陶瓷刀具在大型薄壁件加工中的应用

从分析优质合金钢的薄壁件质量不合格的原因入手，结合难加工材料的高速切削机理，改进工艺流程。提出利用陶瓷刀具实现大型薄壁件高速切削的可行性，澄清了利用陶瓷刀具加工的几个误区，并对切削过程中的注意事项及切削参数的选择提出一些建议。实际使用表明在中型机床上利用陶瓷刀具可以实现大型薄壁件的高速切削，实现以车代磨，从而降低了生产成本，提高了生产效率，满足了产品的质量要求。     

薄壁零件切削稳定性的研究现状

高速切削技术的发展,使得薄壁结构件的高效、精密加工成为可能。但是,由于薄壁件的刚性较差,在加工过程中很容易发生变形。因此,薄壁零件的切削稳定性一直是高速切削加工领域内的一个难点。本文对于薄壁件切削稳定性的研究现状进行了讨论,并分析了薄壁件加工过程中加工变形的影响因素。     

高精度薄壁开口筒件加工变形控制方案的研究

针对薄壁结构开口筒件切削加工中筒体变形问题进行了分析与研究.通过建立薄壁开口筒件切削加工力学模型、ANSYS有限元变形分析模型,结构切削试验,得到了薄壁开口筒件变形的基本规律,并提出了控制筒件变形相应的工艺措施.结果表明,薄壁开口筒件变形模式与工艺路线、工装、夹紧力位置、切削用量、刀具角度等因素的组合有关;采用合理的工艺路线、工装、夹紧位置可以减小加工变形,提高加工精度,是三种控制薄壁开口筒件加工变形的有效工艺措施.     

薄壁零件高速铣削加工技术研究

薄壁零件高速铣削加工具有传统铣削加工无可比拟的优势,是薄壁零件切削加工的发展方向。本文分析和讨论了薄壁零件高速铣削加工过程中涉及到的加工工艺、切削刀具、数控编程以及装夹方式等关键技术问题,介绍了提高薄壁零件加工精度、表面质量和加工效率的技术方法和工艺措施。     

高速切削加工中刀具材料的合理选择

高速切削加工技术是近几十年来发展迅猛的一项先进制造技术,已经成为国内外研究的热点之一。刀具材料影响着高速切削加工技术的广泛应用。刀具材料经历了高速钢-硬质合金-陶瓷-超硬材料等不断发展的过程,切削速度和加工效率得以不断提高。本文分析了在高速切削加工中常用的刀具材料,并针对常用的被加工材料阐述了高速切削刀具材料的选择方法。     

7075-T651铝合金薄壁件加工仿真研究

针对薄壁件加工中难以选择刀具几何参数和切削参数等问题,基于金属切削仿真软件Advant Edge建立了硬质合金圆柱铣刀高速铣削7075-T651铝合金薄壁件有限元模型,采用单因素试验法仿真分析了切削参数对切削力、切削温度的影响,以及圆柱铣刀的前角和刀尖圆弧半径对切削性能的影响。为薄壁零件加工中选择合理刀具几何参数与切削参数提供了可靠的依据。     

三维有限元分析在高速铣削温度研究中应用

高速切削过程中切削温度对刀具磨损、工件加工表面完整性及加工精度有极大的影响。应用有限元法对高速铣削铝合金薄壁件过程中工件与刀具接触面温度、工件内部的温度分布进行了仿真研究,仿真过程中考虑了切削速度、进给量对切削温度的影响。通过红外热像仪对不同主轴转速下工件表面温度的测量,验证了仿真结果与试验结果比较接近。得出在高速切削铝合金过程中,随着切削速度的增加,刀具与工件接触区的温度变化存在二次效应。该结论对铝合金薄壁件加工具有重要的实用价值。     

高速切削加工的刀具材料及其合理选择

刀具技术的不断发展是高速切削加工得以实施的工艺基础。高速切削的刀具技术包括刀具材料、刀具结构的优化和刀具的装夹技术等。刀具材料影响着高速切削加工技术的广泛应用。刀具材料的发展是高速钢——硬质合金——陶瓷——超硬材料，高性能材料不断取代低性能材料，切削速度和加工效率不断提高。目前适用于高速切削的刀具主要有：涂层刀具、陶瓷刀具、金属陶瓷刀具、立方氮化硼(CBN)刀具、聚晶金刚石(PCD)刀具以及性能优异的高速钢和硬质合金复杂刀具等。     

陶瓷刀具在高速切削加工中的应用

高速切削加工是实现高效和精密、超精密切削的一种新的加工技术,刀具是实现高速加工的关键因素之一.介绍了陶瓷刀具的性能特点,高速切削加工中陶瓷刀具切削用量以及刀具参数的选择.     

刀具几何参数对高速铣削SiCp/Al复合材料温度的影响研究

研究了PCD刀具高速铣削铝基复合材料时刀具几何参数对切削温度的影响。利用A baqus软件,对PCD刀具高速铣削SiCp/Al复合材料薄壁件进行仿真模拟。刀具回转直径为10 mm,切削线速度为300 m/min,改变刀具的前角和后角仿真出铣削时刀具和工件的温度场。通过对比数据,得出刀具角度变化对切削温度的影响规律,从而为实际加工时刀具几何参数的选择提供依据。     

