Papers Posted on - Aug / 2013


Author Name S. Assarzadeh and M. Ghoreishi
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.03
Paper Title Statistical Investigation into the Effects of Electro-Discharge Machining Parameters on WC/6%Co Composite-Part 1: Modeling through Response Surface Methodology (RSM)
Abstract
In this two-part research, a unified approach is presented to model and optimize the electro-discharge machining (EDM) parameters on WC/6%Co using response surface methodology (RSM) and desirability function (DF) concept. In the first part, four controllable parameters, viz., discharge current (A), pulse on-time (B), duty cycle (C), and average gap voltage (D) have been selected as the input variables to evaluate the process performance in terms of material removal rate (MRR), tool wear rate (TWR), and arithmetic mean surface roughness (Ra) as the performance characteristics. The modeling phase begins applying face-centered central (FCC) composite design to plan and analyze the experiments in accordance with the RSM. For every response, the significant forms of influential parameters were properly identified conducting a comprehensive analysis of variance (ANOVA) at 1, 5, and 7% level of significance. It has been revealed that all the direct effects of input parameters are extremely momentous affecting both the MRR and TWR. Moreover, the pure quadratic effect of duty cycle (C2), the reciprocal effects of discharge current with pulse on-time (A×B), duty cycle (A×C), and gap voltage (A×D), as well as the interaction amongst the pulse on-time with duty cycle (B×C) were also reached to be important terms affecting the MRR. The TWR measure behaves the same way, however, it exhibits a more nonlinear mathematical form containing the second order effect of discharge current (A2) as an additional important term. On the other hand, for the Ra, the only significant parameters are the main effects of the first two inputs (A and B) plus the interactions of current with pulse on-time (A×B) and with gap voltage (A×D). The results indicate that the suitably proposed step-by-step implemented approach can substantially elucidate the highly multifaceted behavior of the chosen grade WC-Co under different EDM conditions providing a reliable platform to both navigating the operational region and seeking for optimal working circumstances confidently.
Keywords
Analysis of variance (ANOVA), Electro-discharge machining (EDM), Face centered central (FCC) composite design, Process modeling, Response surface methodology (RSM), Tungsten carbide cobalt composite (WC-Co).
Author Name Alain Kusmoko and Alan Crosky
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.02
Paper Title Wear Mode Map Evaluation of Induction Hardened 4140 and Carburised 8617H Steels on 1040 Steel
Abstract
This study was undertaken to evaluate the likely effect on the wear rate of changing the pinion material in a rack and pinion steering box from carburised SAE-AISI grade 8617 H steel to induction hardened SAE-AISI grade 4140 steel. Accordingly, pin-on-disc unlubricated wear tests were conducted using carburised 8617 H pins and through hardened 4140 pins. The surface hardness of the pins was approximately 60 HRC for both materials. The discs were made of SAE-AISI grade 1040 steel through hardened to a hardness of 45 HRC. The tests were conducted using a load of 2.2 kg and a rotational speed of 60 rpm and also under a load of 28.5 kg and a speed of 99 rpm. The results showed that both the pins and the discs wore more rapidly when the tests were carried out with 4140 pins. The data was evaluated using a wear mode map developed by Lim, Ashby and Brunton. This indicated that the wear mode was mild delamination wear at the lower load and speed but severe oxidational wear for higher load and higher speed.
Keywords
Wear Mode Map, Severe and mild oxidational wear, Rack and Pinion, 8617H steel, 4140 steel and 1040 steel
Author Name Alain Kusmoko,Druce Dunne, Huijun Liand David Nolan
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.01
Paper Title Deposition of Stellite 6 on Nickel Superalloy and Mild Steel substrates with Laser Cladding
Abstract
Stellite 6 was deposited by laser cladding of two different steel substrates (nickel superalloy and mild steel). The chemical compositions and microstructures of these coatings were characterized by atomic absorption spectroscopy, optical microscopy and scanning electron microscopy. The microhardness of the coatings was measured and the wear mechanism of the coatings was examined using a pin-on-plate (reciprocating) wear testing machine. The results showed less cracking and pore development for Stellite 6 coatings applied to the mild steel (MS) substrate. Further, the Stellite coating on mild steel was significantly harder than that deposited on the superalloy. The wear test results showed that the weight loss for the coating on mild steel was significantly lower than for the nickel superalloy substrate. It is concluded that the lower hardness of the coating on the nickel superalloy, together with the softer underlying substrate structure, markedly reduced the wear resistance of the Stellite 6 coating
Keywords
Laser cladding, Stellite 6 coating, friction and wear, nickel superalloy and mild steel
Author Name S. Assarzadeh and M. Ghoreishi
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.04
Paper Title Statistical Investigation into the Effects of Electro-Discharge Machining Parameters on WC/6%Co Composite-Part 2: Parametric Analysis and Optimization through Desirability Function (DF)
Abstract
Following the first part, in the second part, a complete parametric analysis including main effects along with the joint effects of significant two-way interactive factors are performed over each previously developed response (MRR, TWR, and Ra). It has mainly been revealed that all the responses are affected by the rate and extent of discharge energy but in a controversial manner. The MRR increases by either enhancing electrical discharge density or rising sparking frequency. Low TWRs can essentially be established by a combination of low current levels with prolonged pulse on-times or longer pulse on-times with smaller duty cycles. Less rough surfaces are achievable via a blend of either low current intensity with shorter pulse on-time or low current level with higher gap voltage. Moreover, to locate the exact numerical values of optimal settings, a multi-objective optimization technique based on the concept of desirability function was then applied to the response equations to simultaneously find optimum points of input parameters capable of producing the highest possible amount of MRR and lowest amounts of TWR and Ra within the investigated process domain in a compromise manner. The obtained predicted optimal results were then interpreted and verified experimentally to compute confirmation errors. The values of relative validation errors, all being found to be quite satisfactory (about 11% at the worst case); proves the effectiveness and reliability of suggested approach in optimizing the highly interconnected EDM parameters on WC-6%Co composite.
