Introduction of Premixed Micro-Abrasive Water Jet Technology for Deburring

2014 ◽  
Vol 1027 ◽  
pp. 177-182
Author(s):  
Chun Lin Qiu ◽  
Cheng Yong Wang ◽  
Yue Xian Song
Keyword(s):  
Impact Force ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Jet Formation ◽  
High Productivity ◽  
Residual Damage ◽  
New Type ◽  
The Difference ◽  
High Flexibility ◽  
The Impact

Micro-abrasive water jet technology for deburring is a new type of removing burrs technics with advantages of high productivity, high flexibility, no cutter damage and less residual damage etc, which is applied more and more extensively. This paper introduces the difference of premixed micro-abrasive water jet and post-mixed micro-abrasive water jet on jet formation, the difference of system principles and applications. This paper also provides the formula that how to quantitatively calculate the impact force of water jet. The principles and factors which influence on deburring and some application examples are also described in this paper.

scholarly journals Effect of Abrasive Concentration on Impact Performance of Abrasive Water Jet Crushing Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Xiaohui Liu ◽  
Ping Tang ◽  
Qi Geng ◽  
Xuebin Wang
Keyword(s):  
Internal Energy ◽  
Impact Force ◽  
Abrasive Particle ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Sph Method ◽  
Impact Performance ◽  
Water Jets ◽  
The Impact ◽  
Peak Impact Force

It has been found that the impact performance of water jets can be changed by its properties, which include pressure, additive, and mode of jet. Thus, an abrasive water jet (AWJ) has been developed as a new method. However, there is little research on the effect of abrasive concentration on the impact performance of abrasive jets. Thus, the SPH method is used to establish an abrasive water jet crushing concrete model to study the effect of abrasive concentration on the impact force, concrete internal energy, abrasive particle distribution, crushing depth, and damage and crushing efficiencies under different concrete compressive strengths and abrasive densities. The results indicate that there is little effect of the abrasive concentration on the peak impact force under different compressive strengths and abrasive densities, while the mean impact force tends to increase linearly with the abrasive concentration. The internal energy of the concrete increases stepwise with the abrasive concentration under different compressive strengths and abrasive densities. The concentration of 10%∼20% is the rapid increasing stage. The crushing depth and damage efficiencies are all maximum at a concentration of 20% under different compressive strengths and abrasive densities. After the concrete was impacted by the water from the water jet, it is divided into rebounding particles and intrusive particles. The more the intrusive particles, the easier the concrete to be crushed and damaged.

Analysis of Stresses in CFRP Composite Plates Drilled with Conventional and Abrasive Water Jet Machining

2013 ◽  
Vol 763 ◽  
pp. 127-143 ◽  
Author(s):  
M. Saleem ◽  
Habiba Bougherara ◽  
L. Toubal ◽  
F. Cénac ◽  
Redouane Zitoune
Keyword(s):  
Fatigue Testing ◽  
Composite Plates ◽  
Water Jet ◽  
Image Correlation ◽  
Initial Surface ◽  
Abrasive Water Jet ◽  
Machining Processes ◽  
Static Tests ◽  
The Difference ◽  
Conventional Machining

The aim of this paper is to analyze the influence of two machining processes on the mechanical behaviour of composite plates under cyclic loading. For this purpose, an experimental study using several CFRP plates drilled with conventional machining and non-conventional machining (abrasive water jet) was carried out. Digital image correlation and static tests using an Instron 4206 tester were performed. In addition, infrared thermography (IR) and fatigue tests were also performed to assess temperature and damage evolutions and also the stiffness degradation. Fatigue results have shown that the damage accumulation in specimens drilled with conventional machining was higher than the abrasive water jet ones. Furthermore, the endurance limit for plates drilled conventionally was approximately 10% higher than those drilled with abrasive water jet. This difference was related to the initial surface integrity after machining induced by the difference in the mechanism of material's removal between the two processes. The difference in surface texture was responsible for the initiation of stress concentration sites as evident from IR camera’s stress analysis. This was confirmed by SEM tests conducted after a destructive sectioning of the specimens before fatigue testing.

