AN INVESTIGATION OF MACHINABILITY & SURFACE INTEGRITY ON ALUMINIUM AND TITANIUM CARBIDE COMPOSITE MATERIAL USING ABRASIVE WATER JET MACHINING

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 10, October 2017, pp , Article ID: IJMET_08_10_041 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed AN INVESTIGATION OF MACHINABILITY & SURFACE INTEGRITY ON ALUMINIUM AND TITANIUM CARBIDE COMPOSITE MATERIAL USING ABRASIVE WATER JET MACHINING S. A. Puviyarasu Department of Mechanical Engineering, Dr. N.G.P Institute of technology, Affiliated to Anna University, Coimbatore, Tamilnadu, India ABSTRACT The experimental investigation was conducted to determine the influence of machinability and surface integrity on aluminium and titanium carbide composite material using abrasive water jet machining (AWJM). The matrix is aluminium and the reinforcement is titanium carbide, varies from 0-8 %. The effects of AWJ machining parameters were Speed, standoff distance and Reinforcement was considered as model variables. For this purpose, design of experiments was carried out in order to collect the material removal rate and surface roughness. Then the Analyses of variance (ANOVA) were carried out to check the validity of regression model and to determine the significant parameter influencing the surface roughness and Material removal rate. The experimental result shows that these hybrid process parameters can fit the requirements of modern manufacturing applications. Keywords: Abrasive water jet machining (AWJM), ANOVA, Material Removal Rate (MRR), Surface Roughness(RA). Cite this Article: S. A. Puviyarasu, An Investigation of Machinability & Surface Integrity on Aluminium and Titanium Carbide Composite material using Abrasive water jet Machining, International Journal of Mechanical Engineering and Technology 8(10), 2017, pp INTRODUCTION In many developed countries and in several developing countries there exists continued interest in Metal Matrix Composites (MMCs). Researchers tried numerous combinations of matrices and reinforcements since 1950s. This led to developments for aerospace, but resultant commercial applications were limited. To enhance further the properties of MMCs more than two materials were added in the matrix to give birth to hybrid metal matrix composites. However, conventional monolithic materials have limitations in achieving good combination of strength, stiffness, toughness and density [1]. To overcome these

2 An Investigation of Machinability & Surface Integrity on Aluminium and Titanium Carbide Composite material using Abrasive water jet Machining shortcomings and to meet the ever increasing demand of modern day technology, composites are the most promising materials of recent interest. Metal matrix composites (MMCs) possess significantly improved properties including high specific strength; specific modulus, damping capacity and good wear resistance compared to the unreinforced alloys [2]. But the poor ductility and reduced fracture toughness limits the applications of conventional composite MMCs. To improve the fracture toughness of the conventional composites, the new class of materials known as Metal Matrix Composites (MMCs) are developed by reinforcing particles in the micro metal scale. SiC and Al 2 O 3 are the common reinforcing materials used in aluminium matrix composites. Limited research been conducted on Titanium carbide reinforced and aluminium matrix composites which have a combination of two or more reinforcements. Here we are using aluminium and titanium carbide as a composite material; it varies from 0-8%. Abrasive water jet machining (AWJM) is suitable to be used for hard and brittle materials with excellent machining performances; it is most frequently used in the surface finishing, cleaning, deburring for the materials such as steels, glass and ceramics [3]. The capability of the AWJM process used for specific materials with high efficiency, accuracy and low cost was conducted to meet the requirement of modern industrial applications. [4]. The three input process parameters namely standoff distance, speed and reinforcement percentage were chosen as variable to study their effects on response parameter. The ranges of input parameter were selected on the basis of literature survey, machine capability and preliminary experiments conducted by using one variable at a time approach. M. Hashish et al. [5] experimentally investigated the wear behaviour of abrasive-water jet nozzle materials. Two general patterns of wear namely the divergent and convergent were observed. Divergent pattern occurs when soft mixing tube materials or relatively hard abrasives were used, while convergent pattern occurs otherwise.. For this purpose, design of experiments was carried out in order to collect the material removal rate and surface roughness. Shah and Patel [6] reported that the MRR increases with increase of air pressure, grain size and with increase in nozzle diameter. Initially MRR increases and then it is almost constant for small range. After that MRR decreased as SOD increases. Khan, Haque [7] experimented the relationship between work feed rate and taper of cut during AWJM using different abrasive materials. For all types of abrasives the taper of cut shows an increasing trend with increase in work feed rate. With increase in work feed rate the machining zone is exposed to the jet for a shorter time. Then the Analyses of Variance (ANOVA) were carried out to determine the significant parameter influencing the surface roughness and material removal rate. The proposed experimental procedure and results leads to improvements in response parameters. It is fit to the requirement of modern manufacturing applications. 2. EXPERIMENTAL SETUP: 2.1 Materials: The work piece adopted in this study was Aluminium and titanium carbide composite material, with dimensions of 100mm* 100mm*10mm. Aluminium is the third most abundant element after oxygen and silicon and the most abundant metal in the crust, though it is less common in the mantle below and the Titanium carbide is the only chemical compound of titanium and carbon it has attracted for the sake of its excellent properties such as hard and wear- resistance, high melting point and chemically inert [8]. The specimens were milled and grained firstly to ensure their parallelism before each experiment. The essential properties of the material is given below editor@iaeme.com

