Cutting Force Dynamics as a Tool for Surface Profile Monitoring in AWJ

1995 ◽  
Vol 117 (3) ◽  
pp. 340-350 ◽  
Author(s):  
R. Kovacevic ◽  
R. Mohan ◽  
Y. M. Zhang

Abrasive waterjet cut surface is characterized using static and dynamic characterization techniques. A novel method of auto regressive moving average model identification called model distance method is utilized here for surface profile and dynamic force characterization. More information about the surface profile generating mechanism is derived through wavelength decomposition of the ARMA models. The dynamic workpiece normal force in abrasive waterjet is influenced by process parameters such as fluctuations in water pressure, change in abrasive flow rate, vibration of the positioning system, traverse speed, nozzle diameter, etc. An attempt has been made in this paper to link the dynamics of the process to the quality of the generated surface. The feasibility of using the dynamic workpiece normal force as a parameter for on-line monitoring of the surface profile generated by abrasive waterjet is also investigated.

Author(s):  
Barath M ◽  
◽  
Rajesh S ◽  
Duraimurugan P ◽  
◽  
...  

The abrasive mixed waterjet was with success utilized to chop several materials together with steel, metal and glass for a spread of business applications. This work focuses on surface roughness of hybrid metal matrix composite (AA6061, Al2O3, B4C). Machining was applied by AWJM (Abrasive Waterjet Cutting) at completely different parameters Water pressure, Traverse speed, Abrasive flow and stand-off distance. The reinforced composite was analyzed exploitation FE SEM (Field Emission Scanning lepton Microscope) and distribution of reinforced was studied by AFM (Atomic Force Microscopy). For optimum results surface roughness was calculated.


2019 ◽  
Vol 27 (03) ◽  
pp. 1950112 ◽  
Author(s):  
A. SHANMUGAM ◽  
K. KRISHNAMURTHY ◽  
T. MOHANRAJ

Surface roughness and taper angle of an abrasive waterjet machined surface of 7075 Aluminum metal matrix composite were deliberately studied. Response surface methodology design of experiments and analysis of variance were used to design the experiments and to identify the effect of process parameters on surface roughness and taper angle. The jet traverse speed and jet pressure were the most significant process parameters which influence the surface roughness and taper angle, respectively. Increasing the pressure and jet traverse speed results in increasing the surface roughness and taper angle. At the same time, decreasing the standoff distance and jet traverse speed possibly enhances both the responses. The optimal process parameters of 1[Formula: see text]mm as standoff distance, 192[Formula: see text]MPa as water pressure and 30[Formula: see text]mm[Formula: see text]min[Formula: see text] as jet traverse speed were identified to obtain the minimum value of surface roughness and taper angle. Based on the optimal parameters, the confirmation test was conducted. The mathematical equation was obtained from the experimental data using regression analysis; it was observed that the error was less than 5% of the experimentally measured values.


Author(s):  
Naresh Babu Munuswamy ◽  
M. Nambi Krishnan

This study investigates optimal parameter setting in abrasive waterjet machining (AWJM) on aluminium alloy AA 6351, using taguchi based Grey Relational Analysis (GRA) is been reported. The water pressure, traverse speed and stand-off-distance were chosen as the process parameters in this study. An L9 orthogonal matrix array is used for the experimental plan. The performance characteristics which include surface roughness (Ra) and kerf angle (KA) are considered. The results indicate that surface roughness and kerf angle decreases, with increase in water pressure and decrease in traverse speed. Analysis of variance (ANOVA) illustrates that traverse speed is the major parameter (89.7%) for reducing surface roughness and kerf angle, followed by water pressure (5.85%) and standoff distance (2%) respectively. The confirmation results reveal that surface roughness reduced by 16% and kerf angle reduced by 47%. Furthermore, the surfaces were examined under scanning electron microscope (SEM) and atomic force microscope (AFM) for a detailed study


Author(s):  
R Kovacevic ◽  
R Mohan ◽  
Y M Zhang

The surfaces produced by two different jet cutting processes, namely abrasive waterjet (AWJ) cutting and laser machining, are characterized for a comparative study. The surface profile measurements from experiments are modelled using auto regressive moving average (ARMA) models. The characteristics of the different profiles are identified by analysing these models. To describe the surface adequately, a sufficiently large sized sample is utilized for modelling. A novel method for identifying ARM A models based on the concept of model distance, which is ideal for large size samples, is adopted here. The relative advantages of this method are quantified in terms of the accuracy ratio. The profile characteristics (both dynamic as well as static) reveal more information about the nature of these processes. Scanning electron microscope (SEM) photographs of the surfaces generated by laser and AW J are analysed to obtain more insight into the physics of these processes.