scholarly journals Analysis and modeling of the effects of process parameters on specific cutting energy in abrasive water jet cutting

2018 ◽  
Vol 22 (Suppl. 5) ◽  
pp. 1459-1470 ◽  
Author(s):  
Predrag Jankovic ◽  
Milos Madic ◽  
Dusan Petkovic ◽  
Miroslav Radovanovic
Keyword(s):  
Mathematical Model ◽  
Process Parameters ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Specific Cutting Energy ◽  
Important Indicator ◽  
Cutting Energy ◽  
Water Jet Cutting ◽  
Abrasive Water Jet Cutting ◽  
The Impact

The problem of cutting difficult-to-machine materials used in the aerospace industry, aircraft industry, and automobile industry, led to the development and application one of today?s most attractive technology for contour cutting - abrasive water jet cutting. For the efficient use of abrasive water jet cutting, it is of great importance to analyze the impact of process parameters on performance indicators, such as cutting quality, productivity, and costs. But also, from the energy utilization point of view, it is very important to analyze the impact of these parameters on the specific cutting energy which represents the amount of energy spent on the removal of material in the unit time. Having this in mind, this study presents the experimental results of abrasive water jet cutting of aluminum alloy with the aim of creating a mathematical model for estimating specific cutting energy as an important indicator of the degree of utilization of the available energy in the cutting process. The mathematical model of the specific cutting energy is explicitly represented as a non-linear function of the process parameters, obtained by the artificial neural network.

An experimental and simulation study of the flow pattern characteristics of water jet impingements in boreholes

2021 ◽  
pp. 014459872110520
Author(s):  
Yabin Gao ◽  
Xin Xiang ◽  
Ziwen Li ◽  
Xiaoya Guo ◽  
Peizhuang Han
Keyword(s):  
High Speed ◽  
Impact Force ◽  
Jet Impingement ◽  
Flow Patterns ◽  
Water Jet ◽  
Solid Boundary ◽  
Force Model ◽  
Water Jets ◽  
Contact Surfaces ◽  
The Impact

Hydraulic slotting has become one of the most common technologies adopted to increase permeability in low permeability in coal field seams. There are many factors affecting the rock breaking effects of water jets, among which the impact force cannot be ignored. To study the influencing effects of contact surface shapes on jet flow patterns and impact force, this study carried out experiments involving water jet impingement planes and boreholes under different pressure conditions. The investigations included numerical simulations under solid boundary based on gas–liquid coupling models and indoor experiments under high-speed camera observations. The results indicated that when the water jets impinged on different contact surfaces, obvious reflection flow occurred, and the axial velocity had changed through three stages during the development process. Moreover, the shapes of the contact surfaces, along with the outlet pressure, were found to have impacts on the angles and velocities of the reflected flow. The relevant empirical formulas were summarized according to this study's simulation results. In addition, the flow patterns and shapes of the contact surfaces were observed to have influencing effects on the impact force. An impact force model was established in this study based on the empirical formula, and the model was verified using both the simulation and experimental results. It was confirmed that the proposed model could provide important references for the optimization of the technical parameters water jet systems, which could provide theoretical support for the further intelligent and efficient transformation of coal mine drilling water jet technology.

Out of sight, out of mind? Supplier spatial proximity in French public procurement

2014 ◽  
Vol 27 (6) ◽  
pp. 486-500 ◽  
Author(s):  
Olivier Mamavi ◽  
Haithem Nagati ◽  
Frederick T. Wehrle ◽  
Gilles Pache
Keyword(s):  
Public Procurement ◽  
Spatial Proximity ◽  
Management Competencies ◽  
Content Type ◽  
The Public ◽  
Feature Evaluation ◽  
Negative Effect ◽  
New Type ◽  
The Difference ◽  
The Impact