3 S. A. Puviyarasu Property Table 1 Essential Properties of Aluminium alloy Value Melting Point Boiling Point 2480 Thermal Conductivity (0-100 C) 0.57 Density (g/cm³) Poissons Ratio Equipment and procedure Initially, the aluminium alloy and the reinforcement material are fabricated by using stir casting process. This involves Matrix material aluminium alloy as taken in rod form was melted at 800 o C in the electric resistance furnace. Preheating of reinforcement particles (titanium carbide ) was done for one hour for 790 o C to remove moisture content and gasses from the surface of the particulates. The speed of the stirrer was gradually raised upto 500rpm and the preheated reinforcement particles were added into the melt. The speed regulator maintained at a constant speed of the stirrer, after the addition of hard ceramic (reinforcement) particles stirring was continued for 5-7minutes for proper mixing of reinforcement in the matrix. After fabrication of the material, the experiments were conducted on the Abrasive Water Jet Machining (AWJM). Considerable research and development effort has been made in recent years to develop new techniques to enhance the cutting performance of this technology such as the depth of cut and surface finish. Some newly developed techniques include cutting with forward angling the jet in the cutting plane, multiple pass cutting and controlled nozzle oscillation. Among these new techniques, controlled nozzle or cutting head oscillation has been found to be one of the most effective ways in improving the cutting performance without additional costs to the process. The three input process parameters namely standoff distance, speed and reinforcement percentage were chosen as variable to study their effects on response parameter in Fig. 1. Figure 1 Abrasive Water jet machine The ranges of input parameter were selected on the basis of literature survey, machine capability and preliminary experiments conducted by using one variable at a time approach. As work piece material, the titanium carbide with aluminium composites with 100mm 100mm 10mm size was used. Moreover the material would be splashed and impinged by high speed of abrasive grains. The specimens were cut into 10mm to diameter from the editor@iaeme.com

4 An Investigation of Machinability & Surface Integrity on Aluminium and Titanium Carbide Composite material using Abrasive water jet Machining thickness of 10mm. Therefore, the surplus material was removed and surface finishing would be enhanced. 2.3 Conditions The essential machining parameters such as abrasive grain size, pressure, nozzle diameter, working medium as shown below Figure 2 Schematic diagram of operation of AWJM Process Table 2 Experimental Conditions Work condition Nozzle diameter Pressure Abrasive size Abrasive material Working time/piece Description 1.1mm 3600psi 80 mesh Silicon sand sec 3. RESULTS AND DISCUSSION The experiments were designed and conducted by employing response surface methodology (RSM). The selection of appropriate model and development of response surface models have been carried out by using statistical software, Mini tab (16). The selected models were obtained for the response characteristics, viz., surface roughness, material removal rate. The surface roughness and material removal rate is the most important parameters for assessing a production process. In this investigation, we have found that rougher surface of the material after machining due to the fact that as the particle moves down they loses its kinetic energy and their ability. By analysing the experimental data of the selected material, it found that optimum selection of the input parameters i.e. Speed, Standoff distance and Reinforcement (%) are crucial in controlling the material removal rate and surface roughness. The effect of each parameter was studied while keeping other parameters as constant. Then How the Input parameters influence the output is carried out by using analysis of variance (ANOVA) was performed. It analyse the statistical results. For analysis of data, checking the lack of fit of model is required. For this purpose Analysis of Variance (ANOVA) is performed editor@iaeme.com

