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。     

磨料水射流的切割机制

研究了100MPa～400MPa高水压下磨料水射流（AWJ）的切割机制。根据射流与材料之间的相互作用过程,建立和验证了AWJ切割过程模型。揭示了典型材料的切割特征（切割深度、切口宽度和冲蚀量）与切割变量（水压、靶距和切割速度等）的相关规律,以及磨料、材质两大因素的影响。获得了结果对AWJ切割技术的开发和应用具有指导意义和实用价值。     

超高压磨料水射流切割质量的实验研究

对磨料水射流切割断面的形貌特征及其形成机理进行了分析.针对国产AWJ切割系统的特点,实验研究了系统主要参数对几种常用材料切割质量的影响规律.分析了塑性和脆性材料的切割断面特点,为实际的工艺参数选择提供了可靠依据.     

磨料水射流切割铝合金质量模型研究

通过理论研究,分析了磨料水射流去除材料机理及其影响因素。采用正交设计法,进行铝合金切割试验。以切割断面的表面粗糙度值为研究对象,对测得的试验数据进行极差分析。分析结果显示,射流压力、切割速度和磨料流量对切口表面粗糙度的影响较大;靶距和磨料粒子的尺寸对切口表面粗糙度的影响次之。用回归分析方法,建立了磨料水射流切割铝合金材料的表面粗糙度模型。通过试验验证,模型的误差在1.98%~5.14%之间。     

高压水磨料射流切割的力学特性与模型

通过理论分析与实验测定，分析和建立了高压水磨料射流切割的力学特性与模型；得到水射流的流量系数为０．７５，磨料射流的平均流速系数为０．９５；认为水射流主要通过水介质的滞止动压进行切割，磨料射流主要通过磨粒的冲击动压进行切割；给出了射流切断面积速度与材料破坏能量的关系曲线。     

磨料水射流切割质量的参数化模型

作为一种新型的冷态高能束切割技术,磨料水射流(AWJ)以其独特的优点得以广泛应用,但其本身的技术特性使得切割质量存在不足。本文从能量角度分析了AWJ切割质量的影响因素,结合实验数据采用回归分析方法建立了AWJ切割质量与工作压力、切割速度、磨料流量的半经验模型,能够可以满足工程需要。为AWJ切割工艺参数优化选择及切割质量的评价、分析提供了理论基础。     

自激振荡磨料射流原理及切割实验研究

综合前混合式磨料射流与自激振荡水射流的优点,提出了自激振荡磨料射流,并从理论上研究了自激振荡磨料射流喷嘴的结构及工作机理。研究表明,自激振荡磨料射流的最大钻孔速度,切割深度分别比前混合磨料射流提高了４１％和３４％。     

磨料水射流切割钛合金材料的试验研究北大核心CSCD

针对传统工艺对钛合金等难加工材料切割存在诸多弊端的问题,应用磨料水射流(AWJ)技术切割难加工材料可以有效避免工件温度积聚及刀具损伤等,在非淹没条件下对钛合金材料进行切割加工,通过正交试验法对试验结果进行分析,得出水射流压力、靶距及喷嘴移动速度在切割过程中的影响权重,并对3个加工参数进行排序,优化出最佳加工参数组合为A_(3)=280 MPa、C_(1)=10 mm、B_(1)=200 mm/min。试验表明,AWJ技术可显著提高材料的去除率,有利于钻屑的回收利用。对切割过程中的几何因素、动力学特性及材料物理性质进行量纲分析,依据相似第二定律(π定理)建立磨料水射流切割深度与各因素之间的无量纲函数关系式,给出各影响参数的耦合关联性。分析磨料水射流切割钛合金材料最优参数,对磨料水射流技术应用于切割难加工材料有一定的实际意义。     

微磨料气射流切割深度建模

微磨料气射流切割技术具有无热影响区,工件受加工作用力小的优点,非常适合于切割硅和玻璃等硬脆材料薄板.切割深度是评价切割能力的重要参数之一.建立了微磨料气射流切割硬脆材料的切割深度半经验模型.通过全因素实验和回归分析确定了模型中的经验参数.该切割深度模型表明,切割深度随气压和射流角度的增加而增加,随喷嘴横移速度的增加而减小.通过比较实验值和预测曲线,分析了模型的预言能力.结果表明该模型能够有效地预言微磨料气射流切割深度.     

