Abstract Abrasive Water Jet Machining Research Articles

Pocket Milling of AISI 1045 Steel using Abrasive Water Jet Machining by Varying Contours

Abrasive water jet machining (AWJM) is an innovative machining technology recognized for cutting tougher materials smoothly. This study investigates the significance of AWJM parameters on surface roughness (SR) and material removal rate (MRR); while machining AISI1045medium carbon steel. Pocket milling has been done on the material; pockets of definite size/specifications are machined and associated MRR and SR are investigated. The Input parameters considered are Standoff distance (SOD), Cutting feed, Pressure. Experimental parameters are analyzed as per Taguchi method (DOE). The interaction effects of input process parameters are studied through 3D contour plots. ANOVA is used to determine the influencing parameter, and it has been verified that the ideal combination of Taguchi process parameters satisfies the actual machining of material.

Visualization and evaluation of the spatial kinematic rotation error of a five-axis abrasive water jet cutting head

Abrasive water jet (AWJ) technology has been more and more used in space curved surface machining. Dynamic angle compensation technology based on the five-axis linkage control system was the core to eradicate the errors caused by taper and jet lag in AWJ machining and enabled this technology to get into some precision fields. But the spatial kinematic rotation error of the cutting head in five-axis AWJ machine tool which has a direct impact on AWJ machining performance and accuracy has not been systematically studied. Aimed at this, this paper explored a new method based on spatial meshes to obtain the spatial kinematic rotation error of the cutting head. According to the visualization of the experimental data, the spatial kinematic rotation error was found with no obvious pattern. Then, a dimension reduction method was employed to mining these data and enabled this irregular error to be predicted with mapping method. According to the verification experiments, this new method was proved efficiently and useful in predicting the spatial kinematic rotation error.

Titanium Alloy Milling Using Abrasive Water Jet for Repair Application: Modifications in Surface Quality and Material Integrity Following Plain Water Jet Cleaning

Abrasive Water Jet (AWJ) machining has proven to be an effective and versatile technique for milling various kinds of materials, even with low machinability such as aerospace grade titanium alloy Ti6Al4V. Many studies have been performed in order to master this technology and produce geometrically accurate shapes. However, in the context of bonding repairs which require surfaces free from foreign bodies, AWJ machining presents a significant drawback in form of abrasive grit embedment. The goal of this present work is then to investigate the effect of a post-AWJ machining cleaning operation using Plain Water Jet process (PWJ – i.e. without abrasive particles) on the surface quality and material properties. For this, several characterization techniques were employed. It was concluded that the contamination has been reduced by 65% without noticeable changes in depth of cut and crater volume. The AWJ milling operation produced surface and subsurface hardening as well as biaxial compressive residual stress, mostly piloted by the jet pressure. PWJ cleaning reduced the depth of hardening without clear modification in surface hardness.

Machinability and Delamination Studies on Glass Fiber Reinforced Polymer Matrix Composite Cut by Abrasive Water Jet Machine

Abrasive water jet machining possesses inherent technological and manufacturing advantages unmatched by most machine tools. They are generally used in automotive, marine and aerospace industries for machining of composites. However, abrasive water jet cutting of GFRP laminates possesses several challenges, such as surface finish and delamination of the cutspecimen. Henceforth, more experimental work is needed to provide sufficient machinability databases for manufacturing industries. This paper presents an experimental study for cutting GFRP laminates. Different AWJM conditions including pressure, traverse speed and abrasive flow rate are analyzed using full factorial design of experiments. Machining process responses such as surface roughness (Ra), top and bottom kerf width, kerf taper, delamination of fibers have been evaluated using analysis of variance (ANOVA) technique. The optimum process parameters for AWJM of glass fiber reinforced polymers have beensuggested.

NEW CHALLENGES IN ABRASIVE WATER JET MACHINING

Abrasive water jet machining (AWJM) is one of the most important method used in cutting different types of materials: alloy sheet, marble, glass, rocks. This process is used in the aeronautic, automotive, metallurgy industries and even in some art techniques and textile industry. The method consists in transforming the kinetic energy of a solid particle directed with water jet at a high pressure to remove material through erosion and abrasion. AWJM is low cost equipment compared to other conventional cutting technologies. This paper is an attempt to review the achievements made in AWJM technology for different hardness materials.

A New Look into the Loose Particle Impact Process for Ductile Materials

Abrasive waterjet machining involves the impact of micro-particles at high or ultrahigh velocities. The material removal mechanism for ductile materials has been popularly accepted for over a half century as cutting wear and deformation wear caused by the component of impact force parallel and perpendicular to the target surface respectively. However, this definition of erosion mechanisms does not give an insight into the erosion process, but describes a surface phenomenon of the event. A computational study has been undertaken to reveal the underlying mechanisms of the material removal process. Based on the findings, the impact erosion mechanisms are re-defined as material destruction through (a) failures induced by inertia, (b) failure induced by elongation, and (c) failure induced by adiabatic shear bending. This new definition appears to better represent the physical process of material deformation and removal by loose micro-particle impacts at high and ultrahigh velocities.

