难加工材料的切削技术

在现代生产工程中，各种新型材料（包括金属和非金属）的应用日益广泛。其中有不少材料是难加工的。本文论述各种难加工材料的切削加工特点及其加工技术的新发展，对生产有一定指导作用。一、现代难加工材料的种类随着航天航空工业、核工业、兵器工业、化学工业、电子工业以及现代化机械工业的发展，对产品零部件材料的性能有着各种各样的特殊要求。有的在高温、高应力状态下工作，有的要耐腐蚀、耐磨损，有的要能绝缘，有的则需有病导电率。故现代新的工程材料形形色色，多种多样，不断涌现。不仅使用一般的碳素结构钢，而且使用了高强度钢…     

残余应力对切削加工精度的影响及消除

探讨了机械制造过程中残余应力的形成原因及对机械零部件切削加工精度的影响,通过对车削、铣削等常用机加工过程中残余应力的形成以及对加工品质、使用寿命、失效形式的分析,有针对性地采取了有效措施,减小残余应力的产生,消除残余应力,从而改善加工品质,提高工件的切削精度和使用寿命。     

切削参数与刀具几何形状对Inconel 718加工残余应力的影响

对Inconel 718高速切削加工过程中合金加工表面的残余应力进行研究,为优化材料切削参数提供参考。由试验结果可知,最大切削速度、最小进给量、中等切削深度和使用珩磨切削刃可以确保减少加工表面的残余应力,相应的表面也没有划痕区和粘附的碎屑。     

难加工材料的切削加工研究

分析了难加工材料切削时刀具材料的选用原则,对典型难加工材料的切削进行了研究,包括难加工材料的特性以及刀具材料及其几何参数的合理选择,对难加工材料的切削加工有一定的帮助和指导作用.     

浅谈难加工材料的低温切削

针对难加工材料的切削加工性,提出了改善其加工性能的方法.重点对低温切削加工方法进行了介绍,包括低温切削技术的特点及其制冷技术,最后阐述了机械制造领域中低温切削技术的研究成果.     

难加工材料的切削技术

现代制造领域中各种轻质强韧、Waspaloy、In－conel与Hastelloy超耐热合金等折材料不断问世,从其制造成各种零件的加工工艺来看,多数材料需要切削加工。这些材料按被切削加工成合格零件的难易程度分析,又大多属于难加工材料。因此,研究难加工材料的切削机理、掌握切削规律,提高切削效率,保证加工精度与表面质量及降低制造成本,是当代金属切削技术面临的重要课题。一、切削特性与存在问题难加工材料的切削加工性是由其常温特别是高温状态下的物理力学性能决定的。它与材料的化学成分与金相组织状态有关,也与切削加工时所用的刀具材…     

几种难加工材料的超高速切削

文章在分析超高速切削加工铝，镁合金薄壁零件，钛合金和镍基合金，纤维强化复合材料的加工规律后给出了加工的工艺规范，并分析了加工效果及经济性。     

难加工材料与振动切削

随着汽车工业、航空航天工业、核工业、兵器工业、电子工业以及现代化机械工业的发展，对产品零部件材料的性能要求也越来越高。有的要在高温、高应力状态下工作；有的要耐腐蚀、耐磨损；有的要能绝缘；有的则需有高导电率。这些材料对于金属切削加工来讲，都是难加工材料。     

难加工材料的切削加工特点和工艺要求

分析难加工材料的切削加工性,针对其切削加工特点,采用相应的机械加工工艺措施。     

切削速度对精密干式车削淬硬工具钢切削力的影响

通过使用PCBN刀具精密干式车削淬硬Cr12MoV工具钢(62±1 HRC)的试验,分析了切削速度对三向切削力的影响,得出了最优切削速度。试验表明:随切削速度提高,三向切削力先急剧增大,后急剧减小,再又缓慢增大。若从最小车削合力与提高加工效率两个角度来优化切削速度,则226 n/min是最优切削速度。试验结果也对精密干式切削淬硬工具钢具有实际指导意义与参考价值。     

Modelling the effects of cutting parameters on residual stresses in hard turning of AISI H11 tool steel

In the present study, an attempt has been made to model the effect of cutting parameters (cutting speed, feed, depth of cut and nose radius) on residual stresses in hard turning of AISI H11 tool steel using ceramic tools. The machining experiments were conducted based on response surface methodology and using the Box–Behnken design of experiments. Residual stresses were determined using the X-ray diffraction technique, and the experimental results were investigated using analysis of variance. The results indicated that the feed and depth of cut are the main influencing factor on residual stresses whereas cutting speed and nose radius are having mild impact on residual stresses. The results show that it is possible to produce tailor-made residual stress levels by controlling the tool geometry and cutting parameters. The aim of this paper is to introduce an original approach for the prediction of residual stresses.     

