基于粗糙度形成机理的曲面高速铣精加工参数选用

为在曲面精加工中获得理想的表面粗糙度,通过分析表面粗糙度的形成机理,建立了粗糙度与走刀行距、进给率关系的数学模型;通过实验,建立了高速曲面铣削时粗糙度与加工倾角、主运动线速度关系的图谱,实现了在生产过程中按照加工目标的表面粗糙度确定相应的走刀行距、进给率、加工倾角、主运动线速度等加工参数.研究结果表明,该研究对提高加工...     

0Cr18Ni9不锈钢焊缝高速铣削表面粗糙度试验研究

采用正交试验方法进行0Cr18Ni9不锈钢焊缝高速铣削试验,分析铣削参数对表面粗糙度的影响规律,并建立表面粗糙度的经验预测模型。结果表明:随着主轴转速的增大,表面粗糙度值减小,而随着进给速度、切削深度的增大,表面粗糙度值增大,进给速度对表面粗糙度的影响较为明显;较高的主轴转速和较低的进给速度的交互作用有利于减小表面粗糙度值,提高表面质量。     

高速铣削时钛合金刀具的磨损及对工件表面粗糙度的影响

观察高速铣削钛合金刀具时后刀面及被加工表面的形貌,通过对刀具后刀面磨损量和被加工表面粗糙度值的测量研究了刀具磨损对被加工表面粗糙度的影响,揭示了钛合金铣削加工时提高表面质量的规律。     

曲面加工表面粗糙度几何仿真

目前采用高速铣削方式加工具有曲面结构的零件非常普遍,而在曲面加工的过程中几何因素对已加工曲面的表面粗糙度具有一定的影响。为了提高加工效率和加工质量,普遍的方法是采用仿真软件。文中以MATLAB为平台,构建双三次Bezier曲面的工件模型,并结合走刀行距和进给量以及切削速度等加工参数,对影响表面粗糙的因素进行分析,同时提出具体的仿真算法,并且在实际应用中加以验证。     

Surface roughness modeling in Laser-assisted End Milling of Inconel 718

Inconel 718 is a difficult-to-machine material while products of this material require good surface finish. Therefore, it is essential for the evaluation and prediction of surface roughness of machined Inconel 718 workpiece to be developed. An analytical model for the prediction of surface roughness under laser-assisted end milling of Inconel 718 is proposed based on kinematics of tool movement and elastic response of workpiece. The actual tool trajectory is first predicted with the consideration of overall tool movement, elastic deformation of tool, and the tool tip profile. The tool movements include the translation in feed direction and the rotation along its axis. The elastic deformation is calculated based on the previously established milling force prediction model. The tool tip profile is predicted based on the tool tip radius and angle. The machined surface profile is simulated based on the tool trajectory with elastic recovery, which is considered through the comparison between the minimum thickness and actual cutting thickness. Experiments are conducted in both conventional and laser-assisted milling under seven different sets of cutting parameters. Through the comparison between the analytical predictions and experimental measurements, the proposed model has high accuracy with the maximum error less than 27%, which is more accurate for lower feed rate with error less than 3%. The proposed analytical model is valuable for providing a fast, credible, and physics-based method for the prediction of surface roughness in milling process.     

高速铣削7050-T7451铝合金表面粗糙度研究

高速铣削广泛用于航空铝合金材料的加工,以7050-T7451铝合金材料为试验对象,运用正交试验方法分析研究了铣削该铝合金材料时,切削速度、切削深度、切削宽度和每齿进给量4个因素对表面粗糙度的影响规律,并通过多元非线性回归分析得出表面粗糙度的经验公式.研究结果表明:加工表面呈交叉织网状形貌,表面粗糙度随每齿进给量和铣削深度的增大而增大,随切削速度的增大而减小,切宽对铝合金表面粗糙度的影响不明显.铣削参数对表面粗糙度的影响显著性依次为:每齿进给量fz切削速度v轴向切削深度ap径向切削宽度ae.     

铝合金高速切削表面粗糙度影响因素研究

为有效降低高速切削中铝合金的表面粗糙度值,通过多因素正交试验和单因素试验对各铣削参数进行研究,结果显示:各参数对铝合金表面粗糙度影响程度从大到小的顺序是:切削深度、主轴转速、每齿进给量、行距,且转速为18000r/min,每齿进给量为0.075mm,行距和每齿进给量一致,选择较小的切削深度时,在铝合金表面可获得较好的加工质量。     

The significance of surface topography in engineering

All machining processes leave characteristic topographic features on the surfaces of components. This paper reviews a wide range of examples in which the surface topography of a component has been found to bear a significant effect on its function. Problems in manufacture which are related to surface roughness requirements are also disccused.     

钛合金精密铣削的表面粗糙度研究

进行了精密铣削钛合金粗糙度试验研究,采用正交分析方法,分析切削三要素铣削速度、进给量、铣削深度对表面粗糙度的影响规律,试验采用直径为2mm的3刃铣刀进行铣削。试验结果表明：表面粗糙度影响顺序依次是进给量、切削速度、切削深度。进给量选为0．01—0．05mm／min时,表面粗糙度随进给量的增大而增大。铣削深度在60—150μm、铣削速度在18．84-47．10m／min试验范围内,最优铣削速度为37．68m／min。而铣削深度对钛合金表面粗糙度影响不大。     

铝合金高速切削表面粗糙度的实验研究

使用硬质合金刀具对LY12高强度铝合金进行了高速精密切削试验。研究了切削条件、切削用量对加工表面粗糙度的影响。高速切削试验表明:提高切削速度与减小进给量有利于改善铝合金工件的加工表面质量;当切削速度超过某一范围后,随着切削速度的进一步提高,加工表面粗糙度的降低并不明显。     

