Kerf Angle Research Articles

Preparation, characterisation and machining of LaPO<SUB align="right">4-Y<SUB align="right">2O<SUB align="right">3 composite by abrasive water jet machine

This article illustrates the work done on preparing a new ceramic matrix composite with the proportional concentration of Lanthanum phosphate (LaPO4) (80 wt.%) and Yttria (Y2O3) (20 wt.%) by aqueous sol-gel process. The prepared nano powder is compacted to 480 MPa at 28°C (room temperature) followed by sintering at 1,400°C for two hours to get the required disc shape geometry. The prepared ceramic matrix composite was machined using abrasive water jet machining (AWJM). Grey relational analysis (GRA) is performed with various input parameters like jet pressure (JP), stand-off distance (SOD) and traverse speed (TS) to measure the deviations in performance characteristics such as material removal rate (MRR), kerf angle (KA) and surface roughness (Ra). The significant correlations of these parameters were analysed by using analysis of variance (ANOVA). From the experimental work it is evident that SOD has significant contribution of about 60.89% and it affects the output performance characteristics to a great extent. Confirmation experiment is also carried out to validate the results.

Effect of abrasive waterjet machining on LaPO4/Y2O3 ceramic matrix composite

LaPO4/Y2O3 composite is identified as potential materials that possess low thermal conductivity and superior hardness and finds its application as high thermal barrier material and also a functional material. The objective of the study is to exhibit the correlation of three independent parameters of AWJM on LaPO4/Y2O3 composite prepared by Aqueous Sol-Gel process by response surface method (RSM). Jet pressure (JP), stand-off distance (SOD) and traverse speed (TS) are taken as the three independent parameters of AWJM. Effects of these parameters are measured and validated through three dependent responses of material removal rate (MRR), Kerf angle (KA) and surface roughness (Ra). To perform the experimental observations, central composite design (CCD) of L20 orthogonal array is used. Garnet of 80 meshes is used as abrasive. The microstructure of the cut region has plastic deformation surface with micro wear track and crack. Through RSM, it is identified that the three independent parameters have equal contributions on MRR and KA, where SOD has a significant effect on Ra.

Machinability performance of Al–NiTi and Al–NiTi–nano SiC composites with parametric optimization using GSA

The manuscript discusses the abrasive water jet machining (AWJM) of Al–NiTi and Al–NiTi–nano SiC composites to understand the influences and the effect of each parameter and to indentify optimal combination of AWJM parameters. The experiments are planned and conducted based on L27 orthogonal array. Pressure, standoff distance, and transverse feed rate are considered as input parameters; surface roughness and kerf angle are considered as output parameters. Gravitational search algorithm (GSA) is employed to identify the best possible combination of AWJM parameters. Regression model is used to develop the surface roughness and kerf angle model for Al–NiTi and Al–NiTi–nano SiC composites. The developed mathematical model is used as fitness function in GSA. It is found from the result of GSA that the optimal value for surface roughness of Al–NiTi composite is set at pressure 176 kPa, standoff distance 1 mm, and transverse feed 20 mm/min and for Al–NiTi–nano SiC composite is set at pressure 180 kPa, standoff distance 1.1 mm, and transverse feed 20 mm/min. Similarly, for kerf angle, the optimal value for Al–NiTi composite is set at pressure 260, standoff distance 1 mm, and transverse feed 20 mm/min and for Al–NiTi–nano SiC composite is set at pressure 255 kPa, standoff distance 1 mm, and transverse feed 20 mm/min. Analysis of variance is also performed to understand the effect of each input parameter on output response.