磨料浆体射流切割机床及切割性能研究

将磨料浆体射流技术应用于切割领域，研制出相应的切割机床，避开了国外该项技术中的高压动密封问题，并对该机床的切割性能进行了正交试验，同时，将磨料浆体射流机床与前混合磨料水射流机床的切割性能进行了比较研究,　研究表明，影响磨料浆体射流切割性能的主要因素依次是切割速度、切割压力和靶距；在相同切割条件下，磨料浆体射流机床与前混合磨料水射流机床的切割力大致相同，但磨料浆体射流机床的切割质量明显好于后者，切割能耗大大低于后者。     

An access detection and machine cycle tracking system for machine safety

Abrasive water jet (AWJ) machining is characterized by its versatility, i.e., it can be applied to a wide variety of materials. Currently, one important application is for manufacturing gem artifacts, especially agate, which is the largest gemological material produced in the state of Rio Grande do Sul. However, one of the main obstacles to its popularization is the cost associated with the process, due to the high abrasive consumption required for a good quality surface finish. In this sense, this research paper presents a study of the influence of the main process parameters (traverse speed and abrasive mass flow rate) on the surface finish of agates machined by AWJ. The experimental procedure used three different traverse speeds, four abrasive mass flow rate in two different thicknesses of agate’s plates. Surface roughness and angle of striation marks were observed for different depths from the jet entrance surface. Results were analyzed using analysis of variance (ANOVA). Through the study, it was found that the machined surface finish varies according to the depth from the entrance surface of the abrasive jet. Also, it was concluded that the surface finish of the machined surface by AWJ (surface roughness and striation marks) of the agate’s plates machined by AWJ exhibits similar results for both thicknesses tested. ANOVA showed that the traverse speed is more significant than abrasive mass flow rate for the material studied with respect to the surface finish. Thus, for a small material thickness, it is possible to use high traverse speed and low abrasive mass flow rate which makes the process more economical.     

磨料水射流切割陶瓷材料的加工表面质量研究

对磨料水射流切割氧化铝陶瓷的加工表面质量进行了试验研究,对磨料水射流切割陶瓷的切口结构形状进行了论述与分析,并分析了工艺参数对加工表面质量的影响。结果表明切口断面从上往下很明显地分成三部分:光滑区、波纹区和破碎区,光滑区的加工表面粗糙度随着水压力的增加、喷嘴横移速度和磨料粒度的减小而减小;靶距增加,表面粗糙度先减小,后增加。     

The effect of particle hardness and shape when abrasive water jet milling titanium alloy Ti6Al4V

Legislative restriction on effluent disposal has resulted in an increase in the environmental costs of chemical milling and replacement methods are being sought. Abrasive water jet cutting (AWJ) is a mature process that is employed to through cut materials that are difficult to process by more conventional methods and the process is also being developed for controlled depth milling (CDM) to produce three-dimensional features which in the past might have been produced by chemical or etching processes. A major problem to be solved when using AWJ as a CDM technique is that of tolerance on depth, surface waviness and surface roughness of the milled area. In the current work, the effects of milling parameters on the surface characteristics are investigated when milling a titanium alloy (Ti6Al4V) with different abrasives, namely white and brown aluminium oxide, garnet, glass beads and steel shot. It has been demonstrated that the ratio between the hardness of the workpiece and the abrasive is more important than particle shape. Material removal rate and surface roughness increased when particle hardness is increased. Shape factor and particle hardness have no significant effect on surface waviness. For the abrasives investigated; traverse speed is shown to govern the operative mechanism of material removal and thus the material removal rate. It is also shown that the surface waviness can be reduced as the traverse speed is increased whilst, the surface roughness is not strongly dependent on traverse speed.     

