Bohdal Łukasz, Kukiełka Leon, Patyk Radosław, Kośka Katarzyna, Chodór Jarosław, Czyżewski Konrad
Department of Mechanical Engineering, Koszalin University of Technology, Racławicka 15-17 Street, 75-620 Koszalin, Poland.
Materials (Basel). 2021 Dec 24;15(1):107. doi: 10.3390/ma15010107.
The work concerns an analysis of the wear mechanisms of punches in the nibbling process. The nibbling process is the multiple punching of holes or external contours using circular punches, the diameter of which is much smaller than the size of the punched shapes. Analytical, numerical and experimental studies were carried out. In the analytical solution, formulas for determining the pressures in the contact zone were developed, thus enabling a simple estimation of the designed nibbling tools. In numerical studies, the influence of the punch rounding radius on the fatigue wear was investigated. It has been shown that the change in the punch cutting edge radius from r = 0 mm to r = 0.5 mm enables a seven-fold increase in the fatigue wear resistance. It was found that the change in the punch cutting edge rounding radius has an impact on the quality of the product (the greater the radius r, the worse the technological quality of the product). In experimental studies, the abrasive wear process was primarily investigated. For this purpose, the nibbling process was tested on S235JR + AR steel sheets with tools made of NC11LV/1.2379 steel without any coating and with an AlCrTiN layer. It was found that the special AlCrTiN layer used allowed for an increase in the resistance to abrasive wear, and thus increased the service life by approx. three times. The last element of the work is an assessment of the technological quality of the product after nibbling depending on the degree and type of stamp wear (quantitative and qualitative assessment).
这项工作涉及对冲裁过程中冲头磨损机制的分析。冲裁过程是使用圆形冲头多次冲孔或冲裁外部轮廓，冲头直径远小于被冲裁形状的尺寸。进行了分析、数值和实验研究。在解析解中，推导了确定接触区压力的公式，从而能够简单地评估设计的冲裁工具。在数值研究中，研究了冲头圆角半径对疲劳磨损的影响。结果表明，冲头切削刃半径从r = 0 mm变为r = 0.5 mm可使疲劳耐磨性提高7倍。发现冲头切削刃圆角半径的变化对产品质量有影响（半径r越大，产品的工艺质量越差）。在实验研究中，主要研究了磨料磨损过程。为此，在S235JR + AR钢板上使用由NC11LV/1.2379钢制成的无涂层和有AlCrTiN涂层的工具对冲裁过程进行了测试。发现使用的特殊AlCrTiN涂层可提高抗磨料磨损能力，从而使使用寿命提高约三倍。这项工作的最后一部分是根据冲模磨损的程度和类型（定量和定性评估）对冲裁后产品的工艺质量进行评估。