Utilization of solid-cutting waste of granite as an alternative abrasive in abrasive waterjet cutting of marble

Solid-cutting waste of granite is generated with considerable amounts during the machining processes. Utilization of this waste as an alternative material in various sectors such as construction and building would protect the environment and create a valuable source for the sectors. In this paper, an experimental study is carried out for the utilization of solid-cutting waste of granite as an abrasive material in abrasive waterjet (AWJ) cutting of marble. The solid-cutting waste of granite is downscaled with crushing and grinding. The obtained particles are then sieved in a range of size 150–300 μm. Some properties of the waste granite such as hardness and density are determined. Additionally, the cutting performance of the granite particles is compared to that of garnet based on some performance outputs including the cutting width, cutting depth, cutting-wear zone depth, kerf angle and surface roughness. During the cutting experiments, the cutting parameters are kept constant. Results show that the granite particles meet the requirements as an abrasive in the AWJ cutting of marble. It is revealed that the granite particles show similar performance with garnet in terms of the cutting width (granite: 2.10 mm and garnet: 2.21 mm) and the surface roughness (granite: 5.2 μm and garnet: 4.59 μm). It is determined that lower cutting depth (67% of the cutting depth produced by garnet, 15.62 mm) is obtained with the granite particles. Additionally, it is concluded that garnet produces lower kerf angles (70% and 79% of the kerf angle-access and kerf angle-exit produced by the granite particles, respectively). Finally, it can be noted that the granite particles can be effectively used in the cutting of marble and other rocks with similar density and hardness.

Mechanical and Machinability characteristics of Al–NiTi composites reinforced with SiC particulates

This paper discusses the effect of the addition of SiC in Al–NiTi composites on hardness and compression of the composites. The addition of SiC in the Al–NiTi composites significantly increases the hardness and compression strength. In addition to the mechanical properties, it also discusses the effect of abrasive water jet pressure, standoff distance, and feed rate during machining of the Al–NiTi–SiC composites. The surface roughness and kerf angle are considered as the output quality characteristics. Experiments are conducted based on L9 orthogonal array. The Techniques for Order of Preference by Similarity to Ideal Solution (TOPSIS) with entropy method is used to accomplish the objective of the experimental study. Entropy is a method used to compute the weight factor for each of the output performance characteristics. TOPSIS with entropy reveals that the optimal combination of the machining parameters for the multi-performance characteristics of Al–NiTi–SiC reinforced hybrid is set at a pressure of 225 MPa, standoff distance of 2, feed rate 40 mm/s, and weight percent of reinforcement 3%. The optimal results were compared with the experimental results for verifying the approach, and it is observed that the surface roughness decreases from 4.03 to 3.46 μm, and kerf angle decreases from 16.32 to 14.71.

Mathematical modelling on multiple variables in machining LaPO<SUB align="right">4/Y<SUB align="right">2O<SUB align="right">3 composite by abrasive waterjet

Abrasive water jet machine (AWJM) cutting technology is used to process many engineering materials which have low toughness and poor thermal conductive property. In this study, LaPO4/Y2O3 ceramic composite, that possesses no phase transformation at high operating temperature and good thermal barrier material, is used. AWJM with garnet of 80 mesh size as abrasive is characterised with various process parameters. Here, material removal rate (MRR), kerf angle (KA) and surface finish (Ra) are investigated by using the three influencing parameters such as jet pressure (JP), stand-off distance (SOD) and traverse speed (TS). L27 orthogonal array is used to record the experimental observations. The empirical model is developed by multilinear regression analysis (MRA) for MRR, KA and Ra. Analysis of variance (ANOVA) and response tables show the influences and the contribution of each independent variable over the dependent response.

Performance Evaluation of Abrasive Water Jet Machining on Banana Fiber Reinforced Polyester Composite

ABSTRACTThis work deals with the investigation of Abrasive Water Jet Machining (AWJM) on banana fiber reinforced polyester composite. The composite is prepared with 20 wt. % of fiber through hand layup method followed by compression molding. Experiments are conducted to assess the influence of each input parameters on the output responses namely surface roughness (Ra) and kerf angle. The study is performed by varying the water pressure, traverse speed (TS), and standoff distance (SD). From the experiments, it is observed that the standoff distance contributes more on affecting Ra by 60.63% and kerf angle by 74.80%. The suitable cutting parameters are suggested for achieving quality output and the cut surface morphology is observed through Scanning Electron Microscopic (SEM) images.