PENETRATION ABILITY OF ABRASIVE WATERJETS IN CUTTING OF ALUMINUM-SILICON CARBIDE PARTICULATE METAL MATRIX COMPOSITES

This article presents a set of studies performed on aluminum-silicon carbide particulate metal matrix composites prepared by adding 5, 10, 15 and 20% of SiC in aluminum alloy and processed with abrasive water jets that are formed with garnet and silicon carbide abrasives of 80 mesh size. These studies are essentially meant to assess the penetration ability of abrasive water jets on different compositions of Al-SiC _p MMCs produced by stir casting method. Abrasive waterjet cutting experiments were conducted on trapezoidal shaped specimens of different composites as well on the constituent materials i.e., 100% aluminum alloy and 100% SiC specimens by varying water pressure, jet traverse speed and abrasive mass flow rate, each at three different levels. The percentage contribution of individual and combined effects of process parameters on penetration ability was analyzed by means of analysis of variance. Contribution of waterjet pressure and traverse speed on jet penetration in these meaterials are found to be more than abrasive flow rate. Among the interaction effects, waterjet pressure and jet traverse speed combinations contribute more to jet penetration. The results presented in this study can be used to build statistical models that can predict the depth of penetration of jet in different MMCs. This study also highlights the need to choose suitable abrasive mass flow rates and jet traverse speeds for effective processing of MMCs with abrasive water jets.     

Monitoring of abrasive water jet (AWJ) cutting using sound detection

Our main objective in the present work is to develop a methodology and create a system for the abrasive water jet (AWJ) machining process control. In the case of AWJ cutting, besides the cutting head traverse rate, the distance between the mixing tube and the workpiece, designated as the stand-off distance, has a predominant influence on the workpiece quality. The control of the traverse rate is performed by the machine controller. The stand off-distance control during the machining represents a problem because no effective on-line in real-time stand-off distance detection system has been developed yet. The detection of the stand-off distance during cutting enables better AWJ machining process control. order to monitor the stand-off distance, we measure the emitted sound generated during the AWJ straight cut operation and analyse its characteristic attributes. In order to verify the proposed stand-off distance monitoring methods, a set of experiments was carried out. The signal analysis was performed in both time and frequency domain. The obtained results show an evident influence of the stand-off distance on sound emission. Thus, efficient control of the AWJ cutting process through sound detection appears to be viable.     

磨料水射流切割石材加工表面质量的试验研究

文中对高压磨料水射流切割石材的加工表面质量进行了试验研究,分析了水射流压力、靶距、切割速度和磨料流量对加工表面质量的影响。结果表明:当水射流压力增大时,光滑区切割深度增大,而表面粗糙度先减小后增大;当靶距增加时,表面粗糙度增大,而切割光滑区切割深度减小;当切割速度增加时,表面粗糙度增大,而光滑区切割深度迅速减小;当磨料流量增加时,表面粗糙度减小,而切割表面的光滑区深度先增大后减小。     

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.     

An Experimental Study to Enhance the Cutting Performance in Abrasive Waterjet Machining

An experimental study to enhance the cutting performance in abrasive waterjet (AWJ) machining is presented. The study uses the techniques of jet forward impact angles and multipass operations both individually and concurrently when cutting an alumina ceramic and a polymer matrix composite. A brief report on the effect of jet impact angle in single pass cutting is made first, which shows that the optimum jet impact angle for both the ceramics and polymer matrix composite is about 80°. It is found that the multipass cutting technique can increase the cutting capability and application domain of AWJ cutting. It can also improve the major cutting performance such as the depth of cut as compared to single pass cutting within the same total cutting time. The benefit of using multipass cutting operations is further enhanced when it is combined with a jet forward angle of 80° in cutting alumina ceramics.