Determining the effect of cutting parameters on surface roughness in hard turning using the Taguchi method

This study focuses on optimizing turning parameters based on the Taguchi method to minimize surface roughness (Ra and Rz). Experiments have been conducted using the L9 orthogonal array in a CNC turning machine. Dry turning tests are carried out on hardened AISI 4140 (51 HRC) with coated carbide cutting tools. Each experiment is repeated three times and each test uses a new cutting insert to ensure accurate readings of the surface roughness. The statistical methods of signal to noise ratio (SNR) and the analysis of variance (ANOVA) are applied to investigate effects of cutting speed, feed rate and depth of cut on surface roughness. Results of this study indicate that the feed rate has the most significant effect on Ra and Rz. In addition, the effects of two factor interactions of the feed rate-cutting speed and depth of cut-cutting speed appear to be important. The developed model can be used in the metal machining industries in order to determine the optimum cutting parameters for minimum surface roughness.     

On the prediction of surface roughness in the hard turning based on cutting parameters and tool vibrations

This research work concerns the elaboration of a surface roughness model in the case of hard turning by exploiting the response surface methodology (RSM). The main input parameters of this model are the cutting parameters such as cutting speed, feed rate, depth of cut and tool vibration in radial and in main cutting force directions. The machined material tested is the 42CrMo4 hardened steel by Al₂O₃/TiC mixed ceramic cutting tool under different conditions. The model is able to predict surface roughness of Ra and Rt using an experimental data when machining steels. The combined effects of cutting parameters and tool vibration on surface roughness were investigated while employing the analysis of variance (ANOVA). The quadratic model of RSM associated with response optimization technique and composite desirability was used to find optimum values of cutting parameters and tool vibration with respect to announced objectives which are the prediction of surface roughness. The adequacy of the model was verified when plotting the residuals values. The results indicate that the feed rate is the dominant factor affecting the surface roughness, whereas vibrations on both pre-cited directions have a low effect on it. Moreover, a good agreement was observed between the predicted and the experimental surface roughness. Optimal cutting condition and tool vibrations leading to the minimum surface roughness were highlighted.     

带有残余应力的关节轴承外圈硬切削有限元仿真研究

针对关节轴承冷挤压装配后,其轴承外圈存在较大的残余应力的问题,对多次硬切削关节轴承外圈对残余应力的影响和轴承内外圈间隙的分布规律进行了研究,对自润滑关节轴承挤压装配过程和冷却回弹过程进行了仿真分析,开展了多次硬切削带残余应力的GCr15轴承钢关节轴承外圈有限元仿真分析,建立了材料本构模型、损伤初始准则及损伤演化准则之间的关系,提出了热力耦合有限元仿真分析的方法。在Abaqus软件上对多次硬切削对应力分布情况和轴承外圈回弹量等进行了评价分析。研究结果表明,有限元仿真分析能够预测硬切削对自润滑关节轴承外圈残余应力大小的影响和轴承内外圈间隙的变化规律,这对于通过硬切削释放残余应力,控制和提高工件质量具有重要的理论指导意义。     

The influence of local operating features on the cutting parameters in turning

The paper presents an algorithm and a method of correction of cutting speed for turning operations which has been established on the basis of catalogue data. This approach is based on the Taylor equation concerning cutting speed and tool life as well as on the assumption that each technological process is different.     

数控车削中切削参数对表面质量的影响分析

切削参数的选择主要依赖于工艺人员的水平,往往由工艺设计人员凭经验决定,有一定的盲目性。针对数控车削中铝合金的切削参数选择展开研究。首先,针对影响表面质量的几个参数,在CK6136数控车床上加工102铝棒实验工件,得出实验数据,并对实验数据进行分析;其次,对主要参数的交互影响进行研究,结合具体工况,总结出选择方法。     

Pre-evaluation on surface profile in turning process based on cutting parameters

Traditional online or in-process surface profile (quality) evaluation (prediction) needs to integrate cutting parameters and several in-process factors (vibration, machine dynamics, tool wear, etc.) for high accuracy. However, it might result in high measuring cost and complexity, and moreover, the surface profile (quality) evaluation result can only be obtained after machining process. In this paper, an approach for surface profile pre-evaluation (prediction) in turning process using cutting parameters and radial basis function (RBF) neural networks is presented. The aim was to only use three cutting parameters to predict surface profile before machining process for a fast pre-evaluation on surface quality under different cutting parameters. The input parameters of RBF networks are cutting speed, depth of cut, and feed rate. The output parameters are FFT vector of surface profile as prediction (pre-evaluation) result. The RBF networks are trained with adaptive optimal training parameters related to cutting parameters and predict surface profile using the corresponding optimal network topology for each new cutting condition. It was found that a very good performance of surface profile prediction, in terms of agreement with experimental data, can be achieved before machining process with high accuracy, low cost, and high speed. Furthermore, a new group of training and testing data was also used to analyze the influence of tool wear on prediction accuracy.