scholarly journals Abrasive Waterjet (AWJ) Forces—Potential Indicators of Machining Quality

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3309
Author(s):  
Libor M. Hlaváč ◽  
Massimiliano P. G. Annoni ◽  
Irena M. Hlaváčová ◽  
Francesco Arleo ◽  
Francesco Viganò ◽  
...  
Keyword(s):  
Traverse Speed ◽  
Abrasive Waterjet ◽  
Speed Ratio ◽  
Machining Processes ◽  
Measuring Device ◽  
Cutting Head ◽  
Wear Ratio ◽  
Tilting Angle ◽  
Declination Angle ◽  
Awj Cutting

The necessity of monitoring the abrasive waterjet (AWJ) processes increases with the spreading of this tool into the machining processes. The forces produced on the workpiece during the abrasive waterjet machining can yield some valuable information. Therefore, a special waterjet-force measuring device designed and produced in the past has been used for the presented research. It was tested during the AWJ cutting processes, because they are the most common and the best described up-to-date AWJ applications. Deep studies of both the cutting process and the respective force signals led to the decision that the most appropriate indication factor is the tangential-to-normal force ratio (TNR). Three theorems concerning the TNR were formulated and investigated. The first theorem states that the TNR strongly depends on the actual-to-limit traverse speed ratio. The second theorem claims that the TNR relates to the cutting-to-deformation wear ratio inside the kerf. The third theorem states that the TNR value changes when the cutting head and the respective jet axis are tilted so that a part of the jet velocity vector projects into the traverse speed direction. It is assumed that the cutting-to-deformation wear ratio increases in a certain range of tilting angles of the cutting head. This theorem is supported by measured data and can be utilized in practice for the development of a new method for the monitoring of the abrasive waterjet cutting operations. Comparing the tilted and the non-tilted jet, we detected the increase of the TNR average value from 1.28 ± 0.16 (determined for the declination angle 20° and the respective tilting angle 10°) up to 2.02 ± 0.25 (for the declination angle 30° and the respective tilting angle of 15°). This finding supports the previously predicted and published assumptions that the tilting of the cutting head enables an increase of the cutting wear mode inside the forming kerf, making the process more efficient.

scholarly journals Abrasive Waterjet (AWJ) Forces—Indicator of Cutting System Malfunction

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1683
Author(s):  
Libor M. Hlaváč ◽  
Damian Bańkowski ◽  
Daniel Krajcarz ◽  
Adam Štefek ◽  
Martin Tyč ◽  
...  
Keyword(s):  
Online Monitoring ◽  
Force Measurement ◽  
Traverse Speed ◽  
Cutting Process ◽  
Abrasive Waterjet ◽  
Continuous Control ◽  
Measuring Device ◽  
Force Ratio ◽  
Deformation Force ◽  
Awj Cutting

Measurements enabling the online monitoring of the abrasive waterjet (AWJ) cutting process are still under development. This paper presents an experimental method which can be applicable for the evaluation of the AWJ cutting quality through the measurement of forces during the cutting process. The force measuring device developed and patented by our team has been used for measurement on several metal materials. The results show the dependence of the cutting to deformation force ratio on the relative traverse speed. Thus, the force data may help with a better understanding the interaction between the abrasive jet and the material, simultaneously impacting the improvement of both the theoretical and empirical models. The advanced models could substantially improve the selection of suitable parameters for AWJ cutting, milling or turning with the desired quality of product at the end of the process. Nevertheless, it is also presented that force measurements may detect some undesired effects, e.g., not fully penetrated material and/or some product distortions. In the case of a proper designing of the measuring device, the force measurement can be applied in the online monitoring of the cutting process and its continuous control.

scholarly journals Experimental Analysis and Soft Computing Modeling of Abrasive Waterjet Milling of Steel Workpieces

