共查询到19条相似文献,搜索用时 171 毫秒
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为了研究钛合金Ti6Al4V切削过程中的切削力特性,采用硬质合金涂层和无涂层刀具进行了外圆干车削试验,提取切削力信号,通过研究切削力的静动态特性,揭示了切削力与切削速度、刀具材料、刀具磨损以及切屑形成的关系.结果表明:钛合金切削过程中,切削力的静态分量中径向力Fp最大,直接导致刀具后刀面磨损;随着切削速度的变化,切削力的变化是由刀具磨损、材料本身的特性等多方面因素综合作用的结果,切削力动态分量分形维数可用于刀具状态监控;锯齿形切屑的产生与切削力的高频变化有直接的关系,锯齿生成频率可以作为切削力动态分量频率的一个表征,选取适当的切削参数可以降低由于锯齿屑产生引起的切削力振动. 相似文献
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508Ⅲ钢材料应用于核岛AP1000蒸发器水室封头中,是一种高强度、高硬度和高断面收缩率的低碳合金钢。硬质合金刀具在切削508Ⅲ钢时,会产生较大的切削力以及切削振动,从而影响刀具使用寿命。本文进行硬质合金刀具铣削508Ⅲ钢试验,探究切削力以及切削振动信号对刀具磨损敏感性的变化趋势的影响,并运用互相关函数分析切削力以及切削振动信号对硬质合金刀具磨损形态的敏感程度。试验结果表明:切削力较切削振动相比,对刀具磨损形态的影响较大,并在切削速度为298m/min时,切削力、切削振动对刀具磨损形态互相关程度较高。为进一步研究通过切削力等信号检测刀具磨损状态提供试验及理论参考。 相似文献
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不同铝基体SiC_p/Al复合材料切削力与刀具的磨损研究 总被引:1,自引:0,他引:1
对不同增强相体分比、颗粒尺寸和基体材料的Si CP/Al复合材料进行切削试验,分析了铝基体材料和颗粒尺寸对高、低增强相体分比Si C_p/Al复合材料切削力的影响。针对Si C_p/Al复合材料切削力的复杂性,提出用分形维数的方法定量描述切削力波动的复杂程度。对不同铝基体Si C_p/Al复合材料进行刀具磨损试验,研究铝基体对刀具磨损的影响。结果表明:随着增强相体分比和颗粒尺寸的增加,铝基体对切削力的影响减弱;随着增强相体分比增加,颗粒尺寸对于切削力影响有增大趋势;分形维数可以定量描述切削力波动性质,且Si C_p/6063Al切削力波动频率高于Si C_p/2024Al;相对于Si C_p/2024Al,切削Si C_p/6063Al时刀具前刀面粘结磨损加剧而颗粒磨损减少,刀具后刀面磨损程度相对较高。 相似文献
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金属加工过程中,切削刀具的状态对于生产效率和表面加工质量有重要影响,因此刀具磨损监测具有重要意义。刀具磨损监测是柔性制造系统研究工程的一个重要课题。切削力信号作为加工过程中最稳定和最可靠的信号,和刀具磨损密切相关。从实验上分析切削力与刀具磨损的相关性,提出刀具切削力变化与磨损变化是一致的。基于有限元分析软件对车削加工进行仿真研究,模拟了切削力的大小分布,并将模拟结果与实验结果进行了比较分析,为实际工艺参数的选择提供了理论指导。 相似文献
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为分析碳纤维增强树脂基复合材料(CFRP)/钛合金(TC4)叠层材料低频振动制孔工艺下刀具磨损状态,开展基于切削力信号的制孔刀具磨损状态研究.通过采集CFRP/TC4叠层材料低频振动制孔过程中的切削力信号,进行时域和频域分析,探讨各信号特征量与刀具磨损状态之间的联系.研究结果表明:CFRP/TC4叠层材料低频振动制孔轴... 相似文献
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在试验研究基础上进行了有后刀面磨损的正交切削模型分析。经过正交切削试验及理论分析,发现后刀面磨损无论是定性上还是定量上都不影响刀具基本切削或剪切过程,即不改变剪切角和摩擦角,但是在磨损区的摩擦力及整个切削力都会增加。充分利用剪切区分析理论,确定了剪切区的切削力、后刀面磨擦力和后刀面磨损量的对应关系,从而建立了在后刀面磨损情况下的切削力模型。 相似文献
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以直刃尖刀超声辅助切割Nomex蜂窝芯的简化模型为基础,建立基于脆性断裂力学理论的超声辅助切削动态力模型,并分情况讨论了刀具与材料间的相对运动关系。分析指出在不同振幅条件下,材料的切割破坏存在断续和连续两种形式,进而推导了切割过程中的切削力的理论公式。其中超声振幅、刀具前倾角、进给速度和超声频率等参数对材料切削力大小均有影响。在理论分析的基础上,开展了超声辅助切割Nomex蜂窝芯复合材料实验。试验结果表明,进给方向的超声振幅和刀具前倾角对切削力的影响较大:当进给方向的超声振幅从0到15 μm变化、刀具前倾角从15°到45°变化时,切削力均可降低70%~80%;进给速度和超声频率对于切削力影响较小:当进给速度从500到6000 mm/min变化12倍时,切削力仅变为1.5倍;超声频率35 kHz与15 kHz相比,切削力降低10%~30%。试验结果与理论分析结论一致。 相似文献
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The effects of chip load, tool wear, and tool eccentricity on milling force are similar; in order to distinguish them from each other, the spectral characteristics of milling force for four flute end mills was studied. With simplified milling force model, the calculation expression of instantaneous milling force under tool eccentricity was derived based on the 2D geometry of tool cutting into workpiece. Using simulation methods, the amplitude spectra of milling forces under neither wear nor eccentricity, only eccentricity, both wear and eccentricity, and the every phase spectrum of force caused only by wear of one tooth were analyzed. The analysis results showed that the basic and third harmonic amplitudes of spindle frequency were linear only with eccentric distance, the fourth harmonic amplitude was linear only with feed, the second harmonic component was in relationship only with tool wear, and harmonics with same frequency caused by wear of different teeth were in phase or out of phase. Then corresponding milling experiments were done, the relations between experimental harmonic amplitudes of force and milling parameters were analyzed, and were found being in good agreement with above simulation results. These indicate that amplitudes of these harmonics could be taken as indices in recognizing eccentricity, wear, and chip load, respectively, and their variations contain in-process information of tool wear. This study proposes a new idea of identifying tool eccentricity and wear with force itself. 相似文献
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In this study, a new slip-line field model and its associated hodograph for orthogonal cutting with a rounded-edge worn cutting tool are developed using Dewhurst and Collins's matrix technique. The new model considers the existence of dead metal zone in front of the rounded-edge worn cutting tool. The ploughing force and friction force occurred due to flank wear land, chip up-curl radius, chip thickness, primary shear zone thickness and length of bottom side of the dead metal zone are obtained by solving the model depending on the experimental resultant force data. The effects of flank wear rate, cutting edge radius, uncut chip thickness, cutting speed and rake angle on these outputs are specified. 相似文献
