磨料水射流切割技术

本文列举了作者应用自行设计的前混合式磨料水射流切割试验装置完成的切割试验，分析了磨料水射流切割金属材料的原理及该项技术的切割优点，认为磨料水射流切割是很有发展前途的冷加工新工艺，可作为一种新的特种加工工艺加以推广。     

微细磨料水射流切割技术的研究进展

产品小型化和加工过程微型化是现代制造加工业的发展趋势,为适应微器件的精加工,在常规磨料水射流切割技术基础上,微细磨料水射流切割技术逐渐改进和发展起来了。微细磨料水射流直径在1~100 μm之间,比常规磨料水射流直径(500~1200 μm)小一个数量级,其割缝宽度、表面质量已达到激光切割的加工水平。微细磨料水射流特别适合对金属、陶瓷、半导体以及高分子聚合物等难加工的硬脆材料进行微细加工,是一种具有广阔应用前景的全新微型加工技术。为了解该项技术的最新发展情况,该文介绍了微细磨料水射流的特点、射流的生成方式及切割机理,以及影响切割性能的主要参数和部分工业应用实例,最后提出了微细磨料水射流切割技术有待深入研究的问题和今后的发展趋势。     

基于稳健性设计的磨料水射流参数优化

磨料水射流加工技术是非传统的加工技术,它依靠高压、高水速和高速砂粒磨料作用在工件上去除材料,而在磨料水射流切割加工过程中存在切割深度和表面粗糙度较难控制的问题。基于稳健性设计理论、变量分析和信噪比,利用L9正交试验,对磨料水射流的压力、磨料流量、靶距和磨料粒径等加工过程参数进行优化。分析了加工参数的影响优先级,得出了磨料水射流加工参数的最优值,建立了切割深度信噪比回归模型并通过检验证明模型可靠。稳健性设计前后结果对比表明,切割深度和表面粗糙度比优化前有明显提升,从而提升了磨料水射流的加工质量。在实际加工不锈钢304中验证了结果的可靠性和该方法的可行性,为磨料水射流加工技术的推广提供了指导。     

磨料水射流切割与激光切割,等离子切割的比较分析

根据大量实验研究结果，对磨料水射流切割与激光，等离子切割进行综合比较分析。阐明了磨料水射流对板材切割的适应性，合理性和经济性。     

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。     

磨料水射流切割机制研究进展

从单个磨料颗粒造成的冲蚀入手,综述了磨料水射流切割机制的研究进展,介绍了磨料射流切割过程中的微观切割模型、微观机制的扫描电镜分析结果,被切割材料的内部应力分析,水射流的水楔效应和跃迁速度以及材料切割的宏观分析结果.提出今后对磨料水射流切割机制的研究应从数值模拟研究、专家系统和模糊理论的应用、空化切割机制以及液相-颗粒薄层的阻尼效应等方面入手.     

磨料水射流二次逆向切割对断面质量的提升研究

针对磨料水射流切割过程中存在的拖尾余纹、切缝锥度和切割留尾问题，基于磨料水射流切割理论，设计了3组不同因素组合下的单次正向切割、单次1/2速度正向切割和二次逆向切割试验，探讨了3种不同切割方式下的断面形貌产生机理，并对试验结果进行对比分析。结果表明，二次逆向切割可降低表面粗糙度约52%~85%，可降低切缝锥度约66%~72%，同时可消除切割留尾。因此，高压磨料水射流采用二次逆向切割的方式可以显著提高磨料水射流切割工件的断面质量。     

磨料水射流切割技术及其应用

阐述了磨料水射流的切割原理及低压磨料水射流切割机的工作原理和主要构造。并详细论述了低压磨料水射流切害虫机具有结构简单、操作方便、切缝质量好、切割效率高,并能对复杂图形实现智能化切守旧等优点,它是切割玻璃、陶瓷、大理石及花岗石等难切割材料的理想设备。     

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。     

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.     

ENHANCING THE DEPTH OF CUT IN ABRASIVE WATERJET CUTTING OF ALUMINA CERAMICS BY USING MULTIPASS CUTTING WITH NOZZLE OSCILLATION

An experimental investigation is presented to increase the depth of cut in abrasive waterjet (AWJ) cutting of alumina ceramics by introducing a new cutting technique combining multipass operations with controlled nozzle oscillation. Plausible trends of the depth of cut per pass and total depth of cut with respect to the number of passes and the parameters in each pass are discussed. It shows that cutting with nozzle oscillation can significantly increase the depth of cut in the single-pass cutting mode, while further gains in the depth of cut can be made by using multipass cutting with nozzle oscillation. While multipass cutting can be used to increase the total depth of cut for machining thicker materials, it has been found that an average increase of 50.8% in the total depth of cut can be expected by using multipass cutting with nozzle oscillation as compared to single-pass cutting without nozzle oscillation within the same cutting time. Recommendations are finally made as a practical guide for the selection of process parameters in multipass AWJ cutting of alumina ceramics with controlled nozzle oscillation.     

Topography and microstructure of the cutting surface machined with abrasive waterjet

Abrasive waterjet (AWJ) technology has been widely used for cutting materials in precision machining. The present paper reports the surface topography and microstructure of the cutting surfaces machined by AWJ. Four different kinds of ductile metallic materials were used for preparation of specimens. With the AWJ processing technique, smooth surfaces were easily obtained with a lower surface roughness about 2 to 3 μm. By comparing the microhardness of the specimens with the control surface sample obtained by wire electrodischarge machining, it is found that there is no heat-affected zone on the cutting surfaces machined by AWJ. By observing the surface morphology and microstructure, the features of friction and wear marks are revealed. The results show that a smooth cutting surface is more easily obtained on hard materials, while erosions on soft material surfaces are more serious. All scratches have a clear consistent direction, under the action of mechanical abrasive wear.     

异种材料清理实用技术—高压水射流应用

高压水射流具有选择切割和冷加工的独特优点,具有较高的切除能力和效率,并且不改变加工件物理结构和化学成分,是一种十分典型的绿色制造技术,使得它在异种材料的剥离去除或清理工作中独显优势而得到越来越多的应用,通过对注塑螺杆清理的实际应用研究与试验表明高压水射流将在未来的绿色制造和生产中扮演重要角色。     

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。     

基于人工神经网络的磨料水射流切割加工模型

作为一种冷态加工新工艺 ,磨料水射流 (AWJ)以其独特的优点得到广泛应用 ,但由于高速液固两相流本身的特性 ,AWJ切割加工是一个受多参数影响的复杂随机过程 ,很难建立一个适当的机理模型。基于人工神经网络理论 ,本文建立了切割厚度与主要工艺参数间的AWJ切割加工预测模型 ,模型预测结果与实验值及Zeng的经验模型进行了比较 ,该网络模型能可靠、准确地映射出AWJ的加工规律 ,可应用于AWJ切割加工过程的参数优化选择、加工规律计算机仿真及智能化控制中。     

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.     

磨料水射流切割工艺参数的实验研究

磨料水射流切割中影响切割深度的因素很多,各工艺参数的选择和合理搭配对切割结果有很大影响,并且难以用精确的数学模型来描述.以磨料水射流切割混凝土为例,考察了射流压力、进给速度、靶距、磨料流量、磨料粒径和材料性能等工艺参数对最大切割深度的影响.结果表明:(1)切割深度与射流压力呈线性增长关系;(2)在一定范围内切割深度随磨料流量增加而增加,但当磨料流量达到一定值后,切割深度随流量增加反而下降;(3)切割深度随磨料粒径的增加呈先增加后减小的规律,存在一极值点;(4)切割深度随切割速度的增加呈指数衰减;(5)存在一最佳靶距,超过这个界限值时,随着靶距的增大,切割深度急剧减小;(6)混凝土试件抗压强度的抗压强度越大,切割深度越小.     

Optimization of abrasive waterjet machining using multi-objective cuckoo search algorithm

Abrasive waterjet (AWJ) machining is widely applied in the fields of civil and mechanical engineering. In this study, a general and theoretical analysis procedure was presented before computing application. It mainly focused on the kinetic energy model and wear rate model in machining process. Then, the multi-objective cuckoo algorithm was employed for optimization design of AWJ cutting head model, making sure to maximize the output energy and minimize the nozzle erosion rate while keeping the other factors constant. To demonstrate the effectiveness of the above strategy, a practical AWJ machining system was selected for investigation purpose. The proposed model was compared with experimental data for investigating the difference between the initial design and the optimized model. The results showed that the multi-objective cuckoo algorithm has great ability in prediction of outlet power and wear rate. Meanwhile, the optimized parameters were also superior to the original design, compared with experimental test data. The developed model can be used as a systematic approach for prediction in an advanced manufacturing process.     

Radial-mode abrasive waterjet turning of short carbon–fiber-reinforced plastics

An experimental study is carried out for single-pass radial-mode abrasive waterjet (AWJ) turning of a short carbon–fiber-reinforced polyetheretherketone (PEEK) specimen to understand the machining process and the effects of major process variables (feed speed, water pressure, abrasive mass flow rate, nozzle tilt angle, and rotational surface speed) on the major machining performance measures, that is, the depth of cut, material removal rate (MRR) and surface roughness. It is found that high water pressure, normal nozzle impact angle and high rotational speed with suitably selected feed speed and abrasive flow rate may be selected to achieve a high MRR without significantly compromising the surface roughness. Mathematical models for the three cutting performance measures are then developed for use in process control.