金属切削毛刺的预测预报技术研究

金属切削毛刺是切削加工中产生的常见现象,它严重地影响着产品的精度和使用性能,有必要对毛刺的预测预报进行深入系统的研究.系统地概括了国内外对金属切削毛刺的预报预测研究现状,分析了有限元法在毛刺形成过程、形态及尺寸大小和界限转换条件的定量或定性预测预报中的具体应用,为系统深入地研究切削毛刺奠定了坚实的理论基础.     

微细切削毛刺发展研究

微细切削加工中形成的毛刺严重降低了被加工微型零部件的精度和棱边质量,影响了工件的使用性能,对微细切削的毛刺研究有利于推动微细切削技术的发展。系统概述了国内外微细切削毛刺的研究进展,重点阐述了研究者对微细切削毛刺形成机理、影响因素及预测预报技术的研究,并在分析微细切削特殊切削环境的基础上,结合尺度效应理论研究了微细切削毛刺的形成机理,指出了微细切削毛刺研究尚存的主要问题,同时确立了今后深入开展微细切削毛刺研究的发展方向。     

金属切削毛刺专家知识系统的开发

毛刺是金属切削加工中产生的常见现象。研究开发出了金属切削毛刺专家知识系统，为管理切削实验所测的毛刺数据、查询毛刺类型与尺寸、优化选择加工参数和进行切削毛刺形成的动力学仿真等奠定了基础。进而，为实现切削毛刺的预报与控制开辟了新途径。     

金属切削毛刺预报研究现状分析

阐述了金属切削毛刺形成预报研究的背景,并国内外学者的研究现状进行了分析研究,并且做出了比较,再在总结与归纳出金属切削毛刺预报的研究现状中尚存在的一些问题的基础上,指出在科技不断发展的现在,对金属切削加工技术的要求也越来越高,由于金属切削毛刺研究说涉及的领域很多,所以也给研究带了了新的机遇与挑战。最后指出了解决金属切削毛刺形成预报的关键问题和研究的发展方向。     

基于神经网络的金属切削毛刺专家系统的研究及应用

机械加工中毛刺的形成与存在影响、制约着精密与超精密加工和自动化加工技术的发展。基于神经网络理论,构建并开发了金属切削毛刺专家系统(Ujs),通过对神经网络的设计,并作为推理机制,以数据库为训练样本,建立了毛刺形态、尺寸与切削条件之间的映射模型,应用于金属切削毛刺的控制及预报。结合车削实验,比较了系统预报结果与实验结果,取得了较好的吻合。神经网络专家系统的建立为解决毛刺预报与控制提供了一条有效的途径。     

金属切削毛刺数据库系统的设计

毛刺的产生和存在是金属切削加工中普遍存在的问题 ,它直接影响了工件的加工精度及质量。基于数据库和Java ,研究了金属切削毛刺数据库系统的设计 ,实现了切削毛刺数据的管理、切削毛刺类型与尺寸大小及加工参数的查询 ,进一步丰富和完善了金属切削毛刺的预报与控制理论。     

金属切削毛刺形成与控制技术研究进展

本文系统概述了国内外对于毛刺形成机理及控制技术的研究进展,重点阐述了预测毛刺形成的解析模型和有限元模型、毛刺形成过程的实验研究以及控制毛刺形成的加工工艺和非标刀具,分析了亟待解决的问题,指出了金属切削毛刺形成机理和控制技术研究的方向.     

