钛合金结构件复杂翼面铣削加工工艺研究

针对钛合金结构件翼面装配弧面及定位槽的铣削加工,分析其加工工艺,对夹具进行针对性设计,在合理选择刀具材料的前提下优化刀具设计,改进工艺路径,最终完成了该钛合金结构件指定位置的铣削加工,在满足尺寸要求的同时提高了生产效率。     

航空发动机整体叶盘刀具性能灰色综合评价

以某型航空发动机钛合金整体叶盘的数控铣削为研究对象,提出了一种面向航空发动机整体叶盘的数控铣削刀具性能灰色综合评价方法。首先设计涵盖航空发动机整体叶盘难加工特征的基准件模型,然后基于灰色关联度分别构建了粗精加工刀具性能灰色综合评价模型,最后进行基准件的切削试验并应用所建立的灰色综合评价模型对刀具性能进行综合评价。研究结果表明,所构建的基准件模型和灰色综合评价模型可以快捷、有效地评价刀具性能。     

钛合金航空结构件导孔数字化加工方法

介绍了钛合金航空结构件导孔的数字化加工方法。通过对典型零件的加工试制,总结了钛合金航空结构件导孔的工艺流程制定、加工刀具选择、切削参数设定、定位方法、装夹方式等数字化制造工艺。     

基于铣削力参数化模型的铣刀非均匀磨损状态监测方法研究

在航空结构件钛合金零件数控加工中,刀具非均匀磨损状态对工件的最终质量影响很大。为了及时发现并控制因刀具非均匀磨损导致的异常加工状态,对钛合金加工刀具非均匀磨损状态监测方法进行了研究。建立了基于刀具刃线参数化模型的铣削力参数化模型,实现了对钛合金加工刀具非均匀磨损状态的监测,解决了零件单件或首件加工中样本数据缺失条件下的钛合金加工刀具非均匀磨损状态准确监测难题。     

航空航天难加工材料的高速铣削

正山特维克可乐满新推出的CoroMill~?Plura HFS ISO S刀具是加工钛合金和镍基合金航天航空零件的理想之选。为了提高ISO S材料的铣削性能,切削刀具和刀具系统专家山特维克可乐满推出了一系列具有独特槽型和材质的立铣刀。CoroMill~?Plura HFS(高进给侧铣)ISO S刀具可确保钛合金和镍基合金工件的加工可靠且富有成效,在航空发动机和结构件应用中均有不俗的表现。     

钛合金铣削加工刀具磨损有限元预测分析

钛合金Ti6Al4V因其优良的综合性能在航空航天领域有着广泛的应用。然而,在钛合金切削过程中,极易出现刀具磨损现象。目前尚缺乏钛合金加工用刀具寿命预测的有效手段和方法。针对这一问题,基于刀具在铣削工作过程中受到的热力耦合作用,利用Fick扩散定律揭示了刀具扩散磨损机理,构建刀具磨损模型;利用有限元仿真软件Advant Edge的二次开发技术,将刀具磨损模型嵌入到有限元模型中,进行刀具磨损的预测;进而借助刀具寿命试验,验证了刀具磨损模型的可靠性。     

航空钛合金Ti6Al4V微细铣削加工数值模拟与试验研究

根据实际微细铣削加工方法,采用DEFORM软件建立螺旋立铣刀铣削加工分析模型,利用该模型分析硬质合金刀具铣削加工航空用钛合金Ti6Al4V过程中的铣削力变化,在相同条件下进行铣削加工试验。试验结果表明:随着铣削的进行,刀具与切屑逐步接触,各个铣削方向切削力逐渐增加;随着铣削的进行,切削厚度逐渐减小、铣削温度升高、工件材料力学性能和铣削力开始降低;铣削深度、单齿进给量及铣削速度对铣削力均有不同程度的影响,其中单齿进给量影响最大。     

CAM环境下飞机结构件加工刀具及切削参数自动推送技术研究

加工刀具及切削参数选择作为工艺决策的重要环节,目前仍依赖人工经验,严重影响工艺决策质量和效率。针对上述问题,提出了一种基于模糊综合评判法的加工刀具及切削参数决策方法,基于历史加工数据从刀具属性、加工状态和加工效果三方面对数据库中加工刀具及对应的切削参数进行综合评价,从而实现加工刀具与切削参数的优选,通过CAA开发技术,实现了在CAM环境下的加工刀具及切削参数自动推送,有效提升了工艺设计效率和质量,通过飞机典型结构件应用案例表明了方法的有效性。     