2020 ◽  
Vol 318 ◽  
pp. 01031
Author(s):  
Panagiotis Karmiris-Obratański ◽  
Nikolaos E. Karkalos ◽  
Anastasios Tzotzis ◽  
Panagiotis Kyratsis ◽  
Angelos P. Markopoulos
Keyword(s):  
Soft Computing ◽  
Process Parameters ◽  
High Efficiency ◽  
Traverse Speed ◽  
Abrasive Waterjet ◽  
Machining Processes ◽  
Metalworking Industry ◽  
Complex Features ◽  
Alternative Processes ◽  
Conventional Machining

Conventional machining processes such as turning, milling and drilling have long been prominent in the metalworking industry but alternative processes which do not require the use of a cutting tool in order to conduct material removal have also been proven to be sufficiently capable of achieving high efficiency in various cases. In particular, Abrasive Waterjet (AWJ) machining can be regarded as a rather appropriate choice for cutting operations, taking into consideration that it involves no heat affected zones, is able to process all material types and create a variety of complex features with success. In the present work, a comprehensive study on the effect of four process parameters, namely jet traverse speed, stand-off distance, abrasive mass flow rate and jet pressure on the width and depth of machined slots on a steel workpiece is conducted. The results are first analyzed with statistical methods in order to determine the effect and the relative importance of each parameter on the produced width and depth of the slots. Finally, these results are used to develop soft computing predictive models based on Artificial Neural Networks (ANN), which can efficiently relate the process parameters with its outcome.

Development of ice abrasive waterjet cutting technology

2017 ◽  
Vol 2 (81) ◽  
pp. 76-84
Author(s):  
J. Valentinčič ◽  
A. Lebar ◽  
I. Sabotin ◽  
P. Drešar ◽  
M. Jerman
Keyword(s):  
High Speed ◽  
Power Plants ◽  
Water Jet ◽  
Abrasive Waterjet ◽  
Abrasive Water Jet ◽  
Influence Of Process Parameters ◽  
Cutting Head ◽  
Ice Particles ◽  
Main Challenge ◽  
Awj Cutting

Purpose: Abrasive water jet (AWJ) cutting uses mineral abrasive to cut practically all materials. In ice abrasive water jet (IAWJ) cutting, the ice particles are used as abrasive. IAWJ is under development with the aim to bridge the gap in productivity between the abrasive water jet (AWJ) and water jet (WJ) cutting. It is clean and environmentally friendlier in comparison with AWJ, while its cutting efficiency could be better than WJ. Design/methodology/approach: The main challenge is to provide very cold and thus hard ice particles in the cutting zone, thus cooling the water under high pressure is utilized. Further on, two approaches to obtain ice particles in the water are studied, namely generation of ice particles in the cutting head and generation of ice particles outside of the cutting head and adding them to the jet similar as in AWJ technology. In this process it is essential to monitor and control the temperature occurring in the system. Findings: To have ice particles with suitable mechanical properties in the cutting process, the water have to be precooled, ice particles generated outside the cutting head and later added to the jet. The results show that, contrary to the common believe, the water temperature is not significantly changed when passing through the water nozzle. Research limitations/implications: The presence of ice particles was only indirectly identified. In the future, a special high speed camera will be used to study the influence of process parameters on ice particle distribution. Practical implications: IAWJ technology produces much less sludge (waste abrasive and removed workpiece material mixed with water) than AWJ technology which is beneficial in e.g. disintegration of nuclear power plants. IAWJ technology has also great potential in the food and medical industries for applications, where bacteria growth is not desired. Originality/value: The paper presents the latest achievements of IAWJ technology.

scholarly journals Impact of Preparation of Titanium Alloys on Their Abrasive Water Jet Machining

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7768
Author(s):  
Adam Štefek ◽  
Martin Tyč
Keyword(s):  
Titanium Alloys ◽  
Niti Alloy ◽  
Traverse Speed ◽  
Structural Features ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Abrasive Water Jet Machining ◽  
Declination Angle ◽  
The Impact ◽  
Awj Cutting

Several titanium alloys, i.e., grade 2 Ti, Ti6Al4V and NiTi alloy, prepared by selected deformation procedures were subjected to abrasive water jet (AWJ) cutting and subsequently analysed. The study describes samples’ preparations and respective material structures. The impact of deformation processing of the selected alloys on the declination angle during cutting, and the results of measurements of surface wall quality performed for the selected samples at the Department of Physics of Faculty of Electrical Engineering and Computer Science at VŠB–Technical University of Ostrava, are presented and discussed, as are also the influences of structural features of the processed titanium alloys on surface qualities of the investigated samples. The results showed that the highest resistance to AWJ machining exhibited the Ti6Al4V alloy prepared by forward extrusion. Its declination angle (recalculated to the thickness 10 mm to compare all the studied samples) was 12.33° at the traverse speed of 100 mm/min, pumping pressure of 380 MPa, and abrasive mass flow rate of 250 g/min.