PCD面铣刀切削刃对低刚性的缸盖面的毛刺影响

在夹具系统刚性不足的情况下,铝合金缸盖燃烧室和覆盖面很容易出现毛刺。文中介绍了PCD铣刀出现毛刺的原因。研究PCD面铣刀切削刃的几何参数对于毛刺影响的研究。提出了一种在刚性不足的切削系统下,达到既没有振纹又没有毛刺的方法。     

微切削毛刺形成机理及研究进展综述

概述了微切削毛刺的形态、分类及其生成机理;阐述了微切削毛刺的仿真分析研究进展;在微切削毛刺的试验研究进展方面,分析了切削工艺参数、刀具几何、切削方式和辅助工艺对微切削毛刺的影响;介绍了几种常用复合材料加工毛刺的研究现状;根据毛刺的成形机理和加工方式,综述了去除毛刺的工艺方法与设备,提出了去毛刺装置的性能要求;最后总结了微细毛刺研究方面的不足,并指出了将来研究的方向。     

少无毛刺切削技术的研究进展

在系统概述国内外少无毛刺切削加工技术研究进展的基础上,根据机械加工实际需要,给出了主动控制或减小金属切削毛刺的基本原则,探索出少无毛刺的主要途径。此外,分析了几种切削加工技术的具体应用。指出了目前尚需解决的一些主要问题,确立了今后深入开展金属切削毛刺研究的方向。     

Analytical modelling of slot milling exit burr size

A computational model was recently proposed by authors to approximate the tangential cutting force and consequently predict the thickness of the exit up milling side burr. To calculate the cutting force, the specific cutting force coefficient with respect to material properties was used. The model was sensitive to material yield strength and few cutting and tool geometrical parameters. However, the effects of cutting speed, tool coating, and tool rake angle on burr size were neglected. Other phenomena that could affect the burr size such as friction and abrasion were not taken into account either. Therefore, in the current work, a mechanistic force model is incorporated to propose a burr size prediction algorithm. The tangential and radial forces are calculated based on using specific cutting force coefficients in each direction. Furthermore, using the new approach, the burr size is predicated and the effects of a broad range of cutting parameters on burr size and friction angle are evaluated. Experimental values of burr size correlated well with prediction. It was found that the cutting speed has negligible effects on force and burr size. Lower friction angle was recorded when using larger feed per tooth. Consequently, thinner exit up milling side burr was obtained under high friction angle.     

Influence of size effect on burr formation in micro cutting

Burr is an important character of the surface quality for machined parts, and it is even more severe in micro cutting. Due to the uncut chip thickness and the cutting edge radius at the same range in micro cutting process, the tool extrudes the workpiece with negative rake angle. The workpiece flows along the direction of minimum resistance, and Poisson burr is formed. Based on the deformation analysis and experiment observations of micro cutting process, the factor for Poisson burr formation is analyzed. It is demonstrated that the ratio of the uncut chip thickness to the cutting edge radius plays an important role on the height of Poisson burr. Increasing the uncut chip thickness or decreasing the cutting edge radius makes the height of exit burr reduce. A new model of micro exit burr is established in this paper. Due to the size effect of specific cutting energy, the exit burr height increases. The minimum exit burr height will be obtained when the ratio of uncut the chip thickness to the cutting edge radius reaches 1. It is found that the curled radius of the exit burr plays an important role on the burr height.     

Burr analysis in microgrooving

Microburr formation affects badly on product's quality, especially the finishing surface. Besides, deburring techniques on microcutting are almost impossible or high cost. Understanding burr formation phenomena and minimizing burr size in correlation with cutting conditions and material properties, in this case, are more appropriate. For the purpose of exploring the burr phenomena in micrometal cutting, two cases of burr formation in grooving micropatterns are introduced in the paper. The burr happens along the cutting direction—side burr—of prism pattern, and the other happens at the exit edge of the pattern in the cutting direction—exit burr—of pyramid pattern. Besides, the exit break off which occurs during the exit burr formation is also studied. The analytical solutions for predicting the burr and break off size in each case are also proposed and compared with experiments.     

Characteristics and mechanism of top burr formation in slotting microchannels using arrayed thin slotting cutters

This paper investigates the characteristics and mechanism of top burr formation, and the influence of cutting conditions on top burr formation in slotting microchannels on stainless steel (SS304L) using arrayed thin slotting cutters. Saw-like top burr that is a combination of Poisson part and tear part was observed in the experiments. A 3D finite element model was developed for analysis of the top burr formation processes. The mechanism of top burr formation was proposed based on a series of stress contours and the progressive deformation of microchannel edge obtained from simulation. The process of top burr formation can be divided into four stages: Poisson part initiation, Poisson part development, tear part formation and tear part toppling. The top burr height was found to be largely determined by feed and cutting speed, while the top burr width was found to be strongly influenced by cutting depth, feed and cutting speed.     