An Experimental Study of Influence of Process Parameters on Kerf Properties of Abrasive Water Jet Machined Carbon Fibre Reinforced Polymer

Abrasive water jet machining is an emerging technology for composite material processing. The machining of carbon fibre reinforced polymer by conventional means is difficult due to excessive tool wear, delamination and improper kerf properties. This paper presents experimental study of influence of process parameters on kerf top width of abrasive water jet machined carbon fibre reinforced polymer. The process parameters namely water pressure, stand-off distance, traverse rate, and abrasive mass flow rate are considered in the present work. Taguchi's design of experiment and analysis of variance are used to investigate the effect of process parameters on kerf top width. It is observed that stand-off distance and traverse rate are most significant parameters in influencing the kerf top width. A set of optimum process parameters is identified on the basis of analysis of the experimental data. A regression model is developed using multi-linear regression approach on the basis of experimental analysis. Results of the present work are successfully compared with the published literature.

A Study on Ultrasonic Torsional Vibration-Assisted Abrasive Waterjet Polishing of Ceramic Materials

Abrasive waterjet machining is considered as a promising technique in hard-brittle material polishing. In this paper, The ultrasonic torsional vibration is considered to apply on the workpiece to improve the abrasive waterjet polishing quality and efficiency. The process parameters in the ultrasonic torsional vibration-assisted abrasive waterjet polishing are optimized. The ultrasonic torsional vibration in the role of the abrasive waterjet polishing is investigated. The results show that the application of ultrasonic torsional vibration can effect of abrasive particle movement and increase the critical depth of the ceramic materials.

An experimental investigation on cutting performance of abrasive water jet machining of austenite steel (AISI 316L)

Abrasive water jet machining (AWJM) has proven to be an effective technology for processing variety of engineering materials. In this study, research work involved in experimental investigation on cutting performance of AWJM of austenite steel (AISI 316L) is described. AWJM process is characterised by a number of process parameters that affects the quality of machining. In the present work, influence of three parameters, namely pressure, traverse rate and stand-off distance on surface finish of austenite steel (AISI 316L) is investigated. Full factorial experimental design is applied for experimentation. Analysis of variance is performed and an empirical model is developed by multilinear regression analysis for surface roughness. After experimental analysis, conformation test is done. The results obtained in the present work are compared successfully with the published literature.

An SPH Simulation on Vibration Assisted Abrasive Erosion of Hard Brittle Material in Abrasive Waterjet Machining

Abrasive waterjet machining (AWJ) is one of the fastest growing non-conventional machining methods. However, low pressure and fine abrasive implemented in AWJ precision machining for reducing the surface damage reduce the efficiency. Therefore ultrasonic vibration is considered to apply on the workpiece to improve the machining efficiency. In order to analyze the effect of the vibration on erosion in AWJ machining, smoothed particle hydrodynamics (SPH) is used to simulate the erosion process for avoiding the mesh distortion in finite element method (FEM) when simulating large deformation and high strain rate problems. The results show that the application of ultrasonic vibration can effectively improve the erosion rate due to the dynamics variation of the erosion process.

An Experimental Research on Abrasive Water Jet Polishing of the Hard Brittle Ceramics

Abrasive water jet (AWJ) technology, due to its potential advantages, is a promising machining method for precision machining brittle materials. In this research, the AlN ceramics was polished using an AWJ machining system. A considerable processing quality has been achieved and a reduction up to 62% of the surface roughness has been obtained. Effects of different process parameters on the surface roughness of the polished workpiece were analyzed. Under the current conditions of the experiments, using a lower impact angle, smaller abrasives and a lower nozzle traverse speed may be appropriate for polishing AlN ceramics.

Capability of Advanced Abrasive Waterjet Machining and its Applications

Abrasive waterjet machining has been recently considered as a promising, emerging non-conventional technology with an extensive growth in its market share and research activities. In this paper, a Europe’s first 5-axis AWJ system established at the University of Nottingham will be introduced followed by some of the research works explored on the capability of AWJ machining (e.g. AWJ cutting, AWJ drilling, AWJ milling, AWJ turning) on exotic materials such as Ti-based alloys at different niche applications. Thanks to advances in the complementary AWJ technology (e.g. ultra-high pressurized pump) and advanced machine designs (e.g. multi-axis machine movement), it was found that the machining capability of abrasive waterjet (even plain waterjet) can be extended if innovative strategies are applied.