基于正交试验法的钛合金铣削工艺参数优化及应用

在钛合金航空结构件生产中，刀具成本是制造成本的重要组成部分。针对新材料、新工具与旧工艺参数不匹配的问题，设计了钛合金铣削工艺参数优化方案，建立基于制造成本的评价模型，通过对有重复试验的正交试验结果进行数据分析，在寻找出局部最优解的同时明确各项工艺参数的影响，为后期持续优化改进奠定基础。     

钛合金铣削加工电磁强化刀具耐用度研究

针对钛合金飞机结构件难加工特性导致刀具磨损、破损严重的问题,本文研究了电磁强化技术对钛合金铣削加工硬质合金刀具耐用度的影响,通过进行电磁强化可转位刀片铣削加工钛合金槽腔的试验,采集加工过程的切削弯矩数据,观测刀具磨损形貌,绘制了刀具磨损曲线,建立了切削弯矩与切削时间的映射关系.对未电磁强化和电磁强化刀具的耐用度进行对比...     

数控基准转换模式在大功率船用低速柴油机零件机架加工中的应用

通过对大功率船用低速柴油机零件机架的工艺分析,结合大型数控龙门铣床对腔体类零件的加工特点,融合刀具、工装及数控编程等多领域技术,形成了一套数控基准转换模式的机架加工方案,其有效规避了大型机床操作工的登高作业风险,使零件加工基准统一,机床加工干涉透明,人机互动简单易控。     

Analysis model of parameters affecting cutting performance in high-speed machining

Further progress in green cutting applications depends on the innovativeness of machine tools, advances in tool development, and, especially, more complex tool and cutting technologies. Therefore, this study analyzes the factors influencing high-speed cutting performance. Grey relational analysis and the Taguchi method are then incorporated in the experimental plan with high-speed milling of AISI H13 tool steel. Experimental results indicate that the contributions of tool grinding precision, geometric angle, and cutting conditions to the multiple quality characteristics of high-speed milling for AISI H13 tool steel are 11.75, 9.80, and 73.11 %, respectively. For rough machining, tool life and metal removal volume are the primary evaluation indicators and cutting parameters should be prioritized, especially cutting speed and feed per tooth. In finish machining, workpiece surface roughness is the primary evaluation indicator. Besides the selection of cutting parameters, the design and grinding of endmill are critical factors, especially the design and grinding of relief angles.     

Milling Force Model for Aviation Aluminum Alloy:Academic Insight and Perspective Analysis

Aluminum alloy is the main structural material of aircraft,launch vehicle,spaceship,and space station and is pro-cessed by milling.However,tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy.The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters,material mechanical properties,machine tools,and other parameters.In particular,milling force is the crucial factor to determine material removal and workpiece surface integrity.However,establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system.The research progress of cutting force model is reviewed from three modeling methods:empirical model,finite element simulation,and instantaneous milling force model.The problems of cutting force modeling are also determined.In view of these problems,the future work direction is proposed in the following four aspects:(1)high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth,which easily produces high residual stress.The residual stress should be analyzed under this particular condition.(2)Multiple factors(e.g.,eccentric swing milling parameters,lubrication conditions,tools,tool and workpiece deformation,and size effect)should be consid-ered comprehensively when modeling instantaneous milling forces,especially for micro milling and complex surface machining.(3)The database of milling force model,including the corresponding workpiece materials,working condi-tion,cutting tools(geometric figures and coatings),and other parameters,should be established.(4)The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling.(5)The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication(mql)and nanofluid mql should be predicted.     

Wear characteristics of diamond tool in ultraprecision raster milling

Ultraprecision freeform raster milling is a very complex machining process, and long machining time is used for small components. Therefore, the diamond tool wear is a crucial factor that not only raises the machining cost but also limits the cutting performance in ultraprecision raster milling. In this paper, the methods of process monitoring and wear evaluating of single-crystal diamond tools during the raster milling of copper are studied in two types of cutting environment: with lubrication and without lubrication. Experimental results indicate that the impact and free vibration are important dynamic characteristics in raster milling process that result in the obvious microchipping wear on the cutting edge.     