Keywords
Electro-discharge machining (EDM), Desirability function, Multi-objective optimization, Parametric analysis, Tungsten carbide cobalt composite (WC-Co)
Author Name Manoj Kumar Rath
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.05
Paper Title Resonance Characteristics of Woven Fiber Composite Flat Panels in Hygrothermal Environment
Abstract
The present study deals with the parametric resonance characteristics of woven fiber laminated composite plates with uniform rise in temperature and moisture concentration. The effects of various parameters like increase in number of layers, ply-orientations of composite plates at elevated temperatures and moisture concentrations on the principal instability regions are studied using finite element method. The first-order shear deformation theory is used to model the composite plates under hygrothermal environment, considering the effects of transverse shear deformation and rotary inertia. The results on the dynamic stability studies of the woven fiber laminated composite plates with different parameters suggest that the onset of instability occurs earlier and the width of dynamic instability regions increase with rise in temperature and moisture. The instability occurs earlier with increase in temperature and moisture for different parameters.
Keywords
Dynamic stability; Excitation frequency; Hygrothermal Environment; Woven fiber
Author Name K.Kishor Kumar Dr. K.Raja Narender Reddy S.Sripathy
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.06
Paper Title Evaluation OF Flexural and Water Absorption Properties of Short Kenaf Fiber Reinforced Green Composites
Abstract
The present work study flexural behavior and water absorption properties of short Kenaf fiber reinforced composites. The fibers are chemically treated in 2% NaOH solution at room temperature. Short fibers of 4mm and 8 mm are used in the present work. The composite lamina is prepared by hand molding using isopthalic polyester resin. Flexural test and water absorption tests are carried out as per ASTM standards. The flexural strength and flexural modulus and water absorption behaviour of composite lamina are evaluated. Effect of Fiber surface Treatment on flexural properties and water absorption behaviour is also observed. .The Flexural Strength is increased by 13.8%, 12.8%, and 1.6% for Kenaf T-4 mm laminate, Kenaf T-8 mm laminate, Kenaf UT-4 mm laminate respectively when compared to resin lamina. . But it is observed that the Flexural Strength is decreased by 4.4% for Kenaf UT-8mm laminate when compared to resin lamina. Surface treatment of fiber had a significant effect on fiber/matrix adhesion due to this there is an increase in Flexural strength. Water Absorption capacity is less for Kenaf T-8mm laminate when compared to other composite laminates but it is high when compared to pure resin laminate..
Keywords
Natural fiber reinforced composites, Polyester Isopthalic resin, Flexural strength, Water Absorption capacity.
Author Name K. Srinivasa Vadayar, S. Devaki Rani, G. Sri Satya, V.V. Bhanu Prasad
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.07
Paper Title Production and Characterization of Titanium Matrix Composites by VHP Route
Abstract
Discontinuous particulate reinforced metal matrix composites (MMC)’s due to their low cost, ease of manufacturing and relatively good isotropic mechanical properties, form one of the major and important applicative class of composite materials. Titanium being one among the matrix materials (other important ones including Al, Mg, Cu and their alloys) widens its scope of usage due to its high strength to weight ratio, high stiffness, good corrosion resistance and high creep resistance. In the present work discontinuously reinforced titanium matrix composites (TMCs) were synthesized by using CP Ti powder (13µm) and B4C powder of varying particle sizes (165µm, 49µm, 8µm) through powder metallurgy. The blended powder were consolidated by VHP at 1000˚C for 1hr. XRD analysis was carried out to conform the extent of the reaction and the types of phases present. Microstructural analyses were carried out. The strength of the composites were evaluated by the three point bend test. The test revealed that the composites have high flexural strength with respect to unreinforced titanium. The fractography of the bend tested samples was carried out using SEM which revealed a mixed mode of fracture for the composites
Keywords
Titanium, boron carbide, Titanium matrix composite, XRD, Three point bend test.