2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Puneet Kumar ◽  
Bhavik Tank ◽  
Ravi Kant

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.


2014 ◽  
Vol 599-601 ◽  
pp. 555-559
Author(s):  
Iman Zohourkari ◽  
Mehdi Zohoor ◽  
Massimiliano Annoni

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.


2007 ◽  
Vol 24-25 ◽  
pp. 195-199 ◽  
Author(s):  
Quan Lai Li ◽  
Chuan Zhen Huang ◽  
Jun Wang ◽  
Hong Tao Zhu ◽  
Cui Lian Che

The potential of abrasive waterjet technology was investigated as a method to polish Z-blocks of synthetic quartz crystals. The polished surfaces were characterized by surface roughometer and scanning electron microscopy. The main factors affecting the surface roughness and the erosion mechanisms related to material removal were analysed. It is found that abrasive mesh, water pressure and jet incidence angle are the main factors affecting the surface roughness. By contrast, the influence of traverse speed on the surface roughness is small. Under certain controlled conditions, the erosion mechanisms of synthetic quartz crystals are plastic flow, leaving a crack-free surface by low-middle pressure micro abrasive waterjet.


2014 ◽  
Vol 621 ◽  
pp. 202-207
Author(s):  
Iman Zohourkari ◽  
Mehdi Zohoor ◽  
Massimiliano Annoni

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.


Author(s):  
Rishi Pahuja ◽  
M. Ramulu ◽  
M. Hashish

Fiber Metal Laminates (FML) are one of the most advanced engineered materials used in aerospace industry. The combination of metallic sheets interspersed in composite laminates in one hybrid material system provides higher impact and corrosion resistance when compared with their monolithic counterparts. However, due to the difference in machining responses for different material phases, conventional machining often induce damages and defects, affecting the cost and structural performance of the part. This research study investigates the machinability of thermoplastic Titanium Graphite (TiGr) FML. The feasibility and machinability of contouring thick (7.6 mm–10.5 mm) TiGr through Abrasive Waterjet (AWJ) process was studied in terms of machined kerf characteristics — taper ratio and surface quality. The effect of a wide range of process parameters was investigated such as geometric variables (mixing tube aspect ratio and orifice bore size), kinetic variables (water pressure, jet traverse speed) and abrasive load ratio on the machining quality. Predictive mathematical regression models were developed through Analysis of Variance (ANOVA) in order to optimize the process. Alongside, machined surface was examined to inspect the topological characteristics, material removal mechanism, and machining induced damage (micro-defects) and distortion through Surface Profilometry, Scanning electron and optical microscopy. A comparison was drawn between conventional and AWJ trimming of TiGr to demonstrate the superiority and high speed machining of AWJ with less damage.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5471
Author(s):  
Kumari Bimla Mardi ◽  
Amit Rai Dixit ◽  
Alokesh Pramanik ◽  
Pavol Hvizdos ◽  
Ashis Mallick ◽  
...  

This study investigated the effect of abrasive water jet kinematic parameters, such as jet traverse speed and water pressure, on the surface of magnesium-based metal matrix nanocomposites (Mg-MMNCs) reinforced with 50 nm (average particle size) Al2O3 particles at concentrations of 0.66 and 1.11 wt.%. The extent of grooving caused by abrasive particles and irregularities in the abrasive waterjet machined surface with respect to traverse speed (20, 40, 250 and 500 mm/min), abrasive flow rate (200 and 300 g/min) and water pressure (100 and 400 MPa) was investigated using surface topography measurements. The results helped to identify the mode of material disintegration during the process. The nanoindentation results show that material softening was decreased in nanocomposites with higher reinforcement content due to the presence of a sufficient amount of nanoparticles (1.11 wt.%), which protected the surface from damage. The values of selected surface roughness profile parameters—average roughness (Ra), maximum height of peak (Rp) and maximum depth of valleys (Rv)—reveal a comparatively smooth surface finish in composites reinforced with 1.11 wt.% at a traverse speed of 500 mm/min. Moreover, abrasive waterjet machining at high water pressure (400 MPa) produced better surface quality due to sufficient material removal and effective cleaning of debris from the machining zone as compared to a low water pressure (100 MPa), low traverse speed (5 mm/min) and low abrasive mass flow rate (200 g/min).


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