5 S. A. Puviyarasu S.NO 3.1 PROCESS PARAMETERS AND THEIR LEVELS The process parameters and their levels is shown in Table 3 Table 3 Process parameter and their levels PROCESS PARAMETERS STAND OFF DISTANCE SPEED % REINFORCEMENT EXPERIMENTAL RESULTS According to central composite design with three control factors at half fraction, a total of 25 experiments need to be performed as shown in table 4. Each time experiment was performed, a particular set of control factors were chosen and work piece was cut. Table 4 Experimental results of material removal rate and surface roughness STAND OFF DISTANCE SPEED REINFORCEMENT TIME MRR RA editor@iaeme.com

6 An Investigation of Machinability & Surface Integrity on Aluminium and Titanium Carbide Composite material using Abrasive water jet Machining 3.3 ANALYSIS OF VARIANCE (ANOVA) Material Removal Rate The ANOVA is carried out to analyse the effect of process parameters table 5 shows the input parameters source and how they contribute or Influence the Material Removal rate. Table 6 shows the response level data. In Table 5 the standoff distance plays a more important role in contributing the material removal rate of and followed by reinforcement* reinforcement Thus the SOD has the maximum contribution of 98.75% and followed by R*R of 0.64% contribution. The total sum of square and mean of square significantly contribute same as shown in table 5 Table 5 Analysis of variance for MRR Source DOF SS MS SS Contribution% MS Contribution% SOD Speed Reinforcement SOD*SOD Speed*Speed R*R SOD*Reinforcement Speed*Reinforcement Total % 99.99% DF- Degrees of freedom, SS- Sum of squares, MS-Mean square (Variance) Table 6 Response Table for MRR Source SOD R*R SOD*SOD % 0.64% 0.22% Rank Figure 3 3D Surface plot MRR for SOD versus speed editor@iaeme.com

7 S. A. Puviyarasu Figure 4 3D Surface plot MRR for SOD versus Reinforcement % Figure 5 3D Surface plot MRR for Speed versus Reinforcement % From the Figure 3 it is observed that the speed is directly proportional to the MRR whereas the MRR decreases initially and then increases gradually with the increase in SOD by considering the speed. From Figure 4. It is observed that the MRR is directly proportional to Reinforcement % whereas the MRR increases initially and decreases gradually with increase in SOD by considering the Reinforcement %. Figure 5 shows that the MRR increases initially and decreases gradually with decrease in Reinforcement % and by considering increase in speed SURFACE ROUGHNESS The table.7 shows the input parameters source and how they contribute or Influence the Surface roughness. Table.8 shows the Response level data. In table.7 standoff distance plays a more important role in contributing the surface roughness of and followed by reinforcement* reinforcement Thus the SOD has the maximum contribution of 45.20% and followed by R*R of 40.94% contribution. The total sum of square and mean of square significantly contribute same as shown in table.8 Table 7 Analysis of variance for Ra Source DOF SS MS SS Contribution% MS Contribution% SOD Speed Reinforcement SOD*SOD Speed*Speed editor@iaeme.com

8 An Investigation of Machinability & Surface Integrity on Aluminium and Titanium Carbide Composite material using Abrasive water jet Machining R*R SOD*Reinforcement Speed*Reinforcement Total % 99.99% DF- Degrees of freedom, SS- Sum of squares, MS-Mean square (Variance) Table 8 Response Table for Ra Source SOD R*R R Rank Figure 6 3D Surface plot Roughness for SOD versus Speed Figure 7 3 D Surface plot roughness for SOD versus Reinforcement% Figure 8 3 D Surface plot Roughness for Speed versus Reinforcement % editor@iaeme.com