高速切削技术研究

高速切削是继数控技术之后,给机械制造业带来又一次革命性变化的一项高新技术。本文从机床、刀具、工件、工艺等方面讨论了高速切削的技术开发情况。     

高速干切滚齿工艺系统切削热全过程传递模型

高速干切滚齿工艺消除了切削油/液的使用,是一种绿色高效的齿轮制造工艺。切削热伴随着高速干切滚齿工艺全过程且区别于传统湿式滚切工艺,是造成干切滚刀磨损和机床热变形的重要因素,直接影响制造成本和加工精度。根据干切滚刀周期性断续传热特性,综合考虑切削热在切屑、工件、干切滚刀、冷却介质以及滚齿机床加工空间的传递规律,提出将高速干切滚齿工艺系统切削热的发生与传递全过程划分为三个阶段的研究思想,从关系模型和热传递方程两个层面建立了高速干切滚齿工艺系统切削热全过程传热模型,包括切削接触界面热传递、切削区域热传递和机床加工空间热传递三个阶段的模型,然后基于工艺仿真试验对所建模型进行了应用研究,揭示了高速干切滚齿工艺系统的切削热在工件、干切滚刀、切屑中的动态变化规律,最后通过试验验证了模型的有效性。     

高速加工切削用量选择分析

高速加工切削用量的选择主要考虑加工效率、加工质量、刀具磨损和加工成本。不同刀具加工不同工件材料时,切削用量会有很大差异。切削用量的选择是高速加工中的重要内容,切削用量的大小对加工效率、加工质量、刀具磨损和加工成本均有显著影响。本文对高速加工的切削用量选择问题进行了分析,给出了若干原则和建议。     

高速切削温度动态变化规律的数值模拟

切削温度与刀具磨损、工件加工表面完整性及加工精度密切相关,其变化规律反映出高速切削过程本质的重要方面。本文应用数值模拟,对高速切削加工过程中切屑、工件和刀具三方面的温度随切削速度、进给量、切削深度的动态变化进行了研究,探讨了其变化规律,其结论有助于优化高速切削工艺及建立高速切削数据库。     

Cutting heat dissipation in high-speed machining of carbon steel based on the calorimetric method

The cutting heat dissipation in chips, workpiece, tool and surroundings during the high-speed machining of carbon steel is quantitatively investigated based on the calorimetric method. Water is used as the medium to absorb the cutting heat; a self-designed container suitable for the high-speed lathe is used to collect the chips, and two other containers are adopted to absorb the cutting heat dissipated in the workpiece and tool, respectively. The temperature variations of the water, chips, workpiece, tool and surroundings during the closed high-speed machining are then measured. Thus, the cutting heat dissipated in each component of the cutting system, total cutting heat and heat flux are calculated. Moreover, the power resulting from the main cutting force is obtained according to the measured cutting force and predetermined cutting speed. The accuracy of cutting heat measurement by the calorimetric method is finally evaluated by comparing the total cutting heat flux with the power resulting from the main cutting force.     

Characterization of abrasive grain’s behavior and wear mechanisms

Grinding is a finishing process largely used in motor industry, aeronautics, space industry and precision cutting tool manufacturers. The grinding process can be summarized by the action of a grinding wheel on a workpiece. The wheel is constituted by abrasive grains. Thus grinding is in fact the action of grains on the workpiece. The grain behavior changes according to numerous parameters (geometry, mechanical characteristics, wear mechanisms). In some cases abrasive wear is observed while micro-cutting is obtained in some other cases.In this paper two useful and complementary experimental approaches for the interface physics understanding is presented. The study of the cutting power is carried out using a high-speed scratch test device in order to understand the grain behavior and the wear mechanisms for several wheel surface speeds. In this paper an approach for the specific abrasion energy computation is also presented.     

基于DEFORM 3D的钛合金高速车削有限元仿真

应用DEFORM 3D软件对钛合金高速车削进行仿真研究,分析了不同切削参数下切削力和切削温度的规律,研究发现背吃刀量和进给量对主切削力的影响较大,切削力与主切削力变化基本一致,切削速度对主切削力的影响不明显,但后者对切削温度具有显著影响;研究了工件和刀具温度场的变化规律以及工件所受应力和刀具的磨损情况,发现最高温度出现在切削刃邻近2mm区域内,且温度最高处刀具磨损程度最大,工件最大应力在第一变形区和工件接触区邻近。     

Implementation of an open-loop control technique for high-speed micropositioning in a single-point diamond turning process

An investigation is undertaken to minimize residual vibrations associated with high-speed, low-amplitude machining processes. A numerically computed input signal allows the system to follow a desired output trajectory once an accurate dynamic model of the system is developed. Specific application of this method is focused on controlling tool motion while cutting micron depth surface features into a flat, rotating workpiece during a single-point diamond turning process. The synthesized input signal, applied open-loop, is used to eliminate transient surface features that are created by uncontrolled motion of the tool when it is plunged into the workpiece surface during the cutting process. Controlled and uncontrolled cuts are shown to demonstrate a significant improvement in resulting surface features.     

Cutting heat dissipation in high-speed machining of carbon steel based on the calorimetric method

The cutting heat dissipation in chips, workpiece, tool and surroundings during the high-speed machining of carbon steel is quantitatively investigated based on the calorimetric method. Water is used as the medium to absorb the cutting heat; a self-designed container suitable for the high-speed lathe is used to collect the chips, and two other containers are adopted to absorb the cutting heat dissipated in the workpiece and tool, respectively. The temperature variations of the water, chips, workpiece, tool and surroundings during the closed high-speed machining are then measured. Thus, the cutting heat dissipated in each component of the cutting system, total cutting heat and heat flux are calculated. Moreover, the power resulting from the main cutting force is obtained according to the measured cutting force and predetermined cutting speed. The accuracy of cutting heat measurement by the calorimetric method is finally evaluated by comparing the total cutting heat flux with the power resulting from the main cutting force. __________ Translated from Journal of South China University of Technology (Natural Science Edition), 2006, 34(11): 1–4 [译自: 华南理工大学学报(自然科学版)]