Tribology of tool–chip interface and tool wear mechanisms
Tribology of tool–chip interface and tool wear mechanisms
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DOI：
10.1016/s0257-8972(01)01488-8
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发表时间：
2002-01
影响因子：
5.4
通讯作者：
H. O. Gekonde;S. Subramanian
中科院分区：
文献类型：
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作者：
H. O. Gekonde;S. Subramanian
在刀具-切屑界面处的摩擦学现象控制切屑的形成和刀具磨损。随着金属切削速度从低速增加到中速，刀具-切屑界面处的摩擦学条件趋于从滑动变为卡滞，从而逐渐产生部分分段切屑。一旦咬合开始，在第二剪切区发生热塑性剪切，提高工具-切屑接触处的局部温度。热激活过程开始。通过扩散机制将刀具溶解到切屑中，导致刀具凹坑磨损。凹坑的最大深度位于距刀具切削刃一定距离处。在较高的切削速度下，切屑分割是由主剪切区的热塑性剪切局部化引起的，从而导致高温上升和刀具切削刃附近的刀具快速磨损。讨论了刀具-切屑界面摩擦学现象随切削速度的变化。定量的数据报告显示的开始在金属切削和后果的扣押促进溶解磨损的扩散机制。将咬合条件下计算的温度分布与测量的弹坑深度分布进行比较，表明弹坑磨损与相变相耦合。在咬合的条件下，涂层在抑制溶解磨损中的作用在球墨铸铁和低碳钢中使用TiN和HfN来证明，TiN和HfN是在工件（钢基体）中具有最小溶解度的化合物。
The tribological phenomenon at the tool–chip interface controls chip formation and tool wear. As metal cutting speed increases from low to moderate speeds, the tribological conditions at the tool–chip interface tend to change from sliding to seizure, giving rise progressively to partially segmented chips. Once seizure sets in, thermoplastic shear occurs in the secondary shear zone, raising the local temperature at the tool–chip contact. Thermally activated processes set in. Dissolution of the tool into the chip takes place by a diffusion mechanism, causing tool crater wear. The maximum depth of the crater is located at some distance away from the cutting edge of the tool. At higher cutting speeds chip segmentation is caused by thermoplastic shear localisation at the primary shear zone causing high temperature rise and rapid tool wear close to the cutting edge of the tool. The change in tribological phenomenon at the tool–chip interface as a function of cutting speed is discussed. Quantitative data are reported to show the onset of seizure in metal cutting and the consequences of seizure in promoting dissolution wear by diffusion mechanism. The calculated temperature distribution under seizure conditions is compared with measured crater depth profiles to show that crater wear is coupled with phase transformation. Under conditions of seizure, the role of coatings in suppressing dissolution wear is demonstrated in both ductile iron and low carbon steel using TiN and HfN, which are compounds having the least solubility in the workpiece (steel matrix).