在精密内冷却和外冷却方式下进行的刀具失效形式及刀具寿命对比车削试验发现,相较于常规外冷却车削,精密内冷方式的刀具寿命有较大幅度提升,车削GH901材料可以提升48.93%刀具寿命,车削06Cr19Ni10材料能提升34.73%刀具寿命,车削20Cr1Mo1VNbTiB材料能提升28.57%刀具寿命;在连续切削工况下进行车削试验,刀具失效方式为后刀面磨损。     

异型截面零件的切削加工技术

介绍了异型截面零件的加工方法及特点,重点介绍了异型截面零件的精密车削和砂带磨削加工技术。分析了车削加工时刀具角度的变化及改进措施。     

高效硬车削

采用传统加工方式,材料硬度达到或超过45HRC的零件,需要采用专用的磨削设备和工艺加工。随着机床和切削刀具技术的发展,为零件制造商提供了更多的新工艺方法,越来越多的制造商在探索适合他们的新加工方案。相对于磨削加工,硬零件车削具有几方面的优点:一般来说,车削中心的成本低于精密磨床,并可在同一机床上加工零件的多部位,大大提高了操作的灵活性;减少了刀具库存,而且车削中心比磨床更容易与自动化系统集成。此外,车削过程产生的切屑是可以被再利用的,     

AM60镁合金超精密车削残余应力的有限元分析

为改善AM60镁合金精密零件加工工艺方法,对镁合金精密零件的超精密加工进行微米级仿真研究。采用解析和有限元仿真法,利用Advant Edge软件进行车削加工模拟,得到刀具参数和切削参数对已加工表面残余应力的影响规律,并建立加工材料残余应力经验模型。结果表明:切削力对残余应力的产生起主导作用,随着切削参数的改变,切削温度变化不明显,对残余应力的影响较小。仿真结果满足制造精度要求,为提高镁合金精密工件的质量和性能打下了理论基础。     

切削铸铁的刀具用新材料

介绍了选择铸铁切削用刀具需考虑的因素,可用于不同牌号铸铁的切削用刀具新材料有硬质合金刀具、陶瓷刀具、金属陶瓷刀具和超硬刀具。用于铸铁切削的整体硬质合金刀具的研究和应用成果各有两项,涂层硬质合金新材料有3种,陶瓷刀具和超硬刀具研究不多,研究最多的是金属陶瓷刀具,尤其是纳米金属陶瓷刀具材料。     

金属陶瓷刀具切削难加工材料时的磨损性能研究

对金属陶瓷刀具和YG8刀具切削冷硬铸铁和不锈钢时的磨损性能进行了对比切削试验 ,结果表明 :切削冷硬铸铁时金属陶瓷刀具的寿命明显低于YG8刀具 ,而切削不锈钢时金属陶瓷刀具的寿命高于YG8刀具。金属陶瓷刀具的失效形式主要为崩刃     

微米／纳米复合Ti（C，N）基金属陶瓷刀具切削铸铁的性能研究

利用热压烧结法制备了微米／纳米复合Ti（C,N）／Al2O3金属陶瓷刀具,对研制的三种金属陶瓷刀具（材料编号JT1-JT3）和YG8硬质合金刀具切削铸铁时的切削性能进行了试验研究。结果表明,研制的金属陶瓷刀具适合切削铸铁,其切削性能优于YG8,尤其是JT2刀具不但磨损较小,且加工表面质量较好。分析了刀具的磨损形貌和磨损机理,得出了Ti（C,N）金属陶瓷刀具的主要磨损机理为后刀面磨粒磨损的结论。     

The performance of ceramic and cermet cutting tools for the machining of austempered ductile iron

In this study, the machinability of austempered ductile iron (ADI) having a ferritic structure was examined. For this purpose, three types of ductile iron materials (as cast, ADI-250, ADI-375) and two different types of cutting tool materials (ceramics and cermet) were used. To emphasize the role of austempering process, ductile iron (DI) specimens are first austenitized in salt bath at 900°C for 120 minutes after which they are quenched in salt bath at 250°C (ADI-250) and 375°C (ADI-375) for 120 min. Machining tests were carried out at various cutting speeds (100–500 m/min) under the constant depth of cut and feed rate. The performance of both ceramic and cermet tools were evaluated based on the workpiece surface roughness and flank wear. Wear conditions of the cutting tools were characterized by scanning electron microscope. The results point out that the lower austempering temperature results in increasing of the cutting forces, while better surface roughness is obtained. Additionally, the results indicate that the tool wear occurs mainly on the flank face. However, higher cutting speed results in chipping formation in cermet cutting tool.     

