【作者】 张昆；

【导师】 苏宏华；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2015， 硕士

【摘要】 单层金刚石砂轮由于磨粒硬度高、出露度高、容屑空间大的优点,在光学玻璃等脆硬材料的磨削加工中有着广泛的应用。但是单层金刚石砂轮存在一个固有缺陷,即表面磨粒尖端到回转中心的距离不一致。在磨削工件时,磨粒等高性不一致的现象就会复映到磨削表面,造成加工表面粗糙值高,难以满足精密加工要求,这限制了单层金刚石砂轮的应用。对单层金刚石砂轮进行精密修整是解决这一问题的有效方法。为此,本课题开展了基于机械化学综合效应的碟轮修整方法研究,分析了修整机理,进行了单层钎焊金刚石砂轮的修整实验,通过磨削K9光学玻璃对修整后的砂轮磨削性能进行了评价研究。本文的主要研究工作包括:(1)采用蝶形45钢作为修整工具进行了单颗金刚石和CBN磨粒的磨损实验,对比分析了金刚石磨粒和CBN磨粒的磨损速度与修整过程中磨粒的磨损机理。(2)建立了单层金刚石砂轮磨粒排布理想状态下在修整过程中单颗切厚变化的理论模型,分析了修整过程对材料去除机理的影响关系,提出了提高修整效率的参数优化方案。(3)使用碟轮修整装置对单层钎焊金刚石砂轮进行了修整实验研究,通过跟踪修整过程中磨粒形貌变化以及磨削K9玻璃表面质量的变化,评价了修整效果。(4)使用修整后的单层钎焊金刚石砂轮进行了K9光学玻璃磨削实验,研究不同磨削参数对磨削表面粗糙度,表面形貌,亚表面损伤的影响规律,通过计算单颗磨粒最大切厚分析了其影响机理,进一步评价修整后的单层钎焊金刚石砂轮的磨削加工性能。更多还原

【Abstract】 Monolayer diamond wheels are widely used in machining hard-brittle materials such as K9 optical glass due to high grit protrusion, strong grit-bond adhesion and long tool life, etc. But the application is always limited for the high roughness on the ground surface of the workpiece because the monolayer diamond wheel has an inherent weakness—the distances of the grit tips from the centre of gyration are unequal.To solve this problem, the monolayer diamond wheels should be precisely dressed. In this study, a series of researches were carried out on a new dressing method, namely plate wheel dressing, micro-removing the over-protruded grits through chemical-mechanical effect. Besides, a dressing experiment was carried out on a monolayer brazed diamond wheel. The grinding performance was evaluated through grinding K9 optical glass.The main contents are as follows:(1)Some single grit wearing experiments were carried out with diamond and CBN grits. Through comparing the wearing speeds of diamond grit and CBN grit, the dressing mechanism was analyzed.(2)A plate wheel dressing experiment was carried out on a monolayer brazed diamond wheel. The dressing effect was evaluated through grinding K9 optical glass during the dressing process. The changes of the grits were observed and the quality of the ground surface was measured.(3)A series of grinding experiments were carried out on K9 optical glass using the dressed monolayer brazed diamond wheel. The influence of the grinding parameters on the surface roughness, the surface topography and the subsurface damage was studied. The influence mechanism was analyzed in terms of the maximum undeformed chip thickness to evaluate the dressing effects.更多还原