International Journal of Materials and Product Technology (19 papers in press)
Optimization of friction stir processing parameters to fabricate AA6063/SiC surface composites using Taguchi technique
by Manu Srivastava, Sandeep Rathee, Sachin Maheshwari
Abstract: Fabrication of metal matrix surface composites is an emerging trend of friction stir processing (FSP) applications. This research proposes production of AA 6063/SiC surface composites (SCs) using FSP. Influences of FSP process parameters viz. tool rotational speed, traverse speed and tilt angle were investigated on the distribution of reinforcement particles and mechanical properties of SCs. Experiments were designed using Taguchi technique. Optimum combinations of process parameters were determined for higher microhardness and ultimate tensile strength respectively using signal/noise ratio graph responses and analysis of variance method. Results revealed that the uniform dispersion of reinforcement particles and appreciable improvement in mechanical properties was achieved by employing optimal combinations of 1400 rpm tool rotational speed, 40 mm/min traverse speed and 2.5˚ tilt angle. About 46% enhancement in microhardness was achieved with optimal parameters as compared to base metal. Conclusions of this research clearly correlate microstructural observations with mechanical properties and reinforcement distribution.
Keywords: friction stir processing; aluminium metal matrix composites; microstructure; mechanical properties; material performance.
A comprehensive review of microstructure evolution during friction stir welding of aluminium to copper
by Tanmoy Medhi, Barnik Saha Roy, Subhash Chandra Saha
Abstract: The present review paper focuses on the various researches done in joining of aluminium and copper by friction stir welding (FSW). Being a solid state process, FSW has proven to efficiently join aluminium and copper which is extensively used in power generation, electrical and electronic industry. However, it is a challenge to achieve a good quality welded joint of aluminium and copper due to the difference in properties of both the materials. The present review paper comprehensively reports the study of microstructure and its evolution during the process. Also, an assessment of the formation of different intermetallic compounds (IMCs) during the process and the effect of various process parameters like rotational speed, tool traverse speed, the arrangement of base materials, offset and tool geometry on the IMCs and microstructure evolution is given.
Keywords: friction stir welding; FSW; aluminium; copper; microstructure; intermetallic compound; IMCs.
On the improved mechanical properties of nanoclay reinforced ABS composite for fused deposition modelling
by Vishal Francis, Prashant K. Jain
Abstract: Due to the restrictions imposed by the availability of materials in fused deposition modelling process (FDM), the achieved mechanical properties of FDM parts are limited. This scarceness leads to a critical need for improving the mechanical properties of FDM parts. The incorporation of nanoclay can effectively improve the mechanical properties of polymeric materials used in FDM. The present study investigates the FDM of clay-based polymer nanocomposite and examines the effect of dual extrusion in part fabrication. Incorporation of nanoclay demonstrated significant improvement in tensile, modulus and compressive strength as 14.5%, 21% and 24% respectively. A substantial increase in modulus and compressive behaviour was observed in hybrid parts. The developed material possesses enhanced properties compared to the virgin polymer and can be used effectively as an alternative material for FDM process. Dual extrusion technique can aid to tailor material properties as per the requirements in FDM parts.
Keywords: fused deposition modelling; dual extrusion; nanoclay; nanocomposite; grey Taguchi method.
Determination of heat transfer coefficients for large scale steel forgings quenched in polymer solutions
by Jesús Mario Luna-González, Edgar Ivan Saldana-Garza, Rafael David Mercado-Solis, Luis Adolfo Leduc-Lezama, Bradley P. Wynne
Abstract: The inverse heat conduction method is used to calculate surface heat transfer coefficients (HTCs) as a function of temperature and location during quenching of a complex geometry large steel forging in a static polymer solution. Experimental temperature-time data extracted from the piece were used as input data to calculate the HTC. The geometry was divided into seven different zones (surfaces). An individual HTC, with a high level of experimental confidence, was calculated for each zone by using the inverse heat transfer module of the commercial software DEFORM 2D/3D. These HTCs were then used to predict the through thickness cooling behaviour of the component with a high degree of replication. This method thus appears be useful for further understanding the quenching process on large steel forgings, in general, but could be critical for obtaining accurate cooling behaviour in forgings with non-simple shapes, where one HTC may not be sufficient to describe local cooling behaviour.