Investigations on model-based simulation of tool wear with carbide tools in milling operation

This paper deals with tool wear in milling operation using carbide tools. The main purpose of this work is to define a model-based procedure for forecasting tool-wear progression during cutting operation by using machining simulation. Firstly, a multi-axis machining simulation algorithm is proposed based on DEXEL model and local area update method. NC milling machining process simulation software NCToolWearSim is realized by using Visual C++ and OpenGL. The developed process simulation software is used to simulate the cutting process. Secondly, tool-wear simulation algorithm in the machining process is presented with tool-wear model and machining simulation algorithm and is implemented into the machining simulation software NCToolWearSim in order to evaluate the tool wear and to update the tool geometry. The tool-wear value is estimated according to the established tool-wear model from experienced tool-wear data. Thus, tool-wear progression can be visualized in milling operation by using NCToolWearSim. Finally, experimental tests, performed milling integral wheel with carbide tools, were used to calibrate and validate the correctness of tool-wear simulation process based on the tool-wear model.     

Progressive tool failure in high-speed dry milling of Ti-6Al-4V alloy with coated carbide tools

This paper presents a detailed analysis of tool failure progression through an experimental study of high speed milling of Ti-6Al-4V alloy with CVD (Ti(C, N)-Al₂O₃)-coated carbide tools. The progressive tool failure characteristics under a variety of different cutting conditions were investigated. Cutting forces components and transient infrared temperature during the machining processes have been measured along with corresponding progressive tool wear when milling using coated carbide inserts under dry machining conditions. Optical microscope and scanning electron microscopic analysis results clearly show the different dominant wear regions at different stages of machining with coated carbide tools. The experimental results demonstrate that the cutting forces and the cutting temperature produced during the machining process showed an increasing trend with the tool failure progression, which in turns accelerated the tool wear progression and caused the change of the tool failure mechanisms. Furthermore, the progressive tool failure mechanisms were analyzed qualitatively. The cutting speed was correlated with progressive tool failure mechanisms, and the different conditions of friction and normal stresses caused by different cutting force and cutting temperature under different cutting speeds resulted in the varieties of progressive tool failure mechanisms.     

基于综合评价体系的五轴数控机床加工性能评价和误差溯源方法

五轴数控机床的加工性能在制造行业一直是研究的热点,基于检验试件切削是常见的测评方法,然而试件和机床之间的映射关系难以确定,出现误差后如何调整精度成为难点。为了科学对其评价,通过仿真平台建立了机床控制系统参数与五轴机床检验试件——S试件加工误差之间的映射关系,引入机床各轴分类评价的隶属度,此基础上开发了误差溯源的综合评价体系,由三坐标测量机得到的S件轮廓误差数据反求出机床的加工性能等级和较差的轴类控制参数,并制订了基于S试件的机床加工精度测评规范,最后通过某五轴AB摆数控机床的切削试验,验证了方法的有效性。该成果有助于解决我国高端制造业长期缺乏机床性能测评的共性技术问题,具有重要的应用前景和经济价值。     

涂层刀具推动数控加工发展

高速切削、硬态加工、高稳定性加工、以车代磨、干式切削等新型切削方式对数控刀具提出了更高的要求,刀具涂层技术自问世以来,对刀具性能的改善和加工技术的进步起着非常重要的作用,涂层刀具已经成为现代刀具的标志。数控机床加工工件时,合理选用刀具材料不仅可以提高刀具切削加工的精度和效率,而且也是对难加工材料进行切削加工的关键措施,可以说在影响金属切削效率的诸多因素中,刀具材料是主要因素,起着决定性作用。     

Microgrooving on electroless nickel plated materials using a single crystal diamond tool

Diamond tools are used in ultra precision machining for their outstanding hardness and crystalline structure, which enable the fabrication of very sharp cutting edges. Single crystal diamond tools are thus extremely useful to machine electroless nickel-plated dies which are generally used for making molds for optical components. This paper deals with the objective to evaluate the performance and suitability of a single crystal diamond tool during microgrooving on electroless nickel plated workpieces. Effects of different machining parameters on overall machining performance were also investigated. The experimental results revealed that long distance (50 km) machining of microgrooves on electroless nickel is possible with a single crystal diamond tool without any significant tool wear. Some groove wear on the rake face were found after machining 28.5 km. No evidence of chipping or wear had been observed on the flank face during the total machining length. The surface roughness range of the machined workpieces was found to be 4–6 nm. Both thrust and cutting components of the machining forces showed an increasing trend with increasing machining distance, though magnitude of the thrust forces were found to increase more than the cutting forces.