Purpose – The purpose of this paper is to study the impact of spatial proximity on supplier selection in the French public sector. While French public procurement legislation forbids consideration of supplier location in the procurement process, public contractors may still rely on spatial proximity for complex transactions necessitating mutual adjustments with suppliers. Design/methodology/approach – Using French Official Journals (BOAMP), the authors compiled 565,557 transactions completed on three public procurement markets between 6,182 contractors and 26,570 suppliers, over a period of six years (between 2006 and 2011). The authors conducted a two-level hierarchical linear auto-regression analysis and a feature evaluation analysis for all transactions. Findings – The paper finds significant variation between the transactions on different markets: a negative effect of spatial proximity on the number of contract notices in the public market and a positive effect of spatial proximity on the number of notices in the services and supplies markets. The difference lies in the levels of mutual adjustment required to optimally manage the relationship between public contractor and supplier. Research limitations/implications – The research is based on an econometric analysis conducted uniquely in the French context, which calls into question the external validity of the results obtained. The study also rests on segmentation into three aggregate markets, which might be considered too general. Originality/value – Rather than analyze public contractors’ perceptions of the importance of the criterion of spatial proximity, the paper examines 565,557 actual transactions. The results point to the emergence of a new type of relationship with certain suppliers, which should lead public contractors to integrate relationship management competencies, in addition to legal and economic competencies, in the organization of calls for tenders.

Vibration and Experimental Comparison of Machining Process

2015 ◽  
Vol 669 ◽  
pp. 179-186 ◽  
Author(s):  
Anton Panda ◽  
Marek Prislupčák ◽  
Jozef Jurko ◽  
Iveta Pandová ◽  
Peter Orendáč
Keyword(s):  
Water Jet ◽  
Machining Process ◽  
Experimental Comparison ◽  
Abrasive Water Jet ◽  
Technological Parameters ◽  
Microsoft Excel ◽  
Frequency Spectra ◽  
Acceleration Amplitude ◽  
The Impact ◽  
The Given

Abrasive water jet technology is among the unconventional ways of machining. In today's modern and progressive era is often used for cutting and machining of various types of materials because of lower costs and environmental impact, as the cutting tool is water, in our case, with the addition of abrasives. Objective of the measurements was to evaluate the impact of vibration on the technological head in abrasive water jet technology in changing the selected technological parameters and the flow rate of technological head. In the given experiment, the used material - steel Hardox 500 with a thickness of 10 mm. The effort was to investigate the effects of changes in the speed rate of technological head (by speeds - 40, 200, 400 mm / min) on the size of the vibration acceleration amplitude and its frequency. Based on the measured values ​​of vibration to the technological head create the database and from it is evaluated the data in selected softwares (LabVIEW, SignalExpress and Microsoft Excel). Findings and conclusions are formulated on the basis of graphical dependencies, envelopes frequency spectra and comparison chart of envelopes.

Diagnostic and Experimental Valuation on Progressive Machining Unit

2014 ◽  
Vol 616 ◽  
pp. 191-199 ◽  
Author(s):  
Marek Prislupčák ◽  
Anton Panda ◽  
Marek Jančík ◽  
Iveta Pandová ◽  
Peter Orendáč ◽  
...  
Keyword(s):  
Feed Rate ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Technological Parameters ◽  
Microsoft Excel ◽  
Frequency Spectra ◽  
New Findings ◽  
Acceleration Amplitude ◽  
Vibration Impact ◽  
The Impact

The main effort of each technological process is not only to reduce the costs, but also to reduce the impact on the environment. The technology of abrasive water jet is one of the methods of division and cutting materials with the lowest impact on the environment, since water is the cutting tool, in our case with the addition of an abrasive. The aim of the measurement was the observation (examination) and evaluation of the vibration impact on the technological head in the technology of abrasive water jet when changing the selected technological parameters, namely the feed rate of the technological head. The experiments were carried out on one kind of material - steel HARDOX 500 with a thickness of 10 mm. The impact of the change of the technological head’s feed rate (100, 50, mm/min) on the size of the vibration acceleration amplitude and its frequency were examined. A database was created from the measured vibration values on the technological head and from that database the data was evaluated in selected softwares (LabVIEW, SignalExpress a Microsoft Excel). Graphical dependencies, frequency spectra covers and covers comparison graph were created from which new findings and conclusions were formulated.

