单层有序CBN砂轮工作面状态表征与磨削性能研究

发布时间：2019-01-12 14:10

【摘要】：磨粒有序排布的单层钎焊CBN砂轮(以下简称单层有序CBN砂轮)因具有优异的磨削性能而在航空航天难加工材料的高效磨削加工领域具有广阔应用前景。前期磨削机理研究已经发现,单颗磨粒最大未变形切屑厚度(以下简称单颗磨粒切厚)会影响磨削力、磨削温度、砂轮寿命、磨削表面质量等。由于以往研究通常是假定砂轮表面每颗磨粒的切厚都相同,所以难以精确预测磨削加工结果。原因在于,砂轮实际工作面上由于不同磨粒之间的形态、出露高度等差异,导致不同磨粒在磨削过程中的单颗磨粒切厚并不相同,有时甚至具有较大差异。因此,本文从精确表征单层有序CBN砂轮工作面状态出发,建立单颗磨粒切厚分布模型,并分析切厚分布特征对磨削加工过程的影响,为准确预测磨削结果提供科学依据和基础数据。本文完成的主要研究工作及取得的结果如下:(1)提出采用复型法测量单层有序CBN砂轮的工作面形貌数据,并运用50×1047的矩阵描述砂轮工作面上每颗磨粒的出露高度和所处位置,由此实现对单层有序CBN砂轮工作面的精确表征。建立了单颗磨粒切厚分布计算公式,并根据单层有序CBN砂轮工作面地貌数据获得了单颗磨粒切厚分布特征(包括平均值与标准差)。(2)制作了单层有序CBN砂轮,并以GH4169镍基高温合金为加工对象开展了砂轮磨削磨损试验,阐明了砂轮工作面状态的演变规律,发现了砂轮磨损和磨削参数对单颗磨粒切厚分布特征的影响规律,为优化磨削工艺参数以调控单颗磨粒切厚分布特征提供了理论依据和基础数据。(3)通过磨削实验揭示了砂轮工作面状态对磨削力、磨削温度、磨削比能等过程参量、以及磨削表面粗糙度的影响规律,由此建立了单颗磨粒切厚分布特征与磨削过程参量及加工结果的关系模型,并进行了实验验证,发现误差可控制在10%以内。
[Abstract]:Single layer brazed CBN grinding wheel (hereinafter referred to as monolayer ordered CBN grinding wheel) has a broad application prospect in the field of high efficiency grinding of aerospace materials due to its excellent grinding performance. Previous research on grinding mechanism has found that the maximum undeformed chip thickness of single abrasive particle (hereinafter referred to as single abrasive particle thickness) will affect grinding force, grinding temperature, grinding wheel life, grinding surface quality and so on. It is difficult to predict the grinding results precisely because of the assumption that the cutting thickness of each abrasive particle on the surface of grinding wheel is the same. The reason lies in the fact that the cutting thickness of single abrasive grain in grinding process is different and sometimes even has great difference due to the difference of the shape and height of different abrasive particles in the actual working face of grinding wheel. Therefore, in order to accurately characterize the working face of single-layer ordered CBN grinding wheel, a single grain thickness distribution model is established in this paper, and the influence of cutting thickness distribution on grinding process is analyzed. It provides scientific basis and basic data for accurate prediction of grinding results. The main research work and the results obtained in this paper are as follows: (1) A compound method is proposed to measure the face morphology data of single-layer ordered CBN grinding wheel. A matrix of 50 脳 1047 is used to describe the exposed height and location of each abrasive particle in the grinding wheel face, and thus the precise representation of the single-layer ordered CBN grinding wheel face is realized. A formula for calculating the thickness distribution of a single abrasive particle is established. According to the geomorphological data of the single-layer ordered CBN grinding wheel face, the distribution characteristics of the single abrasive particle thickness distribution (including average value and standard deviation). (_ 2) are obtained, and the single-layer ordered CBN grinding wheel is made. The grinding wheel wear test was carried out with GH4169 nickel base superalloy as the processing object, the evolution law of grinding wheel working face state was clarified, and the influence of grinding wheel wear and grinding parameters on the distribution characteristics of single grain cutting thickness was found. The theoretical basis and basic data are provided for optimizing the grinding process parameters to control the distribution characteristics of single abrasive particle thickness. (3) through grinding experiments, the process parameters such as grinding force, grinding temperature and grinding specific energy of grinding wheel working face are revealed. Based on the influence of grinding surface roughness, the relationship between the distribution of single grain thickness and grinding process parameters and machining results is established. The experimental results show that the error can be controlled within 10%.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG580.1

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