Analysis of large edge breakage of WC-Co cemented carbide tool blades emerging in precision grinding process
Analysis of large edge breakage of WC-Co cemented carbide tool blades emerging in precision grinding process
复制标题
WC-Co硬质合金刀具刀片精磨过程中出现大刃口破损分析
DOI：
10.1016/j.jmrt.2022.06.103
复制
发表时间：
2022-06
期刊：
影响因子：
--
通讯作者：
Ahmed Mohamed Mahmoud Ibrahim
中科院分区：
文献类型：
--
作者：
Wei Li;Ju Wen-Liang;Long Gui;Wang Bo;Mohammad S. Alsoufi;Ammar Elsheikh;Ahmed Mohamed Mahmoud Ibrahim
分析了WC-Co硬质合金材料切割刀片精密磨削后的刃口损伤特征。边缘损伤特征表现为微小裂纹和锯齿状连续断边。从刃口残余应力、显微组织、元素含量变化等方面探讨了刃口损伤的主要原因。结果表明，崩落刃后表面的平均残余压应力值为−1745.7 MPa，远大于磨削前的记录值（−578.6 MPa）。表面C、W元素含量明显增加（分别从28.35%增加到34.29%和54.51%~ 61.06%）。WC晶粒的增多和Co含量的降低会导致相应材料的结合强度降低，容易导致边部裂纹和空洞。采用碗状树脂结合剂金刚石砂轮对WC-Co硬质合金进行了磨削试验，并采用正交试验法进行了优化。优化结果表明，单次研磨量是影响加工时间的最大因素。对叶片报废率影响最大的因素是转速和单次磨削量。综合考虑加工效率和加工质量，采用改进后的组合方式进行磨削加工，实验结果表明：叶片报废率为10%，单个叶片加工时间为205 s。
This paper analyzes the edge damage characteristics of the cutting blade made of WC-Co cemented carbide material after precision grinding. The edge damage characteristics present tiny cracks and serrated continuous edge breakage. The main causes of the edge damage were explored regarding the edge residual stress, microstructure, and the change of element content. The results show that the value of the average residual compressive stress on the rear surface of the caving edge is −1745.7 MPa, which is much larger than that recorded before grinding (−578.6 MPa). The content of element C and element W on the surface increased obviously (from 28.35% to 34.29% and 54.51%–61.06% respectively). The increase of WC grains and the decrease of Co content will lead to the decrease of the bonding strength of the corresponding material, which will easily lead to the crack at the edge and cave. The grinding experiment of WC-Co cemented carbide was carried out with a bowl shape resin-bonded diamond grinding wheel and was optimized with the orthogonal experimental method. The optimized results show that the single grinding amount was the biggest factor affecting the processing time. The angular speed of rotation and the single grinding amount was listed as the factors that had the greatest influence on the blade rejection rate. Considering the processing efficiency and quality comprehensively, adopting the improved combination during the grinding process, the experimental results were as follows the blade rejection rate is 10%, and the processing time of a single blade is 205 s.