MACHINING PARAMETERS OPTIMIZATION FOR ALUMINA BASED CERAMIC CUTTING TOOLS USING GENETIC ALGORITHM

Alumina-based ceramic cutting tools can be operated at higher cutting speeds than carbide and cermet tools. This results in increased metal removal rates and productivity. While the initial cost of alumina based ceramic inserts is generally higher than carbide or cermet inserts, the cost per part machined is often lower. Production cost is the main concern of the industry and it has to be optimised to fully utilize the advantages of ceramic cutting tools. In this study, optimization of machining parameters on machining S.G. iron (ASTM A536 60-40-18) using alumina based ceramic cutting tools is presented. Before doing the optimization work, experimental machining study is carried out using Ti [C,N] mixed alumina ceramic cutting tool (CC 650) and Zirconia toughened alumina ceramic cutting tool (Widialox G) to get actual input values to the optimization problem, so that the optimized results will be realistic. The optimum machining parameters are found out using Genetic algorithm and it is found that Widialox G tool is able to machine at lower unit production cost than CC 650 tool. The various costs affecting the unit production cost are also discussed.     

MACHINING PARAMETERS OPTIMIZATION FOR ALUMINA BASED CERAMIC CUTTING TOOLS USING GENETIC ALGORITHM

Alumina-based ceramic cutting tools can be operated at higher cutting speeds than carbide and cermet tools. This results in increased metal removal rates and productivity. While the initial cost of alumina based ceramic inserts is generally higher than carbide or cermet inserts, the cost per part machined is often lower. Production cost is the main concern of the industry and it has to be optimised to fully utilize the advantages of ceramic cutting tools. In this study, optimization of machining parameters on machining S.G. iron (ASTM A536 60-40-18) using alumina based ceramic cutting tools is presented. Before doing the optimization work, experimental machining study is carried out using Ti [C,N] mixed alumina ceramic cutting tool (CC 650) and Zirconia toughened alumina ceramic cutting tool (Widialox G) to get actual input values to the optimization problem, so that the optimized results will be realistic. The optimum machining parameters are found out using Genetic algorithm and it is found that Widialox G tool is able to machine at lower unit production cost than CC 650 tool. The various costs affecting the unit production cost are also discussed.     

TiC(N)基金属陶瓷刀具材料的制备与切削性能研究

制备了一种新型TiC(N)基金属陶瓷刀具材料 ,并通过加工冷硬铸铁、4 5钢的对比切削试验 ,分析研究了它的切削性能     

纳米TiN改性的TiC基金属陶瓷刀具切削试验与分析

通过切削试验 ,研究了纳米TiN改性的TiC基金属陶瓷刀具在切削 40Cr和正火态 45钢时的切削性能和失效形式。结果表明 ,该种刀具有良好的切削性能 ,可用于较高速度下钢的切削 ,其主要失效形式为磨损。     

Edge micro-creation of Ti(C,N) cermet inserts by micro-abrasive blasting process and its tool performance

Abstract

In this study, the cutting edge passivation by a micro-abrasive blasting method for cermet inserts and its machining performance were investigated. The micro-abrasive blasting parameters for cermet inserts were optimized and the micro-creation of cutting edge was determined with detail. A Back Propagation (BP) neural network prediction model was further established based on our micro-abrasive blasting experiment datum, which can directly evaluate the micro-abrasive blasting ability to generate the specific edge radius. The improvement of cutting performance of micro-abrasive blasted cermet inserts benefits from the strengthening of cutting edge that caused by the obvious elimination of a large number of micro-defects rooted around the edge, and the formation of circular cutting edge is the result of brittle removal and plastic removal. The micro-creation of inserts can acquire a circular cutting edge, and the optimal edge radius is 15?μm under the selected cutting conditions when the tool life was chosen as an optimization target and the surface roughness was simultaneously taken into account. It is found that the blasted cermet inserts can prolong the tool life by at least 86% and the machined-surface quality can be improved by up to 1.65?μm, compared to inserts without micro-abrasive blasting.     

性能优异的切削刀具材料——金属陶瓷

分析比较了金属陶瓷材料的性能特点 ,介绍了超细微粒金属陶瓷、涂层金属陶瓷、超韧金属陶瓷等新型金属陶瓷刀具材料的切削性能及适用范围。