Author Name Ziauddin Khan and H. A. Pathak
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.08
Paper Title Development of Aluminium Wire as an UHV Compatible Demountable Seal
Abstract
Aluminium and Copper wire-seals were fabricated and characterized as ultra-high vacuum (UHV) demountable wire-seals for large sized non-circular openings. A vacuum system used to measure integrated helium leak rate over the whole circumference of the wire-seal and the wire compression at particular compression force is described. The results show that the leak rate of the order of 1 × 10 – 10 mbar l/s can be achieved by applying the force per unit length of 258 kN/m to aluminium wire-seal with compression of 25 %, while to obtain the same order of leak rate in copper wire-seal, the force per unit length is 415 kN/m at the compression of 44 %.
Keywords
Demountable, Wire-seal UHV, Compression
Author Name R.Keshavamurthy, Padmanav Rashmirathi, A.R.Vinod, C.K.Srinivasa, P.V.Shashikumar
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.09
Paper Title Optimization of Process Parameters for Direct Metal Deposition of H13 tool Steel
Abstract
This paper focuses on optimization of process parameters for direct metal deposition of H13 tool steel using Taguchi method of experimental design. The effect of laser power, laser scan speed and powder flow rate on hardness of the deposits have been investigated. L9 orthogonal array of Taguchi technique was used for experimental trials. The optimum process parameters have been identified to achieve maximum hardness. Significant process parameters were identified from the analysis of variance (ANOVA). Further, verification experiment has been carried out to confirm the performance of optimum process parameters.
Keywords
Direct Metal Deposition, Taguchi, Hardness, Laser power, Powder flow rate, Scan speed.
Author Name Pragyan Paramita Mohanty , S.S Mahaptra
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.10
Paper Title Design of office Chair: A Quality Function Deployment Approach
Abstract
This paper employs a quality function deployment (QFD) methodology to translate customer requirements into design characteristics to improve the design of an office chair. A factor analysis has been carried out on the responses obtained from a cross sectional survey directed at users through a set of questionnaires. It has been obtained that three factors with twenty two items are loaded with a threshold value above 0.7. Finally, quality function deployment is used to extract important design characteristics satisfying the customer requirements
Keywords
Factor Analysis; Quality Function Deployment (QFD); House of Quality
Author Name Ritanjali Sethy, C.K. Biswas and Shailesh Dewangan
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.11
Paper Title Multi Response Optimisation for Correlated Responses in EDM using Principal Component Analysis
Abstract
This study presents a new method to determine multi-objective optimal condition using Principal Component Analysis (PCA) based on Grey Relational Analysis (GRA) Method for Characteristics as Material Removal Rate (MRR), Tool Wear Rate (TWR) and Surface Roughness (Ra) on Electrical Discharge Machining (EDM).In this paper, an attempt has been made to machining the AISI P20 tool steel by using cylindrical copper electrode perform on EDM. A well-designed L27 orthogonal array based on the Taguchi method were conducted on input parameters as current, pulse on time, up-time, working time and inter electrode gap.
Keywords
Electrical Discharge Machining (EDM), AISI P20 tool steel, PCA, PCA-based GRA..
Author Name Gunti Rajesh, Atluri V. Ratna Prasad
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DOI http://dx.doi.org/10.11127/ijammc.2013.07.12
Paper Title Effect of Fibre Loading and Successive Alkali Treatments on Tensile Properties of Short Jute Fibre Reinforced Polypropylene Composites
Abstract
The use of natural fibres like flax, hemp, jute, kenaf, etc. as replacement to man made fibres in fibre-reinforced composites have increased now a days due to advantages like low density, low cost and biodegradability. But the natural fibres have poor compatibility with the matrix and they have relatively high moisture sorption. Therefore different chemical treatments are done on the fibres to modify the surface. In this research, short jute fibre reinforced polypropylene composites have been developed by injection molding technique with varying parameters like fibre loading (0%, 5%, 7.5%, 10%, 12.5% &15% by weight) and fibre condition (untreated, NaOH treated followed by bleaching with H2O2) at constant fibre length of 3mm. Then these composite specimens are tested for tensile strength. The results showed that tensile strength increases with increase in the fibre loading and also with increase in %NaOH (5%, 10% & 15%) concentration in the treatment followed by bleaching with H2O2. However after 10% fibre loading with 10%NaOH concentration in the fibre treatment, the strength decreased again. There was small increase in the strength of composite with treated fibres compared to composite with untreated fibres. The modulus of the composite with treated fibres has increased considerably when compared to plain PP and untreated fibre reinforced PP composite
Keywords
Bleaching, Composite, Natural Fibre, Tensile Properties