淬硬钢切削加工表层特征及其使用性能研究

发布时间：2018-04-01 15:32

本文选题：硬切削　切入点：表层特征　出处：《哈尔滨理工大学》2015年硕士论文

【摘要】：淬硬钢是典型的难加工材料,由于其具有较高的强度和硬度等机械物理性能,在高端装备制造过程中得到了广泛的应用,淬硬钢切削加工工件表面三维粗糙度、白层和残余应力等表层特征因素,对零件服役过程中的精度、耐磨性、寿命和疲劳强度等都有着重要的影响,深入研究加工表层特征形成机理及使用性能已成为淬硬钢切削技术推广应用的关键。本文以淬硬钢切削加工表层特征为研究对象,探究硬切削加工表层特征的变化规律、表层特征和疲劳寿命之间的关系。通过切削试验,研究切削参数和刀具磨损对残余应力、白层和表面三维粗糙度等表层特征因素的影响规律,进行疲劳寿命试验,分析表层特征对疲劳寿命的影响;在此基础上建立淬硬钢切削加工表层特征的预测评价模型。首先,设计硬切削加工表层特征试验,并用扫描电子显微镜、X射线衍射仪、激光共聚焦显微镜、超景深显微镜等检测仪器,对加工表层特征进行微观检测。分析并阐述加工表层特征形成机制及工艺参数对表层特征的影响规律。其次,进行硬切削疲劳性能试验,试验分析加工试件疲劳性能,获取不同切削参数和刀具磨损状况下加工表层特征变化规律对工件使役性能的影响规律,分析疲劳试样的损伤形态和表层特征对疲劳性能的影响。最后,根据淬硬钢切削试验的数据结果,建立基于BP神经网络的淬硬钢切削加工表层特征预测模型,对不同的切削参数和刀具磨损情况下的工件表面特征进行预测;在此基础上结合疲劳性能试验结果,采用模糊综合评价的方法,建立切削加工表层特征模糊评价模型,实现淬硬钢切削加工表层特征的预测和评价。
[Abstract]:Hardened steel is a typical refractory material, because of its high mechanical and physical properties, such as strength and hardness, it has been widely used in the manufacture of high-end equipment.The surface characteristic factors, such as white layer and residual stress, have important influence on the precision, wear resistance, life and fatigue strength of the parts in service.It has become a key point for the popularization and application of hardened steel cutting technology to study the forming mechanism and performance of machining surface features.In this paper, the surface features of hardened steel cutting are studied, and the relationship between surface features and fatigue life is explored.The effects of cutting parameters and tool wear on residual stress, white layer and surface 3D roughness were studied, and fatigue life tests were carried out to analyze the influence of surface features on fatigue life.On this basis, a prediction and evaluation model for the surface features of hardened steel cutting is established.First of all, we design the surface feature test of hard cutting, and use scanning electron microscope (SEM), laser confocal microscope (LSCM), hyper-depth microscope and other testing instruments to detect the surface features of the machined surface.The formation mechanism of machining surface features and the influence of process parameters on surface features are analyzed and expounded.Secondly, the fatigue properties of hard cutting specimens are tested and analyzed, and the effects of different cutting parameters and tool wear on the workpiece performance are obtained.The effects of damage morphology and surface characteristics of fatigue specimens on fatigue properties were analyzed.Finally, according to the data of hardened steel cutting test, a BP neural network model for predicting the surface features of hardened steel cutting is established, and the surface characteristics of workpiece under different cutting parameters and tool wear are predicted.Based on the results of fatigue test and fuzzy comprehensive evaluation method, a fuzzy evaluation model of cutting surface features is established to predict and evaluate the surface features of hardened steel cutting.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG506.7

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