Keywords: inverse heat conduction problem; heat transfer coefficient; large scale forgings; quenching; polymer quenchant; computational simulation; quenching simulation; cooling curves; meshing; DEFORM 2D/3D.
Investigation into the effectiveness of cutting parameters on wear regions of the flank wear curve and associated cutting tool life improvement
by Erhan Altan, Alper Uysal, Oguz Çaliskan
Abstract: In machining operations, less tool wear and superior tool life are desired. Therefore, the effects of cutting parameters on tool life should be known and optimal cutting parameters should be chosen to reduce tool wear. In this study, the effectiveness values of cutting parameters on each wear region in the cutting tool flank wear curve were investigated to improve cutting tool service life. For this reason, some statistical methods were employed to determine them and the results were verified by experimental studies. In the initial tool wear and the rapid tool wear regions, the most effective parameter was found as the feed and the tool wear increased with increase of the feed. In the steady-state tool wear region, the effectiveness values of the cutting speed and the feed were very close to each other, but the cutting speed was determined a little more effective.
Keywords: tool life; flank wear; wear regions; turning; Taguchi method.
Parametric optimisation in Nd-YAG laser cutting of thin Ti-6Al-4V super alloy sheet using evolutionary algorithms
by A. Tamilarasan, D. Rajamani, Balasubramanian Esakki
Abstract: In this paper, genetic and simulated annealing algorithm approaches are proposed for the selection of the optimal values in efficient Nd-YAG laser cutting of thin Ti-6Al-4V super alloy sheet. The pulse width, pulse energy, cutting speed, and gas pressure are considered as process parameters. Response surface methodology based Box-Behnken design is adopted to conduct the experiments for measuring the proposed performance characteristics such as kerf deviation (KD) and metal removal rate (MRR). Quadratic regression models are developed to predict the responses using response surface methodology. Analysis of variance tests have been carried out to check the adequacy of the developed regression models. Based on the developed mathematical models, the interaction effects of the process parameters on KD and MRR are investigated. Minimising KD and maximising the MRR are considered as objectives functions. The optimal laser cutting conditions are obtained to minimise the KD and maximise the MRR in considering single and multi objective optimisation methods. Validation tests with optimal levels of process parameters were performed to illustrate the effectiveness of GA and SA algorithms. It is believed that the used algorithms provide a robust way of looking the optimum process parameters for a selected laser cutting system.
Keywords: genetic algorithm; kerf deviation; metal removal rate; MRR; Nd:YAG laser; optimisation; simulated annealing; titanium alloy.
Theoretical and experimental investigation for micro-channel fabrication using low power CO2 laser
by Arif Varsi, Abdul Hafiz Shaikh
Abstract: CO2 laser being a localised non-contact type machining process depends on the thermal and mechanical properties of a material to a great extent. The scope of this research is to study the effect of process parameters on channel profile of polymethylmethacrylate (PMMA) by CO2 laser (0-25 W). The parameters selected are beam power and scanning speed, keeping assist gas pressure constant. Using the principle of energy balance and assuming complete evaporation of molten material, an analytical model for the depth of cut is developed by considering Gaussian beam energy distribution in three-dimensional coordinate systems. Experimental results obtained at 5 mm thick plate by varying process parameters were compared with the analytical data showing good convergence with a variation of 1.83%. An attempt is made to analyse the variation of channel geometry as a function of process parameters analytically. The present model was developed with consideration of x, y and z coordinates associated with laser machining process and was validated by experimentation and 2D model available in the literature. It was observed that the proposed model shows good convergence with the experimental values. Hence, the proposed model is found to be suitable for prediction of micro-channel depth with precision.
Keywords: Gaussian beam; polymethylmethacrylate; PMMA; depth profile; channel geometry.