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This paper describes the micro cutting of wear resistant tungsten carbides using PCD (Poly-Crystalline Diamond) cutting tools
in performance with SEM (Scanning Electron Microscope) direct observation method. Turning experiments were also carried out
on this alloy (V50) using a PCD cutting tool. One of the purposes of this study is to describe clearly the cutting mechanism
of tungsten carbides and the behavior of WC particles in the deformation zone in orthogonal micro cutting. Other purposes
are to achieve a systematic understanding of machining characteristics and the effects of machining parameters on cutting
force, machined surface and tool wear rates by the outer turning of this alloy carried out using the PCD cutting tool during
these various cutting conditions. A summary of the results are as follows : (1) From the SEM direct observation in cutting
the tungsten carbide, WC particles are broken and come into contact with the tool edge directly. This causes tool wear in
which portions scrape the tool in a strong manner. (2) There are two chip formation types. One is where the shear angle is
comparatively small and the crack of the shear plane becomes wide. The other is a type where the shear angle is above 45 degrees
and the crack of the shear plane does not widen. These differences are caused by the stress condition which gives rise to
the friction at the shear plane. (3) The thrust cutting forces tend to increase more rapidly than the principal forces, as
the depth of cut and the cutting speed are increased preferably in the orthogonal micro cutting. (4) The tool wear on the
flank face was larger than that on the rake face in the orthogonal micro cutting. (5) Three components of cutting force in
the conventional turning experiments were different in balance from ordinary cutting such as the cutting of steel or cast
iron. Those expressed a large value of thrust force, principal force, and feed force. (6) From the viewpoint of high efficient
cutting found within this research, a proper cutting speed was 15 m/min and a proper feed rate was 0.1 mm/rev. In this case,
it was found that the tool life of a PCD tool was limited to a distance of approximately 230 m. (7) When the depth of cut
was 0.1 mm, there was no influence of the feed rate on the feed force. The feed force tended to decrease, as the cutting distance
was long, because the tool was worn and the tool edge retreated. (8) The main tool wear of a PCD tool in this research was
due to the flank wear within the maximum value of Vmax being about 260 μ. 相似文献
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Ning Fang P. Srinivasa Pai S. Mosquea 《The International Journal of Advanced Manufacturing Technology》2011,52(1-4):65-77
High-speed machining has been receiving growing attention and wide applications in modern manufacture. Extensive research has been conducted in the past on tool flank wear and crater wear in high-speed machining (such as milling, turning, and drilling). However, little study was performed on the tool edge wear??the wear of a tool cutting edge before it is fully worn away??that can result in early tool failure and deteriorated machined surface quality. The present study aims to fill this important research gap by investigating the effect of tool edge wear on the cutting forces and vibrations in 3D high-speed finish turning of nickel-based superalloy Inconel 718. A carefully designed set of turning experiments were performed with tool inserts that have different tool edge radii ranging from 2 to 62???m. The experimental results reveal that the tool edge profile dynamically changes across each point on the tool cutting edge in 3D high-speed turning. Tool edge wear increases as the tool edge radius increases. As tool edge wear dynamically develops during the cutting process, all the three components of the cutting forces (i.e., the cutting force, the feed force, and the passive force) increase. The cutting vibrations that accompany with dynamic tool edge wear were analyzed using both the traditional fast Fourier transform (FFT) technique and the modern discrete wavelet transform technique. The results show that, compared to the FFT, the discrete wavelet transform is more effective and advantageous in revealing the variation of the cutting vibrations across a wide range of frequency bands. The discrete wavelet transform also reveals that the vibration amplitude increases as the tool edge wear increases. The average energy of wavelet coefficients calculated from the cutting vibration signals can be employed to evaluate tool edge wear in turning with tool inserts that have different tool edge radii. 相似文献
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