共查询到20条相似文献,搜索用时 46 毫秒
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针对介观尺度切削加工中存在的最小切削厚度,描述了最小切削厚度形成机理,提出了一种基于刀具刃口半径及工件和刀具间摩擦因数的最小切削厚度理论模型,并将切削参数代入理论模型计算出其最小切削厚度值为2.3μm。以钛合金Ti6Al4V为研究对象,基于Abaqus建立钛合金二维切削模型,通过仿真得出最小切削厚度值在2μm~3μm之间,从而验证了最小切削厚度理论模型的正确性。并分析了刀具刃口半径及工件与刀具间摩擦因数对最小切削厚度的影响,结果表明,最小切削厚度值与刀具刃口半径成正比,与工件和刀具间摩擦因数成反比。 相似文献
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针对微细切削加工中存在的尺度效应,研究了微细切削加工中尺度效应产生的机理,通过建立微细切削加工有限元模型,模拟并分析了微细切削加工过程的尺度效应,揭示了切削刃钝圆半径引起尺度效应的内在作用机理。 相似文献
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张翔潘旭东王广林 《计算机集成制造系统》2018,(12):2933-2940
为提高钛合金介观尺度铣削加工表面质量,以主轴转速、每齿进给量、轴向切削深度为主要研究因素,对介观尺度铣削表面粗糙度特征进行了分析,优化了工艺参数。考虑到介观尺度铣削加工的间断性切屑形成和单齿切削现象,分析了刀具转角与切削厚度及累计弹塑性变形次数的对应关系。在此基础上,设计了正交实验,将铣削表面划分为逆铣区域、中间区域和顺铣区域,通过方差分析确认每齿进给量是介观尺度铣削表面粗糙度最重要的影响因素。采用田口方法分别对局部区域加工工艺参数进行优化。实验结果表明,相对于中间区域,逆铣区域和顺铣区域弹塑性变形更频繁,表面粗糙度更高,以逆铣区域或顺铣区域表面粗糙度为优化目标时的优化效果更好。 相似文献
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介观尺度心轴的表面粗糙度预测模型建立及参数优化 总被引:1,自引:0,他引:1
为控制惯性约束聚变靶制备中介观尺度心轴的表面粗糙度,提出一种应用旋转设计技术安排试验的方法,通过非线性回归分析,建立基于进给量、背吃刀量、主轴转速和刀尖角四个主要切削参数的介观尺度心轴的表面粗糙度二次预测模型。分析结果表明,该模型的拟合值能较好地反映心轴车削表面粗糙度,并且具有比理论表面粗糙度计算值更高的精度。在主要切削参数中,进给量和刀尖角比背吃刀量和主轴转速对心轴表面粗糙度的影响更显著。利用优化得到的最佳表面粗糙度为目标切削条件,选用直线切削刃超细晶粒硬质合金刀具,在φ0.6 mm的心轴上得到Ra16.53 nm的表面粗糙度。 相似文献
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介观尺度微型铣床开发及性能试验 总被引:1,自引:0,他引:1
针对微机电系统(Microeletro mechanical system, MEMS)技术和超精密加工技术局限,开展面向介观尺度微细铣削技术的研究。首先根据介观尺度铣削的加工特点,对其机理研究的关键问题进行详细的分析和讨论,提出微细铣削理论的研究重点及研究方法。然后在分析微细铣削成形条件和加工要求的基础上,开发微型铣床系统,并对系统各组成子系统及性能指标进行描述。最后开展机床加工性能评估试验,通过精度测量、误差分析和误差补偿提高工作台的定位精度达到1.62 μm,采用直径0.127 mm铣刀开展微铣削试验,通过表面粗糙度测量和同心圆切削试验评估机床的加工精度,在此基础上通过复杂零件加工实例进一步说明机床的加工能力,论证小型化机床加工技术的可行性和实用性。 相似文献
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20世纪科学技术的高速发展,促使人们将科学视角一方面转向宇观世界的更深处,渴望藉此揭示宇宙起源之谜;另一方面,人们又把触角伸向微观物质世界的细微处,期望获得更细致、更精确的新知识体系。日本东京科学大学谷口纪男教授于 1974年提出了纳米技术 (nanotechnology)的概念。即随着精密加工技术的发展,精度要求的提高,加工精度达 1nm数量级的要求已提上日程。由于固体可确定的长度或可分辨的极限是原子之间或原子晶格之间的距离,即约为 0.3nm,因此, 1nm精度的加工所相应的最小去除尺寸单位必定是 1个原子尺寸,由此揭开了微 /纳米… 相似文献
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The texture of diamond-machined optical-quality surfaces on polycrystalline metals is strongly influenced by the anisotropic elastic and plastic properties of the work material. Plunge-cut experiments were carried out on coarse-grained OFHC copper specimens to examine the correlations between surface topography, process forces, and the orientation of individual grains. Three distinct surface microtopographies were found on individual grains regardless of cutting speed and tool radius. These microtopographies are closely linked with different cutting force levels, which also appear to influence burr formation in the cutting process. The crystallographic orientations of individual grains, which reveal different microtopographies after machining, were determined by X-ray diffraction to correlate the generated surface texture with the material properties. 相似文献