Optimization of Process Parameters for Machining Marble using Abrasive Water Jet Machining through Multi Response Techniques

Objective: Abrasive water jet machining is a most popular non-Traditional machining technique used for machining a wide range of hard-to-cut materials and complex geometric shapes. This technique is very much preferred for machining thermally sensitive materials. In the present study, Optimization of machining parameters such as water pressure, standoff distance (SOD) and quality of cut by were carried out by considering multiple performance characteristics such as high MRR, good surface finish (Ra) and minimum kerf Angle (Ka). Methods: The experiments were designed using Taguchi’s Design of experiments and carried out on Marble for each combination of (L9) orthogonal array. The optimal combinations of machining parameters were obtained using Taguchi Weightage method and principal component analysis. Findings: The analysis of the Taguchi method reveals that, MRR is significantly affected by stand-off distance while, surface roughness is affected by Abrasive flow rate. Improvements: Experimental results have shown that the output parameters have been improved using this approach.

A study on kerf characteristics of hybrid aluminium 7075 metal matrix composites machined using abrasive water jet machining technology

Metal matrix composites are difficult to machine in traditional machining methods. Abrasive water jet machining is a state-of-the art technology which enables machining of practically all engineering materials. This article deals with the investigation on optimization of process parameters of abrasive water jet machining of hybrid aluminium 7075 metal matrix composites with 5%, 10% and 15% of TiC and B4C (equal amount of each) reinforcement. The kerf characteristics such as kerf top width, kerf angle and surface roughness were studied against the abrasive water jet machining process parameters, namely, water jet pressure, jet traverse speed and standoff distance. Contribution of these parameters on responses was determined by analysis of variance. Regression models were obtained for kerf characteristics. Contribution of traverse speed was found to be more than other parameters in affecting top kerf width. Water jet pressure influenced more in affecting kerf angle and surface finish. The microstructures of machined surfaces were also analysed by scanning electron microscopy. The scanning electron microscopy investigations exposed the plastic deformation cutting of hybrid 7075 aluminium metal matrix composite. X-ray diffraction analysis results proved the non-entrapment of abrasive particle on the machined surface.

Effect of Abrasive Grain Size of the AWJM Performance on AA(6351)-SiC-B<sub>4</sub>C Hybrid Composite

In this work, Abrasive Water Jet Machining (AWJM) on aluminum based hybrid composite with Silicon Carbide (SiC) and Boron Carbide (B4C) reinforcement particles are investigated. Two different abrasive grain sizes of 80 mesh and 120 mesh are selected to carry out the experiments. The cutting parameters namely pressure, standoff distance (SOD) and traverse speed are assessed in terms of the kerf angle, Material Removal Rate (MRR) and Surface Roughness (Ra). The result shows that the coarse abrasive particle has a favorable effect on the MRR, while the fine grained abrasive particle produced minimum kerf angle and good surface finish.

Parametric Optimization of AWJM in AA6351-SiC-B<sub>4</sub>C Hybrid Composite Using Grey Relational Analysis

In the present study, the aluminum based hybrid composite with Silicon Carbide (SiC) and Boron Carbide (B4C) particles are prepared through the stir casting process and subjected to Abrasive Water Jet Machining (AWJM). The pressure, standoff distance and traverse speed are considered as the input process parameters and the output response such as Kerf angle, Material Removal Rate (MRR) and Surface Roughness (Ra) are measured and optimized using Grey Relational Analysis (GRA). The Analysis of Variance (ANOVA) and the F-test are performed to understand the contribution and the significant level of importance of each input parameter over the output response. The experimental result shows that the traverse speed and the standoff distance contributed more on affecting the performance, with a contribution of 62.14% and 18.43% respectively.