On the reduction of stress concentration factor in an infinite panel using different radial functionally graded materials
by Vikas Goyat, Suresh Verma, Ramesh Kumar Garg
Abstract: This work deals with a parametric study of the stress concentration factor in different functionally graded material panels having a central circular hole subjected to a uniaxial tensile, biaxial tensile and shear load. The extended finite element method along with isoparametric graded finite element material properties modelling scheme is used to evaluate the stress concentration factor. Three candidate material gradation models are tested in this parametric study and various metal ceramic functionally graded materials are also tested for stress concentration. The stress concentration factor evaluated numerically for a wide range of Young's modulus ratio and power law index are presented. It has been concluded that the low stress concentration factor can be achieved by choosing the proper material gradation model and their power law index for a fixed value of Young's modulus ratio.
Keywords: stress concentration factor; SCF; power law FGM; sigmoid FGM; functionally graded material; extended finite element method; XFEM; circular hole.
A theoretical procedure for the stress state assessment of hyper-static crankshafts
by Sergio Baragetti
Abstract: Crankshafts with many rods and crankpins for mechanical and industrial applications can be designed with first-order-approximation theoretical procedures in the literature. Numerical boundary element method (BEM) or finite element method (FEM) procedures can be used, with the latter models having a 3D tetrahedral, wire beam or hexahedral finite elements. To the best of the author's knowledge, the literature does not contain accurate evaluations of hyper-static reactions at the restraints of a crankshaft with four crankpins and five supports. The principle of virtual work is implemented to allow calculation of the reactions at the bearings of the shaft and to determine the internal actions (bending, torsion, shear and axial force) for each section of the shaft. The developed procedure does not give better results than a numerical BEM or 3D FEM code, but it is less expensive and less time consuming when implemented in a mathematical commercial code. Furthermore, the procedure gives results that have a better approximation with respect to the theoretical literature models. The theoretical model was validated through comparison with the results of a finite-element linear beam model developed using a commercial FEM code.
Keywords: machine design; performance enhancement; fatigue design; four-rod crankshaft; theoretical model.
Experimental and mathematical evaluation of thermal and tensile properties of friction stir welded joint
by Ratnesh Kumar, Bhabani Bora, Somnath Chattopadhyaya, Grzegorz Krolczyk, Sergej Hloch
Abstract: The aim of this experiment is to develop a mathematical model of friction stir welded joint of aluminium alloy 6061-T6 for correlating the process parameters (rotational speed, welding speed) with output responses (maximum process temperature, yield strength, ultimate tensile strength and % elongation). This developed model will establish an empirical relationship between the modelled values and experimental values. Experiments of AA 6061-T6 FSW butt joints were carried out by using a 'full factorial' design. Analysis of variance and scatter diagram were utilised to assess the significance of the factors and adequacy of the models developed for response variables. The optimum values of output responses, i.e., Tmax, YS, UTS and %E, were found as 417.98°C, 123.92 MPa, 134.42 MPa and 12.07, respectively, at optimum welding parameters (1,000 rpm and 40 mm/min). The influence of FSW process parameters on temperature distribution as well as tensile properties has been analysed in this study.
Keywords: friction stirs welding; full factorial design; ANOVA; genetic algorithm.
Wear characteristics of a combustion liner for power generation gas turbine
by Ahmad Afiq Pauzi, Salmi Mohd. Yunus, Shuib Husin, Mariyam Jameelah Ghazali, Wan Fathul Hakim W. Zamri
Abstract: Wear is the main degradation of the combustor components in gas turbine power generation. One of the most vital components in a gas turbine is the combustion liner which is often observed with severe wear damage. In this study, the combustion liner was made from Hastelloy X (a nickel-based superalloy material). The degradation generally occurred at the mating surfaces of the combustion liner which consisted of the fuel nozzle and a transition piece. The purpose of this study was to determine and characterise the dominant wear mechanisms at two different contact surfaces (connected to stainless steel and Nimonic 263) after being exposed to 8,000 hours of run time at high temperature and vibration. The worn surfaces were analysed and the wear mechanism was discussed.
Keywords: wear; combustion liner; power generation; gas turbine.