9 S. A. Puviyarasu From Figure 6 shows that an increase in Surface roughness and increase in speed SOD of the aluminium titanium carbide composite. Considering the SOD, surface roughness (Ra) does not change much, irrespective of the speed. From Figure 7 shows that initially decrease in surface roughness and gradually increase in Ra and considering increase in SOD and Reinforcement %. An increase or decrease in reinforcement % does not make much impact in Ra, when SOD is considered. Figure 8 shows that initially decrease in surface roughness and gradually increases in Ra and considering increase in SOD and Reinforcement %. Figure 9 Residual plots for RA Figure 9 shows that the normal probability plot, histogram chart, versus order charts for surface roughness values. 5. CONCLUSION The present study explored the investigation of material removal rate and surface roughness of the material aluminium and titanium carbide with design of experiments (Response surface methodology) using abrasive water jet machining. From the work, following inferences can be drawn: 1) The input process parameters of AWJM can enhance the material removal.the abrasive grain generated mechanically not only increased the MRR but also generated fine surface integrities 2) The MRR of each reinforcement material is gradually increases when increase in Standoff distance and also time reduces when increase in Standoff distance. Moreover, the Standoff distance 98.75% is the maximum contribution for MRR. When machining the material. By using small grain size of abrasive would promote to obtain larger MRR.. 3) In the case of surface roughness, the Standoff distance and reinforcement plays major significance of 45.20% and 40.94%.Since, the confirmation experiment were conducted on surface roughness as obtained response surface methodology. The optimal response valve for surface roughness 2.8µm editor@iaeme.com

10 An Investigation of Machinability & Surface Integrity on Aluminium and Titanium Carbide Composite material using Abrasive water jet Machining 4) The test results provides the greater significant on selecting the output parameters such as MRR and RA while machining the Aluminium and titanium carbide material on abrasive water jet machining and also fits the requirement of modern day applications. REFERENCES: [1] Kannan S, Kishawy H.A, Surface characteristics of machined aluminium metal matrix composites, International Journal of Machine Tools & Manufacture Vol.46,2006, [2] Chinmaya R. Dandekar, Yung C. Shin, Modelling of machining of composite materials, in: Centre for Laser-Based Manufacturing, International Journal of Machine Tools & ManufactureVol.57, 2012,pp [3] D. Sidda Reddy et al, Parametric optimization of Abrasive water jet machining of Inconel 800H using Taguchi Methodology, Universal journal of Mechanical Engineering, 2(5), , [4] Amina et al, Experimental Investigation of thermally enhanced abrasive water jet machining of hard to machine metals, CIRP journal of manufacturing science and technology, Vol 10, May [5] M. Hashish, Observation of wear of abrasive water jet nozzle materials, Journal in tribology, Vol 116 no 3, July [6] Shah R. V, Patel D. M, Abrasive water jet machining- The Review, International Journal of Engineering Research and Applications (IJERA), Vol 2 (5), September- October 2012, pp [7] Khan A.A, Haque M.M, Performance of different abrasive materials during abrasive water jet machining of glass, in: Journal of Materials Processing Technology Vol.191, 2007, pp [8] Anderson and sinn, Evaluation of the machinability of Inconel 718 under varying conditions, International journal of machine tools and manufacture, Vol 12 no 4, Jun 2012 [9] S. Muralidharan, N. Karthikeyan, Abburi Lakshman Kumar and I. Aatthisugan. A Study on Machinability Characteristic in End Milling of Magnesium Composite. International Journal of Mechanical Engineering and Technology, 8(6), 2017, pp S. A. Puviyarasu is an active researcher in the field of Materials and Industrial Engineering. He has published several International research journals. He currently pursuing his bachelors in Engineering (Mechanical Engineering), Dr N.G.P Institute of technology, Affiliated to Anna University, Chennai, India. Maid Id: mrpuvi5@gmail.com editor@iaeme.com