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Abstract The texture of diamond-machined optical-quality surfaces on polycrystalline metals is strongly influenced by the anisotropic elastic and plastic properties of the work material. Plunge-cut experiments were carried out on coarse-grained OFHC copper specimens to examine the correlations between surface topography, process forces, and the orientation of individual grains. Three distinct surface microtopographies were found on individual grains regardless of cutting speed and tool radius. These microtopographies are closely linked with different cutting force levels, which also appear to influence burr formation in the cutting process. The crystallographic orientations of individual grains, which reveal different microtopographies after machining, were determined by X-ray diffraction to correlate the generated surface texture with the material properties. 相似文献
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2D-FEM SIMULATION OF THE ORTHOGONAL HIGH SPEED CUTTING PROCESS 总被引:6,自引:0,他引:6
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M. Weber H. Autenrieth J. Kotschenreuther P. Gumbsch V. Schulze D. Löhe 《Machining Science and Technology》2013,17(4):474-497
For the production of small quantities of micro devices, machining is a low cost alternative to lithographic processing techniques. However, machining shows process specific size-effects upon miniaturization to the micrometer regime. Hence, the orthogonal turning process is chosen to study the influence of process parameters like uncut chip thickness h, cutting velocity vc and cutting edge radius rβ on the cutting force and the surface plastification by two-dimensional, thermo-mechanically coupled finite element simulations. A rate-dependent plasticity law is used for investigation of a normalized medium carbon steel (AISI 1045). Furthermore, the characteristics of the influences of the different parameters are analyzed mathematically by similarity mechanics. In particular, the frictional effects on the cutting process are studied in detail using a friction coefficient μ based on experimental results, and the influences of the process parameters on the cutting force and the plastic deformation of the surface layer are determined numerically. These results are compared with experimental measurements. The specific cutting forces are analyzed and discussed in detail. Size-effects observed experimentally are also found by numerical simulations. 相似文献
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SIMULATION OF CHIP FORMATION IN ORTHOGONAL METAL CUTTING PROCESS: AN ALE FINITE ELEMENT APPROACH 总被引:1,自引:0,他引:1
Lagrangian and Eulerian finite element formulations have been traditionally used for modeling of the orthogonal metal cutting process. In this paper it is shown that a more general formulation, the arbitrary Lagrangian-Eulerian method (ALE), may be used to combine the advantages and avoid the drawbacks of both methods in a single analysis. Due to the characteristics of the cutting process, ALE formulation offers a very efficient modeling approach for the cutting process. A comprehensive ALE model along with strain rate and temperature dependent constitutive equations and a contact/friction algorithm is used to analyze the thermo-elasto-plastic process of plane strain orthogonal cutting. Simulation results for cutting of low carbon free cutting steel are presented and compared with available experimental data obtained under similar cutting conditions. Good agreement between the numerical and experimental results is observed. 相似文献
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