Multi-criteria selection of optimal welding parameter in MMAW hardfacing using MOORA method coupled with PCA
by Abhijit Saha, Subhas Chandra Mondal
Abstract: Multi-criteria decision making approach is one of the most demanding tools for solving the intricate optimisation problems in the area of welding. Hardfacing is widely used to improve the wear and corrosion resistance of components. The process of hardfacing should be aimed at achieving a strong bond between the deposit and the base metal. Therefore, it is very important for the selection of process parameters to improve product qualities in hardfacing. This paper introduces the multi-objective optimisation of manual metal arc welding (MMAW) process parameters in hardfacing with Nano-technology based electrode using MOORA (multi-objective optimisation on the basis of ratio analysis) method coupled with PCA (principal component analysis). The paramount process variables have been considered to undergo experiments such as welding current, arc voltage and welding speed; response parameters incorporate weld bead width, reinforcement and bead hardness, respectively. Finally, confirmation test has been carried out to validate the experiment result.
Keywords: hardfacing; multi-objective optimisation; manual metal arc welding; MMAW; MOORA; principal component analysis; PCA.
Special Issue on: Advances in Measurement Science and Technology
Non-contact roundness measurement with air gauges: simulation studies
by Radomir Majchrowski
Abstract: The article presents the results of simulation-based analysis of non-contact roundness measurement of inner cylindrical surfaces. The method is based on the reference measurement with air gauges. The simulation tests were conducted to evaluate the influence of certain parameters on the final measurement results, including the harmonic analysis (up to 15th harmonics). The investigations were aimed to the assessment of influence of particular measurement errors, like the error of the measuring slot, or the non-orthodox position of the measuring head, on the final result of the roundness measurement. These studies results are useful not only in this particular application, but generally in process of design of the non-contact roundness measurement instrument that using air gauges.
Keywords: air gauge; roundness; simulation studies; matlab.
Investigations of Performance Parameters in NFMQL Assisted Turning of Titanium Alloy Using TOPSIS and Particle Swarm Optimization Method
by Munish Gupta, P.K. Sood, Gurraj Singh, Vishal S. Sharma
Abstract: This paper deals with the multi-response optimization of process parameters in nano-fluid based minimum quantity lubrication (NFMQL) assisted turning of titanium (grade-2) alloy. The multi-response optimization methods included are multi-criteria decision making tool i.e., TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) approach and particle swarm optimization (PSO) method. The turning experiments were performed by varying cutting speed (Vc, 200 mm/min 300 mm/min), feed rate (f, 0.10 mm/rev 0.20 mm/rev), approach angle (ϕ, 60
Keywords: ANOVA; Machining; Optimization; PSO; Titanium alloy; TOPSIS.
AIR GAUGE BACK-PRESSURE UNCERTAINTY ESTIMATION FOR THE ADVANCED TEST RIG
by Czeslaw Jermak, Miroslaw Rucki, Michal Jakubowicz
Abstract: In the paper, the uncertainty estimation of the back-pressure measurement in the advanced experimental rig equipped with the electronic devices, pressure transducers, precise step motors is discussed. The proposed apparatus was used in case of some accurate and dedicated applications that required experimental examination of the selected air gauges to confirm their capability. The advanced experimental rig for the air gauges properties assessment is a system consisting of many elements, each of them adding some uncertainty to the final measurement result. The main sources of uncertainty are identified as following: operator, environment, mechanical unit, electronic unit, pneumatic unit, data processing. Assessment of the back-pressure uncertainty was performed using the method A. The series of repetitions revealed that the uncertainty of the back-pressure indication depends on characteristics (measuring range and sensitivity) of the actually examined air gauge. Additional attention was paid to the flow instability in the measuring chamber that cause the instability of the back-pressure measurement results
Keywords: air gauge; uncertainty; back-pressure; air flow; calibration.
