Sun-cut超级螺旋立铣刀

本刀具(见照片)是加工难铣削材料的专用立铣刀。这种立铣刀是在原来的整体立铣刀的基础上,加以改进,使之设计成60°的螺旋角形状,以减轻切削抗力。因而,可以提高用普通硬质合金立铣刀、高速钢立铣刀难于奏效的工具钢(HRC30以下)、不锈钢、碳钢及耐热钢等难加工材料的铣削效率,并能提高加工精度。特点1.本刀具采用硬度高、韧性好的超细微粒合金BRM20制造,几何形状见附图,螺旋角为60°。应用这种刀具对难加工的不锈钢材料作了实际切削试验,结果其寿命要比高速钢立铣刀提高10倍以上,比原来的硬质合金立铣刀提高2.5倍以上,效率也高1.4～3.7倍。     

氮化硅铣刀角度对镍基高温合金切削力的影响

GH4169镍基高温合金属于难加工材料,为模拟其粗铣加工过程的切削力,在UG软件中建立不同前角、后角以及螺旋角的平头立铣刀模型,选择合适的铣削参数,采用正交试验法在ABAQUS软件中对氮化硅陶瓷铣刀铣削GH4169镍基高温合金过程进行仿真,探讨了铣刀几何角度对铣削力的影响规律,并获得了适合粗铣加工的铣刀角度组合。结果表明,螺旋角对铣削力影响较大,进给抗力随铣刀径向前角增大而减小。     

金属陶瓷螺旋立铣刀槽型优选及应用研究

通过NAK80模具钢的铣削试验,运用全面试验方法研究金属陶瓷螺旋立铣刀螺旋角和径向前角对切削性能的影响,优化了其结构参数,对比研究了涂层和非涂层金属陶瓷立铣刀切削性能、涂层金属陶瓷立铣刀在气冷和水冷条件下切削性能。利用扫描电镜(SEM)、X射线能谱仪(EDS)对主切削刃进行观察,研究了两种刀片的磨损形态及磨损机理。试验结果表明:优选金属陶瓷螺旋立铣刀螺旋角为45°,径向前角为0°;非涂层金属陶瓷螺旋立铣刀不适合加工P类材料,Al Ti N涂层金属陶瓷螺旋立铣刀加工P类材料时磨损形式为粘结磨损和化学磨损;气冷有利于减小刀具磨损,延长刀具寿命;水冷有利于提高零件表面质量,表面粗糙度值可稳定在Ra0. 05以下,但因热冲击作用,其金属陶瓷基体易出现热裂纹,导致出现刀具微崩和涂层不规则脱落现象。     

立铣刀的螺旋角

<正> 选择恰当的螺旋角,对于充分发挥立铣刀的切削性能是很重要的。本文拟着重谈谈立铣刀螺旋角的有关问题。1、螺旋角与切削力用立铣刀切削工件时,刀具螺旋角的大小对加工精度和刀具寿命有着很大的影响。笔者曾将直径14毫米、材料为SKH56的双齿立铣刀,分别作成螺旋角为0°、10°、20°、30°、40°、50°的六种立铣刀,选用S50C(HB 170)     

基于SolidWorks的刀具螺旋槽的模拟加工分析

1.刀具螺旋槽的加工形成机理 金属切削刀具产品中,带有螺旋槽的刀具很普遍。如：麻花钻头、螺旋槽立铣刀、螺旋槽丝锥、可转位螺旋立铣刀等,刀具螺旋槽除热轧及扭制等无屑加工形成以外,绝大多数情况下是靠铣削形成的。如图1所示,β为螺旋角,λ为螺旋升角,D为工件直径,L为导程,L=πD/tanβ。     

波形刃铣刀成型砂轮设计

波形刃立铣刀一般使用成型砂轮进行磨削,受刀具螺旋角、后角的影响,在磨削过程中砂轮会产生干涉。通过对干涉原因进行分析,提出了对成型砂轮的修正方法。实践表明修正后的砂轮能够加工出合格的刀具。     

[刀具及切削工艺]高速铣削中TaC（NbC）对硬质合金刀具磨损性能的影响

针对航空航天钛合金加工时硬质合金刀具磨损过快的难题,制备了主元素一致、微量合金碳化物TaC（NbC）含量不同的两种WC-Co基硬质合金材料。采用高温维氏硬度计检测两种材料的高温硬度和高温断裂韧性,并制备相同几何参数的立铣刀对钛合金TC4进行铣削加工试验。试验结果表明：在硬质合金中添加微量合金碳化物TaC（NbC）,可以同时提高材料的高温硬度和高温断裂韧性,在相同的切削条件下,添加微量合金碳化物TaC（NbC）的硬质合金立铣刀比未添加微量合金碳化物的立铣刀耐磨性更好,刃口断裂裂纹更少,刀具使用寿命更长,更适合航空航天钛合金材料的高速铣削加工。     

等螺旋角锥度立铣刀

等螺旋角锥度立铣刀,是一种较为理想的优质高效的刀具。但由于其螺旋槽的加工困难,所以,它的发展很慢。我们厂十多年来一直在使用着等导程锥度立铣刀,对于等螺旋角锥度立铣刀,自1969年以来亦曾作过多次设想和试制。1974年九月,我们使用普通万能铣床,加工制做了为数不多的零件,顺利地制出了第一批等螺旋角锥度立铣刀     

等螺旋角锥度立铣刀

等螺旋角锥度立铣刀,是一种较为理想的比质高效的刀具。但由于其螺旋槽的加工困难,所以,它的发展很慢。我们厂十多年来一直在使用着等导程锥度立铣刀,对于等螺旋角锥度立铣刀,自1969年以来亦曾作过多次设想和试制。1974年九月,我们使用普通万能铣床,加工制做了为数不多的零件,顺利地制出了第一批等螺旋角锥度立铣刀     

高速铣削中TaC(NbC)对硬质合金刀具磨损性能的影响

针对航空航天钛合金加工时硬质合金刀具磨损过快的难题,制备了主元素一致、微量合金碳化物TaC(NbC)含量不同的两种WC-Co基硬质合金材料。采用高温维氏硬度计检测两种材料的高温硬度和高温断裂韧性,并制备相同几何参数的立铣刀对钛合金TC4进行铣削加工试验。试验结果表明:在硬质合金中添加微量合金碳化物TaC(NbC),可以同时提高材料的高温硬度和高温断裂韧性,在相同的切削条件下,添加微量合金碳化物TaC(NbC)的硬质合金立铣刀比未添加微量合金碳化物的立铣刀耐磨性更好,刃口断裂裂纹更少,刀具使用寿命更长,更适合航空航天钛合金材料的高速铣削加工。     

Simulation-based solid carbide end mill design and geometry optimization

Designing a high-performance solid carbide end mill is difficult due to the complex relationship between end mill geometry and numerous or conflicting design goals. Earlier approaches of computer-aided solid end mill design are limited to only a few design aspects. This article presents a three-dimensional finite element method of milling process for solid carbide end mill design and optimization. The software was secondarily developed based on UG platform, integrating the parametric design with the development of the two-dimension drawing of solid carbide end mill. The three-dimension finite element simulation for milling Ti-6Al-4V alloy was performed and the geometrical parameters were optimized based on the objective of low cutting force and cutting temperature. As a result, a simulation-based design and optimization of geometrical parameters of tool structure and cutting edge is possible. The optimized results, for the geometrical parameters of tool structure and cutting edge when milling titanium alloy using a 20-mm diameter solid carbide end mill, is a 12-mm diameter of inner circle, four flutes, a 45 ° helix angle, and a 9 ° rake angle of the side cutting edge.     

Stability of milling with non-uniform pitch and variable helix Tools

We study mechanical vibrations in milling with non-uniform pitch and variable helix tools. The process is modeled by a periodic delay differential equation with distributed delay, which takes into account, for example, the nonlinear cutting force behavior, the effect of runout, and the exact delay distribution due to the unequally spaced flutes. We present a new method for the identification of the chatter stability lobes from the linearized system that is based on the multifrequency solution. We give detailed remarks on the truncation of the resulting infinite dimensional matrices and the efficient numerical implementation of the method. Cutting tests for steel milling with a customary end mill with non-uniform pitch and variable helix angle and a conventional end mill with uniform pitch and constant helix angle are performed. The numerical and experimental results coincide well. They reveal a significant increase of the limiting depth of cut for the variable helix tool compared to the conventional tool. Moreover, we show that in contrast to conventional tools, for non-uniform pitch and variable helix tools, an exact model with time-varying coefficients, nonlinear cutting force behavior, and runout is necessary for an accurate prediction of the stability lobes.     

TC4钛合金铣削刀具C形刃几何参数优化实验研究

通过对TC4钛合金进行侧铣加工,采用正交设计方法研究了硬质合金立铣刀侧刃几何参数对切削力和表面粗糙度的影响,用极差法分析了刀具几何参数对铣削力的影响;并以最小表面粗糙度为目标,采用田口法对刀具几何参数进行了优选。结果表明:螺旋角对铣削力的影响最大,对F_x、F_z,C形刃宽度影响次之,C形刃角度的影响最小;对于F_y,C形刃角度次之,C形刃宽度的影响最小;当螺旋角为25°、C形刃宽度为0.2mm、角度为-25°时可获得最小表面粗糙度。     

Prediction of vibration amplitude from machining parameters by response surface methodology in end milling

Decreasing vibration amplitude during end milling process reduces tool wear and improves surface finish. Mathematical model has been developed to predict the acceleration amplitude of vibration in terms of machining parameters such as helix angle of cutting tool, spindle speed, feed rate, and axial and radial depth of cut. Central composite rotatable second-order response surface methodology was employed to create a mathematical model, and the adequacy of the model was verified using analysis of variance. The experiments were conducted on aluminum Al 6063 by high-speed steel end mill cutter, and acceleration amplitude was measured using FFT analyzer. The direct and interaction effect of the machining parameter with vibration amplitude were analyzed, which helped to select process parameter in order to reduce vibration, which ensures quality of milling.     

