磨料水射流加工工程陶瓷工艺参数对加工质量的影响

研究用高压磨料水射流加工工程陶瓷，通过分析各工艺参数对加工质量的影响，提出了一种优选工艺参数的方法。     

工程陶瓷磨料水射流加工工艺参数对加工质量的影响

工程陶瓷材料是一种经过高温烧结而形成的无机非金属材料，由于它硬度高、脆性大，大多数冉瓷不导电、用传统的机械加工方法难以加工。近年来，高压磨料水射流加工工程陶瓷的方法越来越受到人们的重视。文章选择不同的工艺参数，作了大量试验，研究分析了各工艺参数对加工质量的影响。给出了一种优选工艺参数的方法。     

工艺参数对磨料水射流加工性能的影响

影响高压磨料水射流加工效果的主要因素是水压力、磨料参数、喷嘴的横向移动速度和喷嘴悬高等。采用新的工艺可以有效提高加工效率和加工质量，这些新工艺主要包括：多次切割、倾角切割和喷嘴往复摆动切割。     

磨料参数对工程陶瓷切割能力的影响

对高压射流中混入的磨料参数的选择进行了试验研究。并对磨料水射流的切割机理进行了分析；探讨了磨料参数的变化对切割工程陶瓷的影响。     

基于磨料水射流的陶瓷材料车削加工

工程陶瓷材料在航空航天等领域有着广泛的应用,由于工程陶瓷具有硬度大、脆性高、断裂韧性低等特点,其加工工艺性很差,极易产生细小裂纹和应力集中现象,影响陶瓷零件的综合性能及使用寿命。在研究磨料水射流单磨粒冲蚀机理的基础上,从磨料颗粒的能量入手,对氧化铝陶瓷材料的磨料水射流车削加工进行研究,建立了车削深度模型,并通过实验进行了验证,验证结果表明,该模型具有很高的可靠性。     

磨料水射流加工陶瓷的研究进展

综述了磨料水射流切割、钻削、铣削、车削陶瓷材料的研究进展,简要论述了磨料水射流加工原理,展望了应用前景,提出了今后的重点研究方向,对磨料水射流加工陶瓷材料研究有一定的参考性。     

磨料水射流切削加工

磨料水射流切削加工黑龙江矿业学院陈政国，董星磨料水射流切削加工技术是１９８３年新弓ｌ进切ｇ帅ｏ工领域的现代加工方法之一。它能够切削高硬度、高强度材料，如钛合金、金属基复合材料、陶瓷基复合材料等等，是弥补机械加工不足的又一种新加工方法。１．雷料水村流切...     

精密磨料微水射流加工系统研究

通过研究精密磨料微水射流加工机理,设计磨料微水射流系统结构,优化加工工艺,指导实际生产,扩大磨料微水射流应用。     

磨料水射流切割工艺参数的确定

磨料水射流(AWJ)切割加工在现代制造业中已得到广泛应用，AWJ本身的技术特性使得切割断面和切缝质量存在不足。为实现AWJ精确、高效切割，分析了射流、钻孔、切割及工件等AWJ切割工艺参数，并对直线段和曲线段切割速度确定方法进行了探讨。     

On the modelling of abrasive waterjet cutting

Abrasive waterjet cutting operates by the impingement of a high-velocity abrasive-laden waterjet against the workpiece. The jet is formed by mixing abrasive particles with high-velocity water in mixing tubes and is forced through a tiny sapphire orifice. The accelerated jet exiting the nozzle travels at more than twice the speed of sound and cuts as it passes through the workpiece.This cutting process is being developed as a net-shape and near-net-shape machining process for cutting many metals and hard-to-machine materials. The narrow kerf produced by the stream results in neither delimitation nor stresses along the cutting path. This new technology offers significant advantages over traditional processes for its ability to cut through most sections of dense or hard materials without the need for secondary machining, to produce contours, and to be integrated into computer-controlled systems.The abrasive waterjet cutting process involves a large number of process and material parameters which are related to the waterjet, the abrasive particles, and workpiece material. Those parameters are expected to effect the material removal rates and the depth of cut. The purpose of the present work is to propose a model which is capable of predicting the maximum depth of cut for different types of materials using different process parameters. A comparison of the results of the proposed model and the models reported in the literature is introduced along with a discussion of the limitations of those models.On leave from: Mechanical Engineering Department, Suez Canal University, Egypt.On leave from: Industrial Production Engineering Department, Mansoura University, Egypt.On leave from: Mechanical Power Engineering Department, Alexandria University, Egypt.     

