The main purpose of this study is to investigate the influence of tool geometry (cutting edge angle, rake angle, and inclination angle) and to optimize tool wear and surface roughness in hard turning of AISI 1055 (52HRC) hardened steel by using TiN coated mixed ceramic inserts. The results show that the inclination angle is the major factor affecting the tool wear and the surface roughness in hard turning. With the increase in negative rake and inclination angles, the tool wear decreases, and the surface roughness increases. However, the surface roughness will decrease when the inclination angle increases to overpass a certain limit. This is a new and significant point in the research of the hard turning process. From this result, the large negative inclination angle (λ = −10°) should be applied to reduce the surface roughness and the tool wear simultaneously. With the optimal cutting tool angles in the research, the hard machining process is improved remarkably with decreases of surface roughness and tool wear 8.3% and 41.3%, respectively in comparison with the standard tool angles. And the proposed tool-post design approach brings an effective method to change the tool insert angles using standard tool-holders to improve hard or other difficult-to-cut materials turning quality.

这项研究的主要目的是研究工具几何形状（切削刃角，前角和倾斜角）的影响，并通过使用TiN涂层混合材料在AISI 1055（52HRC）硬化钢的硬车削中优化工具磨损和表面粗糙度陶瓷插件。结果表明，在硬车削中，倾斜角是影响刀具磨损和表面粗糙度的主要因素。随着负前角和倾斜角的增加，刀具磨损减少，表面粗糙度增加。然而，当倾斜角增加到超过一定极限时，表面粗糙度将减小。这是硬车削工艺研究的一个新的重要意义。根据这个结果，应采用较大的负倾角（λ= -10°），以减少表面粗糙度并同时降低刀具磨损。通过研究中的最佳切削刀具角度，与标准刀具角度相比，硬加工工艺得到了显着改善，表面粗糙度和刀具磨损分别降低了8.3％和41.3％。所提出的刀架设计方法带来了一种有效的方法，该方法可以使用标准刀架来改变刀具插入角度，从而提高硬质或其他难切削材料的车削质量。