Boundary condition for deformation wear mode material removal in abrasive waterjet milling: Theoretical and experimental analyses

2017 ◽  
Vol 233 (1) ◽  
pp. 55-68 ◽  
Author(s):  
R Srikanth ◽  
N Ramesh Babu
Keyword(s):  
Boundary Condition ◽  
Material Removal ◽  
Impact Angle ◽  
Solid Particles ◽  
Abrasive Waterjet ◽  
Abrasive Particles ◽  
Modeling Methodology ◽  
Wear Mode ◽  
Abrasive Waterjets ◽  
Average Size

Producing quality features with abrasive waterjet milling requires the generation of shallow kerfs with low surface waviness. Typically, such kerfs are produced by deformation wear mode of material removal realized with certain combination of process parameters chosen based on an elaborate experimental analysis. Instead, these parameters can be selected through a modeling methodology developed based on deformation wear erosion theory. As a first part of this development, it is essential to identify the conditions for the prevalence of deformation wear during the generation of shallow kerfs with abrasive waterjets. To establish this condition, this article presents a theoretical analysis of kerf formation formulated based on deformation wear erosion by solid particles. In this analysis, the interaction of the abrasive particles with the material and the subsequent material removal through deformation wear is considered to define the geometry of the cutting front. The geometry of the cutting front was then used to determine the condition at which local impact angle of abrasives striking the cutting front changes to alter the mode of material removal from deformation wear to cutting wear. This analysis has brought out the boundary condition for deformation wear as the maximum depth of kerf to be equal to the average size of the abrasive particles used in the jet. The generic nature of this condition is established with kerfing experiments over three different ductile materials.

Turning With Abrasive-Waterjets—A First Investigation

1987 ◽  
Vol 109 (4) ◽  
pp. 281-290 ◽  
Author(s):  
M. Hashish
Keyword(s):  
Boron Carbide ◽  
Metal Matrix Composite ◽  
High Velocity ◽  
Metal Matrix ◽  
Material Removal ◽  
Cutting Tools ◽  
Abrasive Waterjet ◽  
Abrasive Particles ◽  
Near Net Shape ◽  
Abrasive Waterjets

Quantitative and qualitative results of a novel turning technique that employs abrasive-waterjets as cutting tools are presented. These jets are formed by mixing abrasive particles with a high-velocity (up to 600 m/s) waterjet in a specially designed mixing nozzle. Samples of magnesium boron carbide metal matrix composite, aluminum and glass were turned with the abrasive-waterjet tool. The effects of different parameters on the turning results are discussed. In general, the results illustrate the great potential of this technique to produce near-net-shape parts at fast material removal rates. Efforts for further research and optimization are discussed.

The Effect of Beam Angle in Abrasive-Waterjet Machining

1993 ◽  
Vol 115 (1) ◽  
pp. 51-56 ◽  
Author(s):  
M. Hashish
Keyword(s):  
Removal Rate ◽  
Rake Angle ◽  
Impact Angle ◽  
Abrasive Waterjet ◽  
Depth Of Cut ◽  
Abrasive Waterjet Machining ◽  
Coated Materials ◽  
Waterjet Machining ◽  
Abrasive Waterjets ◽  
The Impact

In the machining of materials, abrasive-waterjets are typically applied at a 90 deg. angle to the surface of the workpiece. This paper presents results and observations on machining with abrasive-waterjets at angles other than 90 deg. Previous visualization studies of the cutting process in transparent materials have shown that there are optimal angles for maximum depth of cut and kerf depth uniformity. Here, observations on the effect of angle in machining applications such as turning, milling, linear cutting, and drilling are addressed. The effects of variations in both the impact angle and the rake angle are investigated. Results indicate that the volume removal rate is significantly affected by these angles and that the surface finish can be improved by angling the jet. However, shallow angle drilling of small holes in laminated or ceramic-coated materials requires further investigation.

The Effects of Constant Kinetic Energy of Different Impacting Particles on Slurry Erosion Wear of AA 6063

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Bhushan D. Nandre ◽  
Girish R. Desale
Keyword(s):  
Silicon Carbide ◽  
Kinetic Energy ◽  
Mass Loss ◽  
Material Removal ◽  
Impact Angle ◽  
Solid Particles ◽  
Erosion Wear ◽  
Normal Impact ◽  
Sem Images ◽  
The Impact