Predictive depth of jet penetration models for abrasive waterjet cutting of alumina ceramics

A study of the depth of jet penetration (or depth of cut) in abrasive waterjet (AWJ) cutting of alumina ceramics with controlled nozzle oscillation is presented and discussed. An experimental investigation is carried out first to study the effects of nozzle oscillation at small angles on the depth of cut under different combinations of process parameters. Based on the test conditions, it is found that nozzle oscillation at small angles can improve the depth of cut by as much as 82% if the cutting parameters are correctly selected. Depending on the other cutting parameters in this study, it is found that a high oscillation frequency (10–14 Hz) with a low oscillation angle (4–6°) can maximize the depth of cut. Using a dimensional analysis technique, predictive models for jet penetration when cutting alumina ceramics with and without nozzle oscillation are finally developed and verified. It is found that the model predictions are in good agreement with the experimental results with the average percentage errors of less than 2.5%.     

Material removal in abrasive waterjet machining of metals Surface integrity and texture

An experimental study was conducted to determine the influence of material properties on the surface integrity and texture that results from abrasive waterjet (AWJ) machining of metals. A microstructure analysis, microhardness measurements, and profilometry were used in determining the depth of plastic deformation and surface texture that result from material removal. Models now available for dry abrasive erosion were adopted and found useful in understanding the influence of material properties on the hydrodynamic erosion process. It was found that the depth of subsurface plastic deformation is inversely proportional to a metals strength coefficient and extends the greatest depth near jet entry in the initial damage region (IDR). Furthermore, surface skewness in AWJ machining of metals increases with ductility and the corresponding critical strain for lip formation.     

A study of abrasive waterjet cutting of alumina ceramics with controlled nozzle oscillation

This paper presents and discusses an experimental investigation of abrasive waterjet (AWJ) cutting of alumina ceramics with controlled nozzle oscillation. Particular attention is paid to the effect of small oscillation angles on the various cutting performance measures. It is found that nozzle oscillation at small angles can equally improve the major cutting performance measures, if the cutting parameters are correctly selected. However, under high water pressures, high nozzle traverse speeds and large oscillation frequencies, nozzle oscillation may cause a decrease in some major cutting performance measures, such as surface finish. Plausible trends of cutting performance with respect to the process parameters are further considered. Finally, a predictive mathematical model for the depth of cut is developed and verified.     

Fracture mechanics-based model of abrasive waterjet cutting for brittle materials

Advanced engineering ceramic materials such as silicon carbides and silicon nitride have been used in many engineering applications. The abrasive waterjet is becoming the most recent cutting technique of such materials because of its inherent advantages.In the present study, two elastic-plastic erosion models are adopted to develop an abrasive waterjet model for cutting brittle materials. As a result, two cutting models based on fracture mechanics are derived and introduced. The suggested models predict the maximum depth of cut of the target material as a function of the fracture toughness and hardness as well as the process parameters.It is found that both models predict the same depth of cut within a maximum of 11%, for the practical range of process parameters used in the present study. The maximum depth of cut predicted by the suggested models are compared with published experimental results for three types of ceramics. The effect of process parameters on the maximum depth of cut for a given ceramic material is also studied and compared with experimental work. The comparison reveals that there is a good agreement between the models' predictions and experimental results, where the difference between the predicted and experimental value of the maximum depth of cut is found to be an average value of 10%.Nomenclature C abrasive efficiency factor, see equation (16) - C ₁,C ₂ c ₁/4/3, c₂/4/3 - c ₁,c ₂ erosion models constants, see equations (1) and (2) - d _a local effective jet diameter - d _j nozzle diameter - d _S infinitesimal length along the kerf - f ₁ ( _E ) function defined by equation (7) - f ₂ ( _E ) function defined by equation (8) - f ₃ ( _e ) function defined by equation (14) - g ₁ ( _E ) f ₁( _e )/f ₃ ² ( _e ) - g ₂ ( _e ) f ₂( _e /f ₃ ² ( _e ) - H Vickers hardness of the target material - h maximum depth of cut - K _c fracture toughness of target material - k kerf constant - M linear removal rate, dh/dt - m mass of a single particle - abrasive mass flow rate - water mass flow rate - P water pressure - Q total material removal rate, see equation (11) - R abrasive to water mass flow rates - r particle radius - S kerf length - u traverse speed - V material volume removal rate (erosion rate) - V idealised volume removal by an individual abrasive particle - particle impact velocity - ₀ initial abrasive particle velocity - x,y kerf coordinates - local kerf angle, Fig. 1 - _E jet exit angle at the bottom of the workpiece, Fig. 1 - particle density - _w water density On leave from: Mechanical Engineering Department, Suez Canal University, Egypt.On leave from: Mechanical Power Engineering Department, Alexandria University, Egypt.     

