Combining with the electron microscope analysis of the morphology of incision, the mechanism of abrasive water jet cutting metal materials was carried out to explore, for the rational selection of ...abrasive jet cutting parameters, to extend its application to provide the basis. Study shows that the abrasive water jet cutting metal materials, the material damage mechanism is mainly to yield deformation and failure and shear of grinding damage, grooving formation is mainly caused by falling impact deformation and furrows grinding.
The process of the abrasive water jet cutting of materials, supported by the
theories of fluid mechanics, abrasive wear and damage mechanics, is a
high-tech technologies that provides unique ...capabilities compared to
conventional machining processes. This paper, along the theoretical
derivations, provides original contributions in the form of mathematical
models of the quantity of the cut surface damage, expressed by the values of
cut surface roughness. The particular part of this paper deal with the
results of the original experimental research. The research aim was connected
with the demands of industry, i.e. the end user. Having in mind that the
conventional machining processes are not only lagging behind in terms of
quality of cut, or even some requests are not able to meet, but with the
advent of composite materials were not able to machine them, because they
occurred unacceptable damage (mechanical damage or delamination, fiber
pull-out, burning, frayed edges).
Proces secenja materijala abrazivnim vodenim mlazom, podrzan teorijom
mehanike fluida, abrazivnog habanja i mehanikom ostecenja, je visoko
tehnoloski postupak koji nudi jedinstvene mogucnosti u poredjenju sa
konvencionalnim postupcima obrade. U radu se, pored teorijskih izvodjenja,
daje originalni doprinos u obliku matematickog modela velicine ostecenja
povrsine reza, izrazene vrednoscu hrapavosti. Cilj istrazivanja, prikazanih u
radu, povezan je sa zahtevima industrije, odnosno krajnjeg korisnika. Imajuci
u vidu da konvencionalni postupci obrade ne samo da su u zaostatku u sto se
tice kvaliteta reza, vec i da izvesne zahteve nisu mogli da ispune, sa
pojavom kompozitnih materijala nisu uopste bili u stanju da ih obradjuju, jer
su se javljala nedozvoljena ostecenja, kao sto su reslojavanje, izvlacenje
vlakana, sagorevanje krajeva).
Basisning on two-phase flow theory and using the FLUENT fluid analysis software to do numerical simulation in High pressure abrasive water jet. Changing the viscositythe flow and the density to ...observe the Influence in the field of force and velocity distribution. The results show that: density increases can improve the force and velocity significantly; but viscosity increase has a opposite effect, since the flow resistance increasing, making the outlet velocity fast decay. On the other hand, the flow of the working medium can also have a greater impact on the inlet velocity and jet results. An appropriate increase within the allowable range in the device can improve jet results.
This paper describes works of the post-mixed abrasive water jet, and makes kinetic energy analysis to the single abrasive particles from the theory angle, In addition, does some research such as Jet ...pressure, abrasive flow, the speed of nozzle movement and Incident angle on the influence of the removal rate.Through the control of technological parameters, the paper studies polishing removal mechanism of single abrasive particles for stainless steel on the grades of 0Cr18Ni9Si,Thus which provides theoretical basis and practical guidance for the cold polishing processing of profile surface.
This paper reports the effect of recycling of local garnet abrasives (origin: southern India) while cutting aluminium using abrasive water jet machining. The influence of pressure, traverse rate, and ...abrasive flow rate on American Foundrymen’s Society grain fineness number, average particle size, depth of cut, top kerf width, bottom kerf width, kerf taper, and surface finish obtained using a specially formulated optimised abrasive test sample have been studied. The performance of the test sample has been compared with that of commercial grade abrasive of mesh size 80. Recycling studies, undertaken with used abrasives after screening out particles less than 90
μm size and also with all particles without screening are reported. It is found that the test sample performed better than mesh size 80 abrasives, in terms of achievable depth of cut and surface finish. Recycled abrasives reduces kerf taper, improving the parallelism of cut surface. These results indicate that the proper selection of abrasive particle size distribution is necessary for achieving improved results. The reusability percentage of test sample of the local abrasives that can be recycled is determined as 81%.
