切磨过程中花岗石材料去除机理研究

MATERIAL REMOVAL MECHANISMS IN SAWING AND GRINDING OF GRANITE

深入理解切磨过程中花岗石材料的去除机理是优化加工设备、加工工具以及加工参数的基础。本文研究了花岗石的断口表面、锯切表面、粗磨表面以及精磨表面形貌特征 ,并结合切磨过程中临界载荷、单颗金刚石磨粒所承受的切削力以及比能特征 ,对加工表面形成机理进行了分析。研究表明 ,材料的去除机理与单颗磨粒的最大切削厚度直接相关。随着单颗金刚石磨粒最大切削厚度的减小 ,花岗石的去除方式也逐渐由脆性断裂为主转为塑性流变为主。由于不同的材料去除机制对应不同的能量消耗 ,可以通过调节单颗磨粒的最大切削厚度控制材料的去除方式 ,进而控制能量消耗。因此 ,均匀的磨粒出露高度对于控制切磨过程中材料的去除机理和优化加工过程具有重要意义。

To effectively produce high-grade granite slabs demands a better understanding of the granite removal mechanisms during the process of sawing and grinding. SEM was used to check the characteristics of fractured, sawn, ground and polished granite surfaces. Average normal and tangential force components acted on each diamond grain, the minimum normal threshold load for lateral cracking and the specific energy, which is the energy consumed to remove per unit material, were calculated to evaluate the processes. It was found that with decreasing maximum depth of cut, average normal and tangential force components acted on each grain would be reduced. The specific energy was found to decrease with the maximum depth of cut, and the deformation mode on the machined granite surfaces gradually shifted from brittle fracture to plastic deformation. In order to control the removal mechanisms and optimize the machining processes, it is important to keep a uniform protrusion height of active diamond grains during sawing and grinding of granite.