淹没磨料射流对金属材料切割性能影响的实验研究

在完全淹没条件下,以Q235号钢板为例,对射流压力、横移速度、靶距、磨料目数、喷嘴型号等主要切割参数进行了考察,分析了这些参数对金属。料切割深度的影响,为水下切割技术提供一些有价值的参考。     

A study on the use of single mesh size abrasives in abrasive waterjet machining

This paper details the studies on the use of single mesh size garnet abrasives in abrasive waterjet machining for cutting aluminum. The influence of three different single mesh size abrasives, pressure, traverse rate, and abrasive flow rate; on depth of cut, top kerf width, bottom kerf width, kerf taper, and surface roughness are investigated. Experiments designed using standard L9 orthogonal array and the analysis of variance helped in the determination of highly significant, significant and weakly significant cutting parameters. Single mesh size abrasives are found to yield decreased surface roughness than multi mesh size abrasives. Based on these studies, response equations are developed to predict the target parameters. Using single mesh abrasives, a practitioner not only can cut faster but also achieve reduced surface roughness.     

Effects of process parameters on surface roughness in abrasive waterjet cutting of aluminium

Abrasive waterjet cutting is a novel machining process capable of processing wide range of hard-to-cut materials. Surface roughness of machined parts is one of the major machining characteristics that play an important role in determining the quality of engineering components. This paper shows the influence of process parameters on surface roughness (R_a) which is an important cutting performance measure in abrasive waterjet cutting of aluminium. Taguchi’s design of experiments was carried out in order to collect surface roughness values. Experiments were conducted in varying water pressure, nozzle traverse speed, abrasive mass flow rate and standoff distance for cutting aluminium using abrasive waterjet cutting process. The effects of these parameters on surface roughness have been studied based on the experimental results.     

工程陶瓷材料电火花线切割加工的机理研究

针对如何提高工程陶瓷材料加工质量这一问题,对碳化硼工程陶瓷进行了电火花线切割加工的试验研究.介绍了工程陶瓷材料的电火花放电加工原理,通过对碳化硼工程陶瓷进行的电火花线切割加工工艺试验,探讨了电参数对工程陶瓷电火花线切割加工表面质量的影响规律.该研究对进一步深化电火花加工技术的基础理论,促进该技术在实际生产中的推广应用具有重要意义.     

Depth of cut models for multipass abrasive waterjet cutting of alumina ceramics with nozzle oscillation

An experimental study of the depth of cut in multipass abrasive waterjet (AWJ) cutting of alumina ceramics with controlled nozzle oscillation is presented. It is found that this cutting technique can significantly increase the depth of cut by an average of 50.8% as compared to single pass cutting without nozzle oscillation under the corresponding cutting conditions and within the same cutting time. Predictive models for the depth of cut are then developed. The modelling process starts with single pass cutting using a dimensional analysis technique and the particle erosion theories applied to alumina ceramics, before progressing to the development of the models for multipass cutting. The models are finally assessed both qualitatively and quantitatively with experimental data. It is shown that the model predictions are in good agreement with the experimental data with the average deviations of about 1%.