EXPERIMENTAL INVESTIGATION ON ABRASIVE WATERJET MACHINING OF FIBRE VINYL ESTER COMPOSITE

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Puneet Kumar ◽  
Bhavik Tank ◽  
Ravi Kant
Keyword(s):  
Surface Roughness ◽  
Vinyl Ester ◽  
Water Pressure ◽  
Traverse Speed ◽  
Abrasive Waterjet ◽  
Machining Processes ◽  
Significant Parameter ◽  
Abrasive Water Jet Machining ◽  
Abrasive Waterjet Machining ◽  
Waterjet Machining

Abrasive water jet machining (AWJM) is one of the most developed non-traditional machining processes. It is generally used to cut difficult to cut materials like composites. The present study is focused on machining of carbon fiber vinyl ester composite with AWJM. The effect of process parameters namely water pressure, standoff distance and traverse speed on surface roughness and kerf tapper is studied. Design of experiment is done by using Taguchi L16 orthogonal array. It is observed that water pressure is the most significant parameter followed by traverse speed. It is found that with the increase in water pressure and decrease in traverse speed of AWJM, surface roughness and kerf tapper of machined samples decreases.

Surface Waviness in Abrasive Waterjet Offset-Mode Turning

2014 ◽  
Vol 599-601 ◽  
pp. 555-559
Author(s):  
Iman Zohourkari ◽  
Mehdi Zohoor ◽  
Massimiliano Annoni
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Water Pressure ◽  
Traverse Speed ◽  
Abrasive Waterjet ◽  
Depth Of Cut ◽  
Surface Waviness ◽  
Cutting Head

In this paper, surface waviness quality in abrasive waterjet offset-mode turning has been studied regarding variations of some process parameters. Influence of five main operational parameters such as water pressure, cutting head traverse speed, abrasive mass flow rate, workpiece rotational speed and depth of cut on surface waviness of turned parts have been investigated using statistical approach. Second order regression model presented for surface waviness. The model accuracy was verified by comparing with experimental data. It found that abrasive mass flow rate, cutting head traverse speed and DOC are the most influential parameters while water pressure and workpiece rotational speed show lesser effectiveness.

Modeling of Surface Waviness in Abrasive Waterjet Offset-Mode Turning

2014 ◽  
Vol 621 ◽  
pp. 202-207
Author(s):  
Iman Zohourkari ◽  
Mehdi Zohoor ◽  
Massimiliano Annoni
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Water Pressure ◽  
Traverse Speed ◽  
Abrasive Waterjet ◽  
Depth Of Cut ◽  
Surface Waviness ◽  
Cutting Head

In this paper, surface waviness produced by turning aluminum parts with abrasive waterjet has been studied regarding changes in some process parameters. Effect of five major parameters such as water pressure, cutting head traverse speed, abrasive mass flow rate, workpiece rotational speed and depth of cut have been investigated using analysis of variances. Second order regression model presented forwaviness.The validity of the model wasconfirmed bycomparing with experimental data. It found thatabrasive mass flow rate, cutting head traverse speed and DOC are the most influencing parameters while water pressure and workpiece rotational speed show lesser effectiveness.

scholarly journals Effect of Waterjet Machining Parameters on the Cut Quality of PP and PVC-U Materials Coated with Polyurethane and Acrylate Coatings