The present experimental study investigates the effect of constant kinetic energy on erosion wear of aluminum alloy 6063. Three different natural erodents (quartz, silicon carbide, and alumina) with different particle sizes are used to impact at 45 deg and 90 deg impact angles. For calculating the number of particles in the slurry pot, it is assumed that the solid particles are of spherical shape. The total numbers of impacting solid particles were kept constant by adjusting the solid concentration, velocity, and test duration. The scanning electron microscope (SEM) images of the three erodents show that the alumina particles have sharp edges with more angularity, and silicon carbide particles have subangular nature while quartz particles are blocky in shape. The mass loss per particle at 45 deg impact angle is observed higher than at normal impact angle. It may be due to the change in material removal mechanism with changing the impact angle. It is also found that the mass loss per particle from the target material having different particle size with constant kinetic energy remains constant for respective erodents. This indicates that the velocity exponent of impacting particles is around 2. The SEM images of eroded surfaces reveal the different mechanisms of material removal at 45 deg impact angle and at normal impact angle.

Impact Erosion of Quartz Crystals by Micro-Particles in Abrasive Waterjet Micro-Machining

2013 ◽  
Vol 797 ◽  
pp. 46-51 ◽  
Author(s):  
H. Qi ◽  
J.M. Fan ◽  
Jun Wang
Keyword(s):  
Material Removal ◽  
Impact Angle ◽  
Machining Process ◽  
Abrasive Waterjet ◽  
Small Scale ◽  
Material Strength ◽  
Micro Machining ◽  
Micro Particles ◽  
Crater Volume ◽  
The Impact

Abrasive waterjet (AWJ) micro-machining is a precision processing technology with some distinct advantages. To understand the machining process, the erosion mechanism is presented and discussed when micro-particle impacting on a quartz crystal specimen. It is found that three types of impressions are formed which are craters, micro-dents and scratches. Small-scale craters including crashed zones and radial cracks are associated with plastic flow and subsurface micro-cracks that decrease the material strength, but cause little material removal, while large-scale craters including conchoidal fractures caused by the propagation of lateral cracks dominate the volume change of the specimen. Micro-dents are produced by the impact of particles possessing small kinetic energies, and scratches are generated by particle sliding or rolling over the target surface and make a negligible contribution to material removal. The crater volume generated by the impact of individual particle is then discussed with respect to particle impacting velocity and impact angle. It shows that an increase in particle impact angle or particle velocity increases the crater volume due to the increased conchoidal fractures during the impact process.

scholarly journals Impacts of Traverse Speed and Material Thickness on Abrasive Waterjet Contour Cutting of Austenitic Stainless Steel AISI 304L

2021 ◽  
Vol 11 (11) ◽  
pp. 4925
Author(s):  
Jennifer Milaor Llanto ◽  
Majid Tolouei-Rad ◽  
Ana Vafadar ◽  
Muhammad Aamir
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Traverse Speed ◽  
Abrasive Waterjet ◽  
Taper Angle ◽  
Material Thickness ◽  
Abrasive Waterjet Machining ◽  
Kerf Taper ◽  
Waterjet Machining

Abrasive water jet machining is a proficient alternative for cutting difficult-to-machine materials with complex geometries, such as austenitic stainless steel 304L (AISI304L). However, due to differences in machining responses for varied material conditions, the abrasive waterjet machining experiences challenges including kerf geometric inaccuracy and low material removal rate. In this study, an abrasive waterjet machining is employed to perform contour cutting of different profiles to investigate the impacts of traverse speed and material thickness in achieving lower kerf taper angle and higher material removal rate. Based on experimental investigation, a trend of decreasing the level of traverse speed and material thickness that results in minimum kerf taper angle values of 0.825° for machining curvature profile and 0.916° for line profiles has been observed. In addition, higher traverse speed and material thickness achieved higher material removal rate in cutting different curvature radii and lengths in line profiles with obtained values of 769.50 mm3/min and 751.5 mm3/min, accordingly. The analysis of variance revealed that material thickness had a significant impact on kerf taper angle and material removal rate, contributing within the range of 69–91% and 62–69%, respectively. In contrast, traverse speed was the least factor measuring within the range of 5–18% for kerf taper angle and 27–36% for material removal rate.

Development of a New Plate Polishing Technique with an Instantaneous Tiny-Grinding Wheel Cluster Based on Magnetorheological Effect

2008 ◽  
Vol 53-54 ◽  
pp. 155-160 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Ai Jun Tang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Abrasive Particles ◽  
Magnetorheological Effect ◽  
Material Removal Model ◽  
Mr Effect ◽  
Removal Model

A new plate polishing technique with an instantaneous tiny-grinding wheel cluster based on the magnetorheological (MR) effect is presented in this paper, and some experiments were conducted to prove its effectiveness and applicability. Under certain experimental condition, the material removal rate was improved by a factor of 20.84% as compared with the conventional polishing methods with dissociative abrasive particles, while the surface roughness of the workpiece was not obviously increased. Furthermore, the composite of the MR fluid was optimized to obtain the best polishing performance. On the basis of the experimental results, the material removal model of the new plate polishing technique was presented.