Theoretical modelling of cutting forces in helical end milling with cutter runout

A theoretical cutting force model for helical end milling with cutter runout is developed using a predictive machining theory, which predicts cutting forces from the input data of workpiece material properties, tool geometry and cutting conditions. In the model, a helical end milling cutter is discretized into a number of slices along the cutter axis to account for the helix angle effect. The cutting action for a tooth segment in the first slice is modelled as oblique cutting with end cutting edge effect and tool nose radius effect, whereas the cutting actions of other slices are modelled as oblique cutting without end cutting edge effect and tool nose radius effect. The influence of cutter runout on chip load is considered based on the true tooth trajectories. The total cutting force is the sum of the forces at all the cutting slices of the cutter. The model is verified with experimental milling tests.     

The optimal design of micro end mill for milling SKD61 tool steel

Micromachining has become a necessary manufacturing method. Developing and applying micro-milling are determined according to the increasingly influential progress of micro tool designs and the evolution of machine tool technologies. This study employed a tungsten carbide micro end mill with a diameter of 200 μm for the design model of the micro-milling SKD61 tool steel by the finite element method. This study first used the effective rake angle on an oblique cutting process to simplify the complicated geometric relationship of the micro end mill into the orthogonal cutting model. Simulation analysis will be conducted by using the four parameters of effective rake angle, relief angle, cutting velocity, and cutting depth designed according to the Taguchi orthogonal array. This study then evaluated the four micro-milling characteristics of cutting force, tool maximum temperature, distance between the tool maximal temperature point and the tool tip point, and tool–chip contact length. The results of ANOVA show that the most influential simulation parameter on micro-milling is effective rake angle, followed by cutting velocity, cutting depth, and relief angle. The empirical results indicate that the proposed method can serve as a design base for developing and applying the micro end mill.     

Effect of tool stiffness upon tool wear in high spindle speed milling using small ball end mill

Longer tool life can be tentatively achieved at a higher feed rate using a small ball end mill in high spindle speed milling (over several tens of thousands of revolutions per minute), although the mechanism by which tool life is improved has not yet been clarified. In the present paper, the mechanism of tool wear is investigated with respect to the deviation in cutting force and the deflection of a ball end mill with two cutting edges. The vector loci of the cutting forces are shown to correlate strongly with wear on both cutting edges of ball end mills having various tool stiffnesses related to the tool length. The results clarified that tool life can be prolonged by reducing tool stiffness, because the cutting forces are balanced, resulting in even tool wear on both cutting edges as tool stiffness is lowered to almost the breakage limit of the end mill. A ball end mill with an optimal tool length showed significant improvement in tool life in the milling of forging die models.     

斜圆柱结构的新型微细球端铣刀的设计与制造

针对微细切削刀具的特点与应用需求,设计一种斜圆柱结构的新型微细球端铣刀,将铣刀球端刀刃复杂的空间曲线转化为易加工的平面曲线。根据所设计铣刀的几何结构特征,从制造工艺方面进行刀具结构的调整,分析刀具的刃磨成形原理,并在微细刀具数控刃磨机上完成该刀具的制作。通过与传统螺旋槽球端铣刀和椭圆柱刃型球端铣刀的切削性能对比试验,研究所设计刀具的切削性能。试验结果表明,所设计的微细球端立铣刀在显著降低刀具制备难度的同时,具有较高的切削刃强度,能够满足硬脆性材料的微细切削要求。     

Development of an automatic arc welding system using SMAW process

In end milling of pockets, variable radial depth of cut is generally encountered as the end mill enters and exits the corner, which has a significant influence on the cutting forces and further affects the contour accuracy of the milled pockets. This paper proposes an approach for predicting the cutting forces in end milling of pockets. A mathematical model is presented to describe the geometric relationship between an end mill and the corner profile. The milling process of corners is discretized into a series of steady-state cutting processes, each with different radial depth of cut determined by the instantaneous position of the end mill relative to the workpiece. For the cutting force prediction, an analytical model of cutting forces for the steady-state machining conditions is introduced for each segmented process with given radial depth of cut. The predicted cutting forces can be calculated in terms of tool/workpiece geometry, cutting parameters and workpiece material properties, as well as the relative position of the tool to workpiece. Experiments of pocket milling are conducted for the verification of the proposed method.