Barkhausen noise signal analysis of heat treated samples at various magnetizing frequencies
by Ashish Srivastava, Harikishor Kumar, Mohd.Zaheer Khan Yusufzai, Meghanshu Vashista
Abstract: Signal processing of magnetic Barkhausen noise was performed to reveal the useful information content of the signal which would otherwise difficult due to stochastic nature of the signal. Magnetic Barkhausen noise signal was measured from different heat treated steel samples which were further processed to investigate the effect of heat treatment on Barkhausen noise signal. The dependence of Barkhausen signal upon magnetizing frequency was also discussed in terms of rms value of Barkhausen noise envelope. Variation in the rms value of the Barkahusen noise profile with magnetizing frequency and mechanical properties was explained using micromagnetic theory. The present study shows that Magnetic Barkhausen noise signal depends upon mechanical properties as well as on magnetizing frequency which needs to be optimized in order to use magnetic Barkhausen noise as a characterization tool.
Keywords: Magnetic Barkhausen noise; Heat treatment; Domain wall; Magnetising frequency; Root mean square; Eddy current; Signal processing; Microhardness; Magnetization;Characterization.
Special Issue on: Recent Trends in Design of Nanocomposites Experimental and Theoretical Approaches
A Predictive Modeling of Nanocomposite Coating Microhardness Based on Extremely Randomized Trees
by Hai Guo, Zhao Jingying, Li Xiaoniu
Abstract: Nanocomposite coating is a coating made of particles whose sizes are of nanoscale. The coating has superior performances. The microhardness of the coating is an importance parameter. Currently, experimental method is mainly adopted in the coating's microhardness and performance research, with high research cost and long time period. In this paper, the content of the nano-particles in the plating liquid, current density, duty ratio, addition of additives and ultrasonic power are set as inputs; the micro hardness of the nanocomposite coating is set as output. Extremely randomized trees (ERT) is used to establish a strong prediction model. The research results show that the correlation coefficient of the ERT model is 0.9447, which mean absolute error is 0.0007 and that the root mean squared error is 0.0013. The error between the predictive value and experimental value is small. The prediction performance is the ERT model is superior to that of the single models such as linear regression, Back-Propagation neural network, Radial basis function neural network, support vector regression and Multi-Layer Perceptron etc. and other ensemble learning methods such as random forest, bagging-decision stump and stochastic gradient boosting etc. ERT model can be used for predicting the microhardness of nanocomposite coating, providing an efficient and highly reliable method for new material performance prediction.
Keywords: Nanocomposite coatings; prediction model; extremely randomized trees; ensemble learning.
Influence of solutionizing temperature and time on spherodization of the silicon particles of AMNCs
by Mohsen Ostadshabani, Fatemeh Heydari
Abstract: Perhaps it could be said that among the casting alloys of aluminum, Al-Si-Mg alloys have the highest consumption rate in different industries. Because these alloys have good castabilities and perfect mechanical properties in heat treated conditions, good wear resistance, good weldability, and low thermal expansion. In this research the effect of temperature and time of heat treatment on spherodization of silicon particles was thoroughly investigated in casting samples in semi-solid state of Aluminum matrix nano composites, and it was found that heat treatment leads to fracture and spherodization of silicon particles and by increasing solutionizing time these siliconparticles cling to each other and grow. It was determined that 540 degree centigrade is a suitable temperature for solutionizing in 4 hours.
Keywords: Heat treatment; Nano; A356; Silicon; Composite.
Analysis for electromagnetic performance of PM motor with different metal Nano-material bars
by Likun Wang
Abstract: With the appearance of high-performance permanent magnet (PM) materials as well as the development of computer technology and Nanotechnology and electricity machine theory, scholars have done a lot of research on the self-starting permanent magnet synchronous motor and have made many achievements. Although the starting permanent magnet synchronous motor has many advantages compared with the induction motor, there are also many problems. Since the self-starting motor needs to realize the self-starting and maintaining the synchronous speed operation, its rotor structure design is more complex. The rotor requires the starting winding and the magnets coexist, so there is "space competition", especially the small motors with high power density. Nowadays, Nano-materials are applied on a motor to improve its electromagnetic performance. In this paper, the electromagnetic performance of a PM motor with different metal Nano-material bars is researched by finite element analysis (FEA). In this paper, the electromagnetic performance of a PM motor is researched when the rotor bars are with different sizