In the machining operations, final surface finish and dimensional accuracy are the most specified customer requirements. Hard turning machining operation using cubic boron nitride tool as an alternative of grinding process is a type of turning operation in which hardened steel are machined with the hardness greater than 45 HRc. During the hard turning operation because of the hard condition, the variations of surface finish and dimensional accuracy are completely different from that of the traditional turning operation. Thus, the variation of surface finish and dimensional accuracy under various cutting parameters has been investigated in the hard turning with cubic boron nitride tools. The extracted knolwdge can be used for developing a knowledged base expert system. In order to have a comprehensive study, the variation of vibration, cutting forces, and tool wear has also been considered. The obtained results showed that depth of cut and spindle speed have the greatest effect on the dimensional accuracy, while feed rate is the most important factor affecting the surface roughness. The analysis of the vibration and tool wear proved that the flank wear has insignificant influence on the dimensional accuracy, whereas the vibration effect is considerable. The experimental results showed that when the feed rate is gradually increased from 0.08 to 0.32, the dimensional deviation first decreases unexpectedly until the lowest value is achieved at 0.16 mm/rev, then by further increasing the feed from 0.16 to 0.32 mm/rev, the dimensional deviation increases significantly. It was also seen that the best dimensional accuracy is achieved at the lowest level of the cutting depth, the medium level of the feed rate, and the spindle speed lower than its moderate level. The best surface roughness of 0.312 μm was obtained at 0.08 mm/rev feed rate, 0.5 mm depth of cut, 2000-rpm speed, and 1.2 mm insert nose radius, which is comparable with the surface finish obtained by the grinding operation.

中文翻译：

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切削参数对立方氮化硼刀具对MDN250钢进行硬车削时尺寸精度和表面光洁度的影响，以开发知识渊博的基础专家系统

在加工操作中，最终表面光洁度和尺寸精度是客户最指定的要求。使用立方氮化硼刀具作为磨削工艺的替代品的硬车削加工操作是一种车削操作，其中以大于45 HRc的硬度加工硬化钢。由于条件恶劣，在硬车削加工中，表面光洁度和尺寸精度的变化与传统车削加工完全不同。因此，在立方氮化硼刀具的硬车削中，已经研究了各种切削参数下的表面光洁度和尺寸精度的变化。提取的knolwdge可用于开发知识丰富的基础专家系统。为了全面研究振动的变化，还考虑了切削力和工具磨损。结果表明，切削深度和主轴转速对尺寸精度影响最大，而进给速度是影响表面粗糙度的最重要因素。对振动和刀具磨损的分析证明，后刀面磨损对尺寸精度的影响不大，而振动效果却相当可观。实验结果表明，当进给速度从0.08逐渐增加到0.32时，尺寸偏差首先出乎意料地减小，直到达到最低值0.16 mm / rev，然后再将进给速度从0.16 mm / rev增加到0.32 mm / rev。尺寸偏差明显增加。还可以看到，在最小的切削深度下可获得最佳的尺寸精度，进给速度的中等水平，而主轴速度低于其中等水平。在0.08 mm / rev的进给速度，0.5 mm的切削深度，2000 rpm的速度和1.2 mm的刀尖半径下，可获得0.312μm的最佳表面粗糙度，这与通过研磨操作获得的表面光洁度相当。