Abrasive water jet cutting technology is widely applied in the materials processing today and attracts great attention from scholars, but many phenomena concerned are not well understood, especially ...in the internal jet flow of the cutting head at the condition of ultra-high pressure. The multiphase flow in the cutting head is numerically simulated to study the abrasive motion mechanism and wear inside the cutting head at the pressure beyond 300 MPa. Visible predictions of the particles trajectories and wear rate in the cutting head are presented. The influences of the abrasive physical properties, size of the jewel orifice and the operating pressure on the trajectories are discussed. Based on the simulation, a wear experiment is carried out under the corresponding pressures. The simulation and experimental results show that the flow in the mixing chamber is composed of the jet core zone and the disturbance zone, both affect the particles trajectories. The mixing efficiency drops with the increase of the abrasive granularity. The abrasive density determines the response of particles to the effects of different flow zones, the abrasive with medium density gives the best general performance. Increasing the operating pressure or using the jewel with a smaller orifice improves the coherency of particles trajectories but increases the wear rate of the jewel holder at the same time. Walls of the jewel holder, the entrance of the mixing chamber and the convergence part of the mixing tube are subject to wear out. The computational and experimental results give a qualitative consistency which proves that this numerical method can provide a reliable and visible cognition of the flow characteristics of ultra-high pressure abrasive water jet. The investigation is benefit for improving the machining properties of water jet cutting systems and the optimization design of the cutting head. (copyright sign)2009 Chinese Journal of Mechanical Engineers.
The abrasive water jet (AWJ) cutting method has been used widely for the cutting and processing of materials because of its cool, damage-free, and precise cutting technique. Nowadays, the use of AWJ ...cutting in the natural stone industry is increasing. However, the effectiveness of AWJ cutting of natural stones is dependent on the rock properties and machine operating parameters. In this study, injection-type AWJ cutting was applied to 42 different types of natural stones to investigate the effects of rock properties and operating parameters on the cutting depth. Shore hardness, Bohme surface abrasion resistance and the density of the rocks were the most significant rock properties affecting the cutting depth. The working pump pressure and traverse velocity were the most significant operating parameters affecting cutting, as has been shown previously. The relationships between the rock properties or operating parameters and the cutting depth were evaluated using multiple linear and nonlinear regression analyses, and estimation models were developed. Some of the models included only rock properties under fixed operating conditions, and others included both rock properties and operating parameters to predict cutting depth. The models allow for the preselection of particular operating parameters for the cutting of specific rocks types. The prediction of cutting depth is a valuable tool for the controlled surface machining of rock materials.
The abrasive water jet (AWJ) cutting method has been used widely for the cutting and processing of materials because of its cool, damage-free, and precise cutting technique. Nowadays, the use of AWJ ...cutting in the natural stone industry is increasing. However, the effectiveness of AWJ cutting of natural stones is dependent on the rock properties and machine operating parameters. In this study, injection-type AWJ cutting was applied to 42 different types of natural stones to investigate the effects of rock properties and operating parameters on the cutting depth. Shore hardness, Bohme surface abrasion resistance and the density of the rocks were the most significant rock properties affecting the cutting depth. The working pump pressure and traverse velocity were the most significant operating parameters affecting cutting, as has been shown previously. The relationships between the rock properties or operating parameters and the cutting depth were evaluated using multiple linear and nonlinear regression analyses, and estimation models were developed. Some of the models included only rock properties under fixed operating conditions, and others included both rock properties and operating parameters to predict cutting depth. The models allow for the preselection of particular operating parameters for the cutting of specific rocks types. The prediction of cutting depth is a valuable tool for the controlled surface machining of rock materials.
The abrasive water jet (AWJ) cutting method has been used widely for the cutting and processing of materials because of its cool, damage-free, and precise cutting technique. Nowadays, the use of AWJ ...cutting in the natural stone industry is increasing. However, the effectiveness of AWJ cutting of natural stones is dependent on the rock properties and machine operating parameters. In this study, injection-type AWJ cutting was applied to 42 different types of natural stones to investigate the effects of rock properties and operating parameters on the cutting depth. Shore hardness, Bohme surface abrasion resistance and the density of the rocks were the most significant rock properties affecting the cutting depth. The working pump pressure and traverse velocity were the most significant operating parameters affecting cutting, as has been shown previously. The relationships between the rock properties or operating parameters and the cutting depth were evaluated using multiple linear and nonlinear regression analyses, and estimation models were developed. Some of the models included only rock properties under fixed operating conditions, and others included both rock properties and operating parameters to predict cutting depth. The models allow for the preselection of particular operating parameters for the cutting of specific rocks types. The prediction of cutting depth is a valuable tool for the controlled surface machining of rock materials.
Nozzle wear dependence on abrasive water jet system parameters and nozzle geometry is experimentally investigated. Experimental procedures for evaluating long term and accelerated nozzle wear are ...discussed. Accelerated wear tests are conducted to study the effects of nozzle length, inlet angle, diameter, orifice diameter, abrasive flow rate, and water pressure on wear. An empirical model for nozzle weight loss rate is developed and is shown to correlate well with experimental measurements.