Non-Contact Ultrasonic Abrasive Machining of Wire-Electrical Discharge Machined SUS304 Steel

2017 ◽  
Author(s):  
K. L. Tan ◽  
S. H. Yeo
Keyword(s):  
Material Removal ◽  
Cavitation Erosion ◽  
Removal Rate ◽  
Recast Layer ◽  
Ultrasonic Machining ◽  
Abrasive Machining ◽  
Efficient Removal ◽  
Abrasive Particles ◽  
The Poor ◽  
Lower Material

Non-contact ultrasonic abrasive machining (NUAM) is a variant of ultrasonic machining (USM). In NUAM, material is removed predominantly by cavitation erosion in abrasive slurry. Due to a significantly lower material removal rate than traditional USM, NUAM is investigated for its applicability on surface modification and finishing in this study. Experiments were conducted on SUS304 steel samples machined by wire electrical discharged machining (WEDM). Due to the thermal spark phenomenon during WEDM, a thermal recast layer, of thickness approximately 15 μm, is often left over on the specimen’s surface after the process. The undesired thermal recast layer contributes to the poor surface integrity of specimens. A NUAM system was configured using a 40 kHz ultrasonic system. Ultrasonic vibration amplitude of 70 μm at the horn tip was used to generate cavitation bubbles in the abrasive slurry. NUAM was found to be effective in removing the unstable thermal recast layers by means of cavitation erosion. As a result, the average surface roughness, Ra, of the specimens improved from approximately 2.5 μm to ∼1.7 μm after 20 minutes of processing time. Furthermore, the addition of abrasive particles was observed to aid in more efficient removal of thermal recast layers than a pure cavitation condition.

scholarly journals Abrasive jet micro-machining of metals

2021 ◽  
Author(s):  
Sayeed Ally
Keyword(s):  
Normal Incidence ◽  
Impact Angle ◽  
Oblique Impact ◽  
Micro Machining ◽  
Surface Evolution ◽  
Abrasive Particles ◽  
Micro Features ◽  
Semi Empirical ◽  
First Time ◽  
Good Agreement

Abrasive jet micro-machining is a process that utilizes small abrasive particles entrained in a gas stream to erode material, creating micro-features such as channels and holes. Erosion experiments were carried out on aluminum 6061-T6, Ti-6A1-4V alloy, and 316L stainless steel using 50 μm A1₂O₃ abrasive powder launched at an average speed of 106 m/s. The dependence of erosion rate on impact angle was measured and fitted to a semi-empirical model. The erosion data was used in an analytical model to predict the surface evolution of unmasked channels machined with the abrasive jet at normal and oblique incidence, and masked channels at normal incidence. The predictions of the model were in good agreement with the measured profiles for unmasked channels at normal and oblique impact, and masked channels in at normal incidence up to an aspect ratio (channel depth/width) of 1.25. For the first time, it has been demonstrated that the surface evolution of features machined in metals can be predicted.

Material Removal and Application by Chemical Impact Reaction in Nano-Abrasive Jet Polishing

2013 ◽  
Vol 631-632 ◽  
pp. 550-555
Author(s):  
Wen Qiang Peng ◽  
Sheng Yi Li ◽  
Chao Liang Guan ◽  
Xin Min Shen
Keyword(s):  
Material Removal ◽  
Abrasive Particle ◽  
Precision Machining ◽  
Optical Surface ◽  
Polishing Process ◽  
Abrasive Particles ◽  
Mechanical Process ◽  
Abrasive Jet Polishing ◽  
Ultra Precision ◽  
Machining Properties

Material removed by mechanical process inevitably causes surface or subsurface damage containing cracks, plastic scratch, residual stress or dislocations. In nano-abrasive jet polishing (NAJP) the material is removed by chemical impact reaction. The chemical impact reaction is validated by contrast experiment with traditional lap polishing process in which the material is mainly removed through mechanical process. Experiment results show the dependence of the abrasive particles on the choice of materials. Even if the abrasive particle and the workpiece are composed of similar components, the machining properties are remarkably different due to slight differences in their physical properties or crystallography etc. Plastic scratches on the sample which was polished by the traditional mechanical process are completely removed by NAJP process, and the surface root-square-mean roughness has decreased from 1.403nm to 0.611nm. The NAJP process will become a promising method for ultra precision machining method for ultrasmooth optical surface.

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