College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, China.
PLoS One. 2023 Aug 25;18(8):e0290760. doi: 10.1371/journal.pone.0290760. eCollection 2023.
This study focuses on systematically revealing how cutting parameters influence the surface integrity of ball-end hard milled surface of AISI D2 steel and proposing optimization scheme from surface integrity, wear resistance and fatigue resistance perspective based on response surface methodology respectively. Results can be summarized into three aspects. Firstly, radial depth of cut with percent contribution ratio (PCR) 62.05% has a decisive influence on surface roughness, followed by spindle speed 13.25% and feed per tooth 6.63%. The work hardening degree was raised from 12.5% to 38.4% when spindle speed changed from 8000 rpm to 2000 rpm. Spindle speed and radial depth of cut are the most significant factor influencing residual stress. The PCR of spindle speed and radial depth of cut reached 73.47% and 18.63% for residual stress in feed direction, 47.11% and 37.51% in step-over direction, respectively. High residual compressive stress can be generated by lowering spindle speed and radial depth of cut benefiting from the aggravated squeeze between ball-end milling cutter and workpiece. Secondly, too small feed per tooth or too small radial depth of cut should be avoided from wear resistance point because though the surface microhardness can be improved, the surface quality will also be deteriorated. The combination of high spindle speed, small feed per tooth together with small radial depth of cut can meet the wear resistance and the machining efficiency requirement. Finally, a medium-sized cutting parameter combination should be adopted to realize satisfying material removal rate and fatigue resistance. This study can be used to guide the selection of cutting parameters during ball-end milling of hardened AISI D2 steel for dies/molds manufacturing industries.
本研究旨在系统揭示切削参数如何影响 AISI D2 钢球头铣削表面的表面完整性，并分别从表面完整性、耐磨性和抗疲劳性的角度提出基于响应面法的优化方案。研究结果可归纳为三个方面。首先，径向切深（PCR）62.05%对表面粗糙度有决定性影响，其次是主轴转速（13.25%）和每齿进给量（6.63%）。当主轴转速从 8000rpm 降低到 2000rpm 时，加工硬化程度从 12.5%提高到 38.4%。主轴转速和径向切深是影响残余应力最显著的因素。主轴转速和径向切深的 PCR 分别达到了进给方向残余应力的 73.47%和 18.63%，步距方向残余应力的 47.11%和 37.51%。通过降低主轴转速和径向切深，可以在球头铣刀和工件之间产生较大的挤压，从而产生较高的残余压应力。其次，从耐磨性的角度来看，应避免每齿进给量过小或径向切深过小，因为虽然表面显微硬度可以提高，但表面质量也会恶化。高主轴转速、小每齿进给量与小径向切深的组合可以满足耐磨性和加工效率的要求。最后，应采用中等切削参数组合来实现令人满意的材料去除率和抗疲劳性。本研究可用于指导模具制造业中淬硬 AISI D2 钢球头铣削的切削参数选择。