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7542
Author(s):  
Miroslav Müller ◽  
Viktor Kolář ◽  
Jan Šulc ◽  
Rajesh Kumar Mishra ◽  
Monika Hromasová ◽  
...  
Keyword(s):  
Base Material ◽  
Polymeric Materials ◽  
Traverse Speed ◽  
Sem Analysis ◽  
Kerf Width ◽  
Abrasive Waterjet ◽  
Machining Parameters ◽  
Taper Angle ◽  
Cutting Head ◽  
Cut Quality

The article focuses on the machining of polymeric materials polypropylene (PP) and un-plasticized poly vinyl chloride (PVC-U) after surface treatment with polyurethane and acrylate coatings using waterjet technology. Two types of waterjet technologies, abrasive waterjet (AWJ) and waterjet without abrasive (WJ), were used. The kerf width and its taper angle, at the inlet and outlet of the waterjet from the workpiece, were evaluated. Significant differences between AWJ and WJ technology were found. WJ technology proved to be less effective due to the creation of a nonuniform cutting gap and significant burrs. AWJ technology was shown to be more efficient, i.e., more uniform cuts were achieved compared to WJ technology, especially at a cutting head traverse speed of 50 mm·min−1. The most uniform kerf width or taper angle was achieved for PP + MOBIHEL (0.09°). The materials (PP and PVC-U) with the POLURAN coating had higher values of the taper angle of the cutting gap than the material with the MOBIHEL coating at all cutting head traverse speeds. The SEM results showed that the inappropriate cutting head traverse speed and the associated WJ technology resulted in significant destruction of the material to be cut on the underside of the cut. Delamination of the POLURAN and MOBIHEL coatings from the base material PP and PVC-U was not demonstrated by SEM analysis over the range of cutting head traverse speeds, i.e., 50 to 1000 mm·min−1.

scholarly journals Investigation of the Effects of Machining Parameters on Material Removal Rate in Abrasive Waterjet Turning

2014 ◽  
Vol 6 ◽  
pp. 624203 ◽  
Author(s):  
Iman Zohourkari ◽  
Mehdi Zohoor ◽  
Massimiliano Annoni
Keyword(s):  
Flow Rate ◽  
Material Removal Rate ◽  
Rotational Speed ◽  
Material Removal ◽  
Removal Rate ◽  
Traverse Speed ◽  
Abrasive Waterjet ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Cutting Head

The effects of the main operational machining parameters on the material removal rate (MRR) in abrasive waterjet turning (AWJT) are presented in this paper using a statistical approach. The five most common machining parameters such as water pressure, abrasive mass flow rate, cutting head traverse speed, workpiece rotational speed, and depth of cut have been put into a five-level central composite rotatable experimental design (CCRD). The main effects of parameters and the interaction among them were analyzed by means of the analysis of variance (ANOVA) and the response surfaces for MRR were obtained fitting a second-order polynomial function. It has been found that depth of cut and cutting head traverse speed are the most influential parameters, whereas the rotational speed is insignificant. In addition, the investigations show that interactions between traverse speed and pressure, abrasive mass flow rate and depth of cut, and pressure and depth of cut are significant on MRR. This result advances the AWJT state of the art. A complete model discussion has been reported drawing interesting considerations on the AWJT process characterising phenomena, where parameters interactions play a fundamental role.

scholarly journals Some characteristics of surfaces machined with abrasive waterjet turning

2021 ◽  
Keyword(s):  
Traverse Speed ◽  
Point Of View ◽  
Abrasive Waterjet ◽  
Depth Of Penetration ◽  
Machined Surface ◽  
Advantages And Disadvantages ◽  
Cutting Head ◽  
Constant Diameter ◽  
Machined Surface Quality ◽  
Turned Parts

Abstract This paper presents an experimental study of abrasive waterjet turning of an extrusion aluminum alloy (AlMg0,7Si). The aim of the paper is to determine differences of two methods from the point of view of machined surface quality and the depth of penetration, i.e., the diameter of the parts after the turning process. During the experiments, the traverse speed of the cutting head and the rotation of the turned parts were changed, other parameters, like pressure of the water, abrasive mass flow rate were kept constant. Diameter and some surface roughness parameters of the test parts were measured after the machining. On the base of experimental results, advantages, and disadvantages of two methods are explained in the paper.

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