Investigation on the burr formation mechanism in micro cutting

It is desirable to minimize burr formation for improving part quality. This paper presents an investigation on the burr formation mechanism in micro cutting by taking into consideration the stress distribution around the cutting edge arc. The influences of the uncut chip thickness and the cutting edge radius on burr formation were investigated. Poisson burr is attributed to the side flow of the stagnation material at the bottom of the cutting edge arc. The stress distribution at the cutting edge arc has great influence on Poisson burr formation. The burr height decreases to the minimum value and then increases with reducing the uncut chip thickness due to the change of the maximum stress distribution. An optimum machining strategy also is suggested in micro milling of snake-shaped groove microstructure.     

Finite element simulation for burr formation near the exit of orthogonal cutting

A coupled thermo-mechanical model of plane-strain orthogonal metal cutting including burr formation is presented using the commercial finite element code. A simulation procedure based on Normalized Cockroft–Latham damage criterion is proposed for the purpose of better understanding the burr formation mechanism and obtaining a quantitative analysis of burrs near the exit of orthogonal cutting. The cutting process is simulated from the transient initial chip formation state to the steady state of cutting, and then to tool exit transient chip flow by incrementally advancing the cutting tool. The predicted burr profile is compared with experimental data and found to be in reasonable agreement. The effect of the tool conditions and cutting conditions on the burr formation process was also investigated.     

FORMING PRINCIPLE OF TWO SIDE-DIRECTION BURR AND IT‘S PREDICTION IN METAL CUTTING

OgyAbethect The burr is one of the common phenomena occutring in metal cutting OPerations. The mat hematical- mechaniedmodel of two side-direction burr fOrmation and transformation is established with plane stress-strain thcory, based on theorthogonal cutting. The main laws of fOrmation and change of the burr are revealed, and it is confirmed by expedmentresult, which first realizes prediction of the forming and changing of the two sidesdirection burr in metal cutting operation.Key wOrds:Me…     

Micro-burr formation and minimization through process control

This paper presents an investigation on micro-burr formation in machining. Micro-cutting is compared with conventional cutting in terms of cutting process characteristic and cutting conditions. In this paper, tungsten–carbide micro-mills were used to cut holes (in a drilling-like process) to investigate top burr formation. The size and type of burr created in stainless steel 304 are studied as a function of machining variables, which are feed, cutting speed and cutting edge radius, to help illuminate the micro-burr formation mechanisms. A series of experiments was conducted to study tool life as a function of cutting conditions. Tool life, here, is defined as the number of holes created before a significant increase in burr height. Based on experimental results, contour charts for predicting burr formation as well as tool life are developed to minimize burr formation and to improve tool life. The model, which includes the effect of feed, cutting speed, and the interaction between the two, predicted the burr height and tool life values with an accuracy of about ±15%.     

Development of intelligent system to minimize burr formation in face milling

The exit burr generated in the face milling operation at the edge of the workpiece usually requires deburring processes to enhance the level of precision of the parts. This paper is to geometrically understand the formation of the exit burr in the face milling operation on the arbitrary shaped workpiece with multiple feature such as hole, spline, and arc so that we can suggest the cutting conditions and tool path to minimize the burr formation on the given workpiece in the early design stage. The burr formation mechanism in each type of burr is classified based on the experimental results. A database is developed to store and predict burr formation results. A Windows based program is developed with the algorithm including three steps, i.e., the feature identification, the cutting condition identification, and the analysis on exit burr formation. We can predict which portion of the workpiece would have the exit burr in advance so that we can manage to find a way to minimize the exit burr formation in an actual cutting. Here, the idea of critical burr length is introduced as a criterion in optimization.