Measurement and Analysis of Mass Flow and Feed Speed Impact on Technological Head Vibrations during Cutting Abrasion Resistant Steels with Abrasive Water Jet Technology

2015 ◽  
Vol 669 ◽  
pp. 243-250 ◽  
Author(s):  
Štefánia Salokyová
Keyword(s):  
Mass Flow ◽  
Manufacturing Systems ◽  
Water Jet ◽  
Feed Speed ◽  
Abrasive Water Jet ◽  
Technological Parameters ◽  
Physics Institute ◽  
Technical University ◽  
Manufacturing Technologies ◽  
The Impact

The article presents the results of Technical University in Košice Faculty of Manufacturing Technologies Department of production processes operation and Technical University in Ostrava Physics Institute Liquid jet workplace cooperation in the area of operational states diagnosis of manufacturing systems with abrasive water jet technology (AWJ). Within the operational states diagnostics is the impact of selected technological parameters on technological head vibrations studied. Based on an extensive set of experiments are original graphical dependences determined of the abrasive mass flow and feed speed impact on the vibrations parameter - technological head vibrations acceleration amplitude of manufacturing system with AWJ technology. In addition to the original graphical dependences are in article new knowledge formulated in the area of science and research and recommendations for companies that operates manufacturing systems with AWJ technology.

Numerical Simulation and Experimental Investigation of the Gas-Liquid-Solid Three-Phase Flow Outside of the Abrasive Water Jet Nozzle

2010 ◽  
Vol 431-432 ◽  
pp. 90-93 ◽  
Author(s):  
Rong Guo Hou ◽  
Chuan Zhen Huang ◽  
Hong Tao Zhu ◽  
Qing Zhi Zhao
Keyword(s):  
Fluid Dynamic ◽  
Vibration Signal ◽  
Simulation Method ◽  
Water Jet ◽  
Phase Flow ◽  
Abrasive Water Jet ◽  
Three Phase ◽  
Three Phase Flow ◽  
Force Signal ◽  
The Impact

Simulation of the gas-liquid-solid three-phase flow field of outside the abrasive water jet(AWJ) nozzle is studied by the computed fluid dynamic software- FLUENT, and the velocity field of the three-phase flow is obtained, the velocity value of the flow between the nozzle and work-pieces is also obtained. Serial experiments have been done to verify the simulation method. In the experiments, the impact force signal of the AWJ outside the nozzle is collected by the piezoelectricity ergometer, then it is filtered by the vibration signal and dynamic signal software. The testing values are transformed to the velocity values, which will be compared with the simulation values. The comparison result indicates that the value of the simulation is changing similarly with the experiment value, and both value is almost the same, which proves that the simulation method is successful, the simulation model and the boundary conditions are right.

scholarly journals Influence of Local Temperature Changes on the Material Microstructure in Abrasive Water Jet Machining (AWJM)

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5399
Author(s):  
Sławomir Spadło ◽  
Damian Bańkowski ◽  
Piotr Młynarczyk ◽  
Irena M. Hlaváčová
Keyword(s):  
Local Heat Transfer ◽  
Water Jet ◽  
Local Temperature ◽  
Adjacent Area ◽  
Abrasive Water Jet ◽  
Material Microstructure ◽  
Temperature Changes ◽  
Abrasive Water Jet Machining ◽  
Jet Impact ◽  
The Impact

This article considers effects of local heat transfer taking place insteel cutting by abrasive water jet machining (AWJM). The influence of temperature changes during AWJM has not been investigated thoroughly. Most studies on AWJM suggest that thermal energy has little or no effect on the material cut. This study focused on the analysis of the material microstructure and indentation microhardness in the jet impact zone and the adjacent area. The structure features revealed through optical metallography and scanning microscopy suggest local temperature changes caused by the impact of the abrasive water jet against the workpiece surface. From the microscopic examinationand hardness tests, it is clear that, during the process, large amounts of energy were transferred locally. The mechanical stress produced by the water jet led to plastic deformation at and near the surface. This was accompanied by the generation and transfer of large amounts of heat resulting in a local rise in temperature to 450 °C or higher.

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