Investigation of multiple process parameters in abrasive water jet machining of tiles

This paper discusses the optimization of an abrasive water jet machining process with multiple characteristics, using the Taguchi orthogonal array and grey relational analysis (GRA). The machining process variables, such as mesh size, nozzle diameter, abrasive flow rate, water pressure, stand-off distance, and feed rate, were optimized with respect to multiple performance characteristics, namely, the surface roughness and the kerf angle. Experiments were performed using an L18 orthogonal array, and the optimum machining process variables were determined, using GRA. Analysis of variance was used to identify the most significant factor in the machining performance. A confirmatory test was performed to verify the improvement of the performance characteristics. The microstructure of the machined surfaces was also examined by scanning electron microscopy and atomic force microscopy. The results showed that the surface roughness and kerf angle were minimized under optimal machining conditions.

Multiresponse Analysis in Abrasive Waterjet Machining Process on AA 6351

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

Artificial neural network and regression models for performance prediction of abrasive waterjet in rock cutting

An experimental study is carried out for modeling the rock cutting performance of abrasive waterjet. Kerf angle (KA) is considered as a performance criteria and modeled using artificial neural network (ANN) and regression analysis based on operating variables. Three operating variables, including traverse speed, standoff distance, and abrasive mass flow rate, are studied for obtaining different results for the KA. Data belonging to the trials are used for construction of ANN and regression models. The developed models are then tested using a test data set which is not utilized during construction of models. Additionally, the regression model is validated using various statistical approaches. The results of regression analysis are also used to determine the significant operating variables affecting the KA. Furthermore, the performances of derived models are compared for showing the accuracy levels in prediction of the KA. As a result, it is concluded that both ANN and regression models can give adequate prediction for the KA with an acceptable accuracy level. The compared results reveal also that the corresponding ANN model is more reliable than the regression model. On the other hand, the standoff distance and traverse speed are statistically determined as dominant operating variables on the KA, respectively.

A study on the prediction of kerf angle in abrasive waterjet machining of rocks

In this study, the effects of the abrasive waterjet operating variables on the kerf angle were studied and the material properties were correlated with the kerf angle. The Taguchi method was followed to conduct the experimentation and the regression modeling was used in order to build models for prediction of dependent (kerf angle) from independent (operating and material properties) variables. Additionally, the adequacy of the model was tested using several statistical tests. The results indicated that not only operating variables themselves, but also the textural and mineralogical properties had discernible effects on the kerf angles. It was found from the correlation analysis that the water absorption, max grain size of rock-forming minerals and mean grain size of the rock had significant influences on the kerf angles of the rocks tested. Furthermore, it was determined that the kerf angles can be predicted by the developed models related to the rock types.

Performance of Abrasive Waterjet in Granite Cutting: Influence of the Textural Properties

In this study, influence of the textural properties, e.g., grain size and its boundaries, of granite on the cutting performance of abrasive waterjet (AWJ) was experimentally investigated. In the experiments, predimensioned granite samples were cut by an abrasive waterjet. Following the cutting process, the cut depth, surface roughness, and kerf angle of the granites were evaluated. As a result, it was disclosed that the cut depths and surface roughness increased when the grain size of the granites decreased. Contrary to the behavior of the cut depths and surface roughness of the granites, the kerf angle of the granites increased with an increase of the grain size. Conversely, it was concluded that the high number of the grain boundaries led to an obtainment of higher cut depths and surface roughness, whereas it caused a lower kerf angle. Additionally, it was found that the grains horizontally lying through the cutting line resulted in lower surface roughness and cut depths, whereas the grains vertically allocated through the cutting line resulted in higher cut depths and surface roughness.

Experimental Study on the Influence of Nozzle Diameter on Abrasive Jet Cutting Performance

Waterjet abrasive nozzle is the key component for accelerating abrasive particle velocity and its diameter has important influence on water jet. The relationship between nozzle diameter and waterjet cutting performance has been studied by experiment. The results show: The incision depth and width of specimen decrease linearly with the decreasing of nozzle diameter; The linearity of jet moving direction and the size of kerf angle of specimen are independent of nozzle diameter. Under the same pressure, reducing the nozzle diameter make the penetration capability to reduce, thus, the cutting quality decrease.