高速铣削RoyAlloy模具钢的表面粗糙度研究

为分析高速铣削RoyAlloy模具钢时表面粗糙度的变化规律,在基于刀具位姿的基础上,由正交试验综合研究前倾角、侧偏角、主轴转速、每齿进给量、铣削深度和铣削宽度等铣削参数的影响,并建立了预测模型。     

基于弹塑性理论的高速铣削表面粗糙度力学建模

基于分子—机械摩擦理论,提出了已加工表面残留高度的力学模型。并根据热—弹塑性大变形理论,对材料的流动应力方程(非线性)进行了分析,推导出了材料的应变硬化、应变率和温度与切削变形应力增量的关系,研究了不同材料(45钢和3Cr2Mo模具钢)已加工表面残留高度的实验结果,分析了材料物理性能对加工表面粗糙度的影响。     

表面形貌的Motif评定方法及其发展

Motif方法是一种新的表面形貌评定方法，通过设定不同的阈值，可以将波度和表面粗糙度分离开来，它强调大的轮廓峰和谷对功能的影响，在评定中选取了重要的轮廓特征，而忽略了不重要的特征，介绍了2维Motif的参数和合并条件，然后对3维Motif方法的定义，评定参数及算法等进行了综述，并提出了推广这一评定方法需要注意的问题。     

微细精密铣削表面粗糙度DRSM研究

DRSM方法具有序贯性、可旋转性、模型的稳健性以及试验次数少等优点,近年来逐渐运用在微细精密车铣加工运用中,笔者着重对微细精密铣削表面粗糙度进行DRSM分析,得出了微细精密铣削条件下工艺参数对表面粗糙度的影响规律,并进行了表面粗糙度的预测,有较强的理论实践和现实意义。     

微铣金属表面微沟槽结构的粗糙度及形貌分析

为了提高和改善微沟槽表面质量,设计了高速微铣削实验,研究了微沟槽底面表面粗糙度和侧壁残留毛刺的变化规律。从理论角度引入了已加工表面的形成机理,建立了微观表面粗糙度理论模型,提出了刀具跳动对侧壁形貌变化影响的规律。利用三轴联动精密微细铣削机床加工微细直沟槽,并选取主轴转速、轴向切深、进给速度、刀具跳动量和材料组织结构为研究因素。采用多因素正交实验和极差分析法,对表面粗糙度值进行数值分析。铝合金,钢和钛合金三类微沟槽底面对应的最佳表面粗糙度值变化范围分别为1.073~1.481 μm,0.485~0.883 μm,0.235~0.267 μm;无刀具跳动钛合金微沟槽壁毛刺的最大高度为7.637 μm,而当刀具存在0.3 μm的径向综合跳动量时对应的微槽壁毛刺的最大高度为21.79 μm。铣削参数对表面粗糙度值的影响按从大到小依次为进给速度、主轴转速、轴向切深,且随着进给速度和轴向切深的增大,表面粗糙度值增大;随着主轴转速的增大,表面粗糙度值先减小后增大;在相同加工条件下,若微圆弧刀刃无磨损,微刀具的跳动量对微直沟槽侧壁表面质量有较大影响。同时,不同金属材料特性也是影响微沟槽表面质量的潜在因素。     

高速铣削曲面工件的表面粗糙度仿真

在实际生产中,空间曲面一般采用行切法加工。无论是三坐标还是两坐标联动铣削,走刀行距的选择对加工表面粗糙度都有很大影响。本文针对球头铣刀对Bezier双三次曲面工件的高速铣削,结合走刀行距经验公式,提出了一种表面粗糙度的仿真算法,并通过仿真实例进行了验证。     

Surface topography and lubrication in sheet-metal forming

The conjoint interaction of blank surface roughness and lubricant at the tool/metal interface in sliding contact has been investigated. Strips of commercial purity aluminium sheet were pulled through steel dies designed to give partial simulation of the conditions which exist in the flange and die radius profile regions of the deep drawing process. Different types of surface roughness were imposed upon the strips prior to testing and the lubricants used were tallow, Shell Tellus 27, Bonderlube 142 and graphite grease. A new, hybrid surface roughness parameter, Bearing Length Product (BLP), was defined and shown to have a functional relationship with the coefficient of friction.The two mechanisms of boundary and hydrostatic lubrication were considered to be active in the tests and it was shown that their relative contribution is a function of distinct surface roughness features. Evidence also suggests that the stick-slip, observed in tests with two of the lubricants, was caused by two quite different mechanisms.     

Surface topography and properties of frictional contacts

The influence of surface topography on contacting solids is considered. The rough surface model is suggested and is used for the calculation of some tribological contact characteristics. A rough surface is modelled by a set of asperities of regular shape (wedge, cone, cylindrical, spherical segment), of differing height. A simple height distribution function and asperity shape function are used. These functions may be integrated analytically in further calculations.The surface model is used for calculation of one of the main contact parameters - real contact pressure (or real contact area) and other principal contact parameters, such as deformation, number of contact spots, average spot area, average distance between contact spots and intercontact gap.It is shown how the above parameters may be used for the calculation of such operational contact characteristics as friction coefficient, wear rate and electrical and thermal resistance.     

高速铣削AF1410高强度钢的实验研究

高强度钢具有优异的机械性能和广阔的应用,但切削加工较为困难,存在加工效率低,加工表面质量差等问题.以AF1410高强度钢为研究对象,应用高速铣削的加工方法,使用涂层硬质合金刀片,对AF1410高强度钢进行了高速铣削实验,研究分析了在高速切削条件下刀具磨损、切削力、切削温度以及已加工表面粗糙度的变化规律.研究发现以TiC...