金属切削中如何选择切削液

概述了切削液的种类和性能,介绍了目前切削液的使用情况,重点探讨了在不同的材料、不同的切削方法、各种常见刀具及良好的经济效益下选择切削液的基本原则.     

Cutting tool damage in interrupted cutting

The shaping and turning of a workpiece with key ways, milling and the high speed turning of small workpieces, in which the risk of tool chipping and breakage decreases in the order given, exhibit three danger areas: tool entry, tool exit and cyclic heating and cooling. The relative importance of these depends on the dimensions of the cut, the cutting speed, the heating time/cooling time, the workpiece and tool materials, the shape of the tool and the geometry of the entry and exit. A better understanding of the phenomena occurring during tool entry is required, and therefore the cutting forces during entry and exit have been studied. The chipping caused by the exit phenomena has been explained using the results of a finite element study of the workpiece and the tool. The effect of rounding or chamfering the edges of carbide cutting tools for interrupted cutting, e.g. milling, is discussed and the work required before this can be optimized is outlined.     

金属切削加工性能浅析

阐述了金属切削加工的基本过程及特征，讨论了金属切削加工性的衡量标准及影响茵素，进而探讨了改善金属切削加工性的措施。     

超声处理乳化液在金属切削中的应用

为了减少机械加工中乳化液的使用量,达到节能减排的目的,对乳化液进行了超声波处理,并用它做切削液进行了正交切削试验,研究了乳化液流量、处理时间、水质、乳化液浓度等参数对主切削力的影响,给出了正交试验优化后的各因素取值为:流量2.0L/min,处理时间1.5h/L,水质用自来水,浓度10%.     

数控管切割机床相贯线切割的研究

为了满足数控切割管材的需要,构建了一种计算相贯线和坡口的数学模型.该模型首先在同个坐标系中建立圆柱管数学方程,计算出切管内相贯线上点的坐标数据,然后根据坡口角度,计算出数控机床割咀摆动角度,引导数控切割机床正确进行相贯线和坡口一次成型的切割.通过应用实例,验证了该数学模型的可行性和有效性,研究成果已应用于五轴数控火焰切割机床数控系统的开发中.     

德马吉中国推出“绿灯”预检计划

<正>作为全球领先的切削机床制造商,德马吉致力于向中国的用户提供技术领先的数控机床的同时,更为用户提供富有本地化特色的技术解决方案与全面服务。如今,德马吉提供的服务已包含有备品备     

粉末冶金零件的切削加工

<正>粉末冶金是一种以金属粉末(包括有非金属粉末混入状况)为原料,用于烧结成形,制造金属摩擦材料和制品的工艺技术。粉末冶金生产的材料、零件具有质优、价廉、节能和省材等特点,被广泛应用于汽     

Friction modelling in metal cutting

This paper reviews the experimental evidence for what is the nature of the friction contact between chip and tool during continuous chip formation and the historical development of friction models. It considers three separate circumstances of turning: at low speeds when lubricants can reduce friction by partial penetration of the chip-tool contact; at high speeds when thermal softening can provide self-lubrication; and at intermediate speeds when in some cases solid-lubricating inclusions from the work material can segregate in the chip-tool contact. It demonstrates, through numerical simulation of the turning process, shortcomings in a commonly used friction model and proposes an improved formulation.     

Chip curling in metal cutting

Chip curling in metal cutting is considered. A method is proposed for determining the dimensions of the dead zone at the cutter tip on the basis of the chip’s geometric parameters.     

乳化型深孔切削液的切削试验与分析

对切削液的类型和功能进行阐述,比较几种切削液的功能和切削特点,根据内排屑深孔加工的特点和对切削液的要求,选择几种乳化型切削液进行钻削试验。通过对比试验及结果分析,确定出能适应深孔钻削加工的乳化型切削液,可以满足深孔钻削加工中对刀具的冷却润滑和排屑效果,从而可以减少对切削油的使用,降低生产成本及对环境的污染。     

干切削加工刀具及其设计

适宜的刀具材料和刀具几何参数是干切削加工的关键条件之一.在分析干切削加工对刀具要求的基础上,阐述了干切削刀具设计的要点,并结合应用实例说明了刀具设计对干切削加工的重要性.     

Elementary chip formation in metal cutting

Elementary-chip formation in the machining of hard materials is considered. Formulas are presented for the geometric parameters of the elementary chip as a function of the machining conditions.     

Temperature measurement in orthogonal metal cutting

Orthogonal cutting experiments were carried out on steel at different feedrates and cutting speeds. During these experiments the chip temperatures were measured using an infrared camera. The applied technique allows us to determine the chip temperature distribution at the free side of the chip. From this distribution the shear plane temperature at the top of the chip as well as the uniform chip temperature can be found. A finite-difference model was developed to compute the interfacial temperature between chip and tool, using the temperature distribution measured at the top of the chip.Nomenclature contact length with sticking friction behaviour [m] - c specific heat [J kg^–1 K^–1] - contact length with sliding friction behaviour [m] - F _P feed force [N] - F _V main cutting force [N] - h undeformed chip thickness [m] - h _c deformed chip thickness [m] - i,j denote nodal position - k thermal conductivity [W m^–2 K^–1] - L chip-tool contact length [m] - p defines time—space grid, Eq. (11) [s m^–2] - Q _C heat rate entering chip per unit width due to friction at the rake face [W m^–1] - Q _T total heat rate due to friction at the rake face [W m^–1] - Q _% percentage of the friction energy that enters the chip - q ₀ peak value ofq(x) [W m^–2] - q _e heat rate by radiation [W] - q(x) heat flux entering chip [W m^–2] - t time [s] - T temperature [K] - T _C uniform chip temperature [°C] - T _max maximum chip—tool temperature [°C] - T _mean mean chip—tool temperature [°C] - T _S measured shear plane temperature [°C] - x,y Cartesian coordinates [m] - V cutting speed [m s^–1] - V _C chip speed [m/s] - rake angle - ,, control volume lumped thermal diffusivity [m² s^–1] - emmittance for radiation - exponent, Eq. (3) - density [kg m^–3] - Stefan-Boltzmann constant [W m^–2 K⁴] - (x) shear stress distribution [N m^–2] - shear angle     

Acoustic emission during orthogonal metal cutting

The theory of acoustic emission and the analysis of emission signals is reviewed as it applies to generation of acoustic emission in metal cutting. Based upon the mechanics of the orthogonal cutting operation a relationship is developed between the root mean square (RMS) voltage of the acoustic emission and fundamental cutting parameters. The validity of this relationship is evaluated by a series of tests varying cutting speed, feed and rake angle for orthogonal machining. Strong dependence of the RMS voltage of the emission on both strain rate and cutting velocity was observed. The sources of acoustic emission in metal cutting are discussed and areas of additional work in the study of acoustic emission from metal cutting are identified.