Fundamental Aspects of Metal Cutting and Cutting Fluid Action
Fundamental Aspects of Metal Cutting and Cutting Fluid Action
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金属切削和切削液作用的基本方面
DOI：
10.1111/j.1749-6632.1951.tb54246.x
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发表时间：
1951
影响因子：
5.2
通讯作者：
H. Ernst
中科院分区：
文献类型：
--
作者：
H. Ernst
仅仅在几十年前，人们还不太可能认真考虑在专门讨论润滑基本方面的专著中纳入一篇关于金属切削的论文。金属切割是一个车间程序，很难受到物理学家的认真关注。今天，金属切削被许多人认为是物理学家和化学家都非常感兴趣的复杂过程：对于物理学家来说，这是因为具有已知剪切方向和剪切面的高应变和巨大应变率的独特塑性条件，以及异常高的摩擦系数值;对于化学家来说，由于芯片-工具界面化学反应的独特条件，其中切削液在非常高的局部温度和压力的条件下遇到高度应变和新暴露的（新生的）金属表面。在介绍这篇论文时，大量使用了电影来显示在各种条件下切屑形成的过程。这些照片是通过显微镜拍摄的，速度从每秒64帧到3000帧不等。这些场景是从作者实验室从事金属切削研究的25年来不同时期的影片中选取的。这里将尽可能地使用从这些影片中选出的画面和典型切屑横截面的显微照片来说明所提出的事实。切屑形成的基本机理现在已经很好地确定了。在我们自己和其他人的工作中，已经表明，在所有金属切削操作中，切屑形成过程的几何形状是相同的，例如，车削、铣削、拉削、刨削、钻孔等。在每一种情况下，切屑、刀具和工件的垂直于切削刃的横截面都与显微照片（图1和图2）中所示的一样。工具或刀具的面可以从切削刃向后倾斜，如图1所示，以提供传统的正前角，或者从切削刃向前倾斜，如图2所示，以提供负前角。具有负前角的铣刀齿的典型示例如图3所示。这是一个帧从电影采取了t 3000帧每秒，显示了一个硬质合金刀片铣刀删除芯片的强硬合金钢（NE 94443）t 504英尺/分钟。切屑和工件垂直于切削刃的横截面的显微照片。在类似的研磨操作中，如图4所示。从这张显微照片上可以明显看出，这涉及到两个物理过程：（1）形成切屑的剪切过程;（2）切屑相对于工具面的滑动。这些过程已经在以前发表的几篇关于切屑几何和力学的论文中进行了详细的分析和讨论。
Only a few decades ago, it is unlikely that serious thought would have been given to the inclusion of a paper on metal cutting in a monograph devoted to fundamental aspects of lubrication. Metal cutting was a shop procedure, hardly to be dignified by the serious attention of physicists. Today, metal cutting is recognized by many as a complex process of intense interest to both physicists and chemists: to physicists, because of the unique plasticity conditions of high strain and enormous strain rate with known direction and plane of shear, and unusually high values of coefficient of friction; and to chemists, because of the unique conditions for chemical reactions at the chip-tool interface, where the cutting fluid encounters a highly strained and freshly exposed (nascent) metal surface under conditions of very high local temperature and pressure. In presenting this paper, extensive use was made of motion pictures to show the process of chip formation under various conditions. These pictures were taken through the microscope a t speeds ranging from 64 to 3000 frames per second. The scenes presented were selected from films made a t various times during the past 25 years in the author’s laboratory, in the course of metal cutting research. Selected frames from these films and photomicrographs of typical chip cross sections will be used here, in so far as it is possible, to illustrate the facts set forth. The basic mechanisms involved in chip formation have now been well established. In the course of our own work, and others, it has been shown that the geometry of the chip forming process is identical in all metal cutting operations, e.g., turning, milling, broaching, planing, drilling, etc. In every case, a cross section through chip, tool, and workpiece, perpendicular to the cutting edge, appears somewhat as in the photomicrographs, FIGURES 1 and 2. The face of the tool or cutter may either be inclined backward from the cutting edge, as in FIGURE 1, to provide the conventional positive rake, or be inclined forwird from the cutting edge, as in FIGURE 2, to provide negative rake. A typical example of a milling cutter tooth with negative rake is shown in FIGURE 3. This is a frame from a film taken a t 3000 frames per second, showing a carbide tipped milling cutter removing a chip of tough alloy steel (NE 94443) a t 504 feetjmin. A photomicrograph of a cross section through the chip and workpiece perpendicular to the cutting edge. in a similar milling operation, is shown in FIGURE 4. From this photomicrograph, it is evident that two physical processes are involved: (1) a shearing process which forms the chip; and (2) a sliding of the chip against the tool face. These processes have been analyzed and discussed in detail in several previously published papers dealing with the geometry and mechanics of chip This paper,