超声波加工工程陶瓷孔的研究

对超声波加工工程陶瓷孔进行了研究 ,分析了材料去除机理 ,建立了超声波加工工程陶瓷孔时的材料去除率模型。由公式知 :材料去除率随静载荷、工具振幅、磨粒直径的增大而增大 ,随着材料断裂韧性和硬度的升高而降低 ,并实验验证了理论推导的材料去除率公式     

超声波加工工程陶瓷孔的研究

对超声波加工工程陶瓷孔进行了研究,分析了材料去除机理,建立了超声波加工工程陶瓷孔时的材料去除率模型。由公式知：材料去除率随静载荷、工具振幅、磨粒直径的增大而增大,随着材料断裂韧性和硬度的升高而降低,并实验验证了理论推导的材料去除率公式。     

基于超声波研磨加工机理的影响因素研究

根据硬脆材料具有很高的硬度和脆性特点,建立了超声波研磨加工硬脆材料去除理论模型,从理论上分析了超声波研磨加工硬脆材料的去除原理和加工优势,详细地分析了加工间隙、磨粒大小和超声波声压对材料的去除率和加工质量的影响.研究表明,基于超声波研磨加工在最佳组合条件下能够有效提高工件表面质量,实现精密超精密加工.     

电镀金刚石线锯超声振动切割多晶硅材料工艺研究

通过电镀金刚石线锯在超声振动下切割多晶硅的实验,研究了工艺参数对材料去除率的影响,建立了单颗金刚石磨粒材料去除模型,分析了金刚石粒度、静压力和线速度与材料去除率的关系.分析表明:基于超声波线锯切削条件下,适当提高金刚石粒度、静压力和线速度有利于提高材料去除率.施加超声振动后金刚石锯切加工效率平均提高1～2.5倍.     

超声波数控加工中工具振幅的简易测量

超声波加工中，工具振幅在材料去除中起着重要作用，研究振幅对材料去除率的影响，需要对工具振幅进行定量测量。介绍了前人测量振幅的几种常用方法，并提出一种超声波数控加工中振幅测量的简易方法。     

超声波激振刀具镗孔的试验研究

对超声波激振刀具镗孔进行试验,得到了以车代磨,以车代研的效果。对超声波振动镗孔的规律及机理进行了探讨。这项工艺可用于难加工材料及有色金属的深孔加工。     

高温合金GH4169的电火花加工工艺性研究

高温合金GH4169是制造航空发动机的重要材料。用电火花加工镍基高温合金GH4169时,峰值电流、脉宽、脉间、间隙电压等电参数是重要控制因素,而表面粗糙度和材料去除率是衡量工艺效果的性能指标。利用单一工艺参数试验考察了各电参数对表面粗糙度和材料去除率的影响。通过对多工艺参数正交试验结果进行极差分析,得出了各电参数对表面粗糙度和材料去除率影响的主次顺序。最后,在正交试验的基础上,利用灰关联分析法,得到了最优的加工参数组合,并进行了试验验证。     

紫铜电极负极性加工ZL302基础工艺试验研究

为实现铸造铝合金ZL302的高效电火花加工,在系统试验设计的基础上,进行了紫铜电极负极性加工ZL302的基础工艺试验,获得了材料去除率vm和电极损耗率vE与电参数之间的经验回归数学模型,并依此进行了工艺参数优化.研究结果表明,峰值电流ie、脉冲宽度ti是影响材料去除率vm和电极损耗率vE的主要工艺参数,电压Sv、脉冲间隔t0对材料去除率vm和电极损耗率vE等工艺指标也有影响.试验所得经验回归模型的置信度为95%,可用于指导实际生产.     

旋转集束电极多通道烧蚀试验研究

基于多通道放电原理,设计了旋转集束电极多通道烧蚀加工装置,并使用该装置进行多通道烧蚀加工工艺试验,研究了氧气压力、脉冲宽度和低压电流对材料去除率的影响。结果表明:氧气压力增高,材料去除率呈现先增大后不变的趋势;脉冲宽度增大,材料去除率先增大后减小,且脉冲宽度为250μs时的材料去除率最高,达到12 mm3/min;随着低压电流的增大,材料去除率呈现线性增大趋势。     

钛铝合金电火花加工工艺参数影响实验

为研究钛铝合金电火花加工工艺参数对材料去除率的影响,通过四因子二水平的全因子析因实验,确定了材料去除率的显著影响因子为电极极性、脉宽、占空比和峰值电流。通过最陡上升路径法,找到了材料去除率最大值对应的参数范围,并以此为基础设计中心复合响应曲面实验,得到了材料去除率的拟合公式,计算出材料去除率理论最大值及其对应的加工参数。实验验证了材料去除率拟合公式的正确性,并给出材料去除率拟合公式适用的参数范围。     

A Study on Process Parameters of Ultrasonic Assisted Micro EDM Based on Taguchi Method

Experimental investigation of ultrasonic assisted micro electro discharge machining was performed by introducing ultrasonic vibration to workpiece. The Taguchi experimental design has been applied to investigate the optimal combinations of process parameters to maximize the material removal rate and minimize the tool wear. Analysis of variance (ANOVA) was performed and signal-to-noise (S/N) ratio was determined to know the level of importance of the machining parameters. Based on ANOVA, ultrasonic vibration at 60% of the peak power with capacitance of 3300 PF was found to be significant for best MRR. The machining time plays a significant role in the tool wear. The results were confirmed experimentally at 95% confidence interval.     

Finite element prediction of material removal rate due to electro-chemical spark machining

Electro-chemical spark machining (ECSM) is an innovative hybrid machining process, which combines the features of the electro-chemical machining (ECM) and electrodischarge machining (EDM). Unlike ECM and EDM, ECSM is capable of machining electrically non-conducting materials. This paper attempts to develop a thermal model for the calculation of material removal rate (MRR) during ECSM. First, temperature distribution within zone of influence of single spark is obtained with the application of finite element method (FEM). The nodal temperatures are further post processed for estimating MRR. The developed FEM based thermal model is found to be in the range of accuracy with the experimental results. Further the parametric studies are carried out for different parameters like electrolyte concentration, duty factor and energy partition. The increase in MRR is found to increase with increase in electrolyte concentration due to ECSM of soda lime glass workpiece material. Also, the change in the value of MRR for soda lime glass with concentration is found to be more than that of alumina. MRR is found to increase with increase in duty factor and energy partition for both soda lime glass and alumina workpiece material.     

不同电极材料的短电弧铣削加工效率研究

短电弧铣削加工是一种新型的放电加工,它进一步提高了放电加工效率。论述了短电弧加工材料去除机制、去离子原则和热现象,分析了余热对材料去除率(MRR)的影响。研究了短电弧铣削加工效率的主要指标——MRR,在不同工具、工件电极的材料组合下,分析峰值电流、脉冲时间、脉冲间隔、进给速度、气压等工艺因素对MRR的影响规律。实验表明:不同电极材料组合的MRR存在差异;在大多数放电条件下,石墨电极和45碳钢工件获得较高的MRR,而紫铜电极和镍基高温合金GH4169工件获得较低的MRR。     

基于灰色预测模型电火花线切割工艺参数优化

针对电火花线切割加工机制的不确定性,工艺参数与工艺指标具有高度非线性关系;设计正交实验,分析脉宽、占空比、加工电流、丝速和跟踪系数对SKD?11材料去除率（ MRR）的影响;分别建立逐次广义回归模型（ GRM）和灰色预测模型（ GFM）,并对两个模型进行实验验证和比较,寻求出最佳的工艺参数。验证实验表明,所建立的灰色预测模型（ GFM）能够对实际加工的材料去除率（ MRR）进行精确的预测。     

SVR-PSO算法在慢走丝线切割参数优化中的应用

针对慢走丝线切割加工中难以同时获得较快加工速度和较优表面质量的问题,从其加工参数与加工指标之间的高非线性关系入手,选取水压、脉冲时间、脉冲宽度、峰值电流和进给速率作为优化参数,以表面粗糙度(Ra)、材料去除率(MRR)作为优化指标,设计正交实验;创新运用支持向量机(SVR)结合粒子群算法(PSO)建立其多目标预测优化模型,得到最优加工参数。结果表明:所建立的多目标预测优化模型优化效果十分显著,相同Ra下MRR平均提高32%;相同MRR下Ra同比下降25%。     

Rotary ultrasonic machining of ceramic matrix composites: feasibility study and designed experiments

Ceramic matrix composites (CMC) are enabling materials for a number of high-temperature and demanding applications in aerospace, power generation, ground transportation, nuclear, environmental, and chemical industries. Tremendous progress has been made in technology development, manufacturing, commercialization, and applications of CMC over the last few years. However, significant challenges (such as the lack of specifications, databases, and in-service repair methodology, and high machining cost) still remain for their widespread applications. In this paper, rotary ultrasonic machining (RUM) is introduced into drilling holes on CMC panels for the first time. The feasibility to machine CMC using RUM is investigated. Cutting forces and material removal rates (MRR) are compared for machining of CMC with and without ultrasonic vibration and for two types of CMC materials and one typical advanced ceramic material (alumina). Chippings at the hole exit are also observed under a microscope. Furthermore, the paper presents the results of a designed experimental investigation into RUM of CMC. A three-variable two-level full factorial design is employed to reveal main effects as well as interaction effects of three RUM process parameters (spindle speed, feedrate, and ultrasonic power). The process outputs studied include cutting force, MRR, and hole quality (in terms of chipping dimensions).     

Kinematic view of tool life in rotary ultrasonic side milling of hard and brittle materials

Experiments are conducted to study the mechanism of side milling in rotary ultrasonic machining (RUM). The study shows that RUM has less tool wear than grinding at the lateral direction of the cutter under the same conditions. The kinematics of diamond grits is employed for the theoretical analysis. In addition, by using slim diamond cutters, two different machining strategies are used to side mill a microstructure and grooves on a semi-sphere. An improvement strategy of material removal rate (MRR) is also discussed based on the experimental study.     

Modeling of material removal rate in electric discharge grinding process

The mechanism of material removal in electric discharge grinding (EDG) is very complex due to interdependence of mechanical and thermal energies responsible for material removal. Therefore, on the basis of conceived process physics for material removal, an attempt has been made to predict the material removal rate (MRR). The proposed mathematical model is based on the fundamental principles of material removal in electric discharge machining (EDM) and conventional grinding processes. The inter-dependence of the thermal and mechanical phenomena has been realized by scanning electron microscopy (SEM) characterization of the samples machined at different processing conditions. The key input process parameters like pulse on time, pulse current, gap voltage, duty cycle, pulse off time, frequency, depth of cut, wheel speed and table speed are co-related with MRR for three distinct idealized processing conditions. The constant showing the extent of interdependence of two phenomena were evaluated by experimental data. The obtained expressions of MRR have been validated for processing conditions other than those used for obtaining constants. It was found that the discharge energy plays prominent role in material removal. The percentage difference in experimental findings and theoretical predictions was found to be less than 3%.     

An investigation of ultrasonic-assisted electrical discharge machining in gas

This study focuses on using ultrasonic to improve the efficiency in electrical discharge machining (EDM) in gas medium. The new method is referred to as ultrasonic-assisted electrical discharge machining (UEDM). In the process of UEDM in gas, the tool electrode is a thin-walled pipe, the high-pressure gas medium is applied from inside, and the ultrasonic actuation is applied onto the workpiece. In our experiment, the workpiece material is AISI 1045 steel and the electrode material is copper. The experiment results indicate that (a) the Material Removal Rate (MRR) is increased with respect to the increase of the open voltage, the pulse duration, the amplitude of ultrasonic actuation, the discharge current, and the decrease of the wall thickness of electrode pipe; and (b) the surface roughness is increased with respect to the increase of the open voltage, the pulse duration, and the discharge current. Based on experimental results, a theoretical model to estimate the MRR and the surface roughness is developed.     

镍基高温合金Inconel718的超高效电火花电弧复合加工

提出了一种超高效电火花电孤复合铣削镍基高温合金Ineonel718的加工方法．构建了一种新型大功率电源,主要由高压脉冲电源和低压大功率直流电源组成。在冲液和电极旋转的作用下得到了非连续电弧,材料去除率可达13421mm3／min,相对电极损耗率可达1．71％。进行了复合加工和电火花加工的对比实验研究,分析了电极转速对材料去除率和相对电极损耗率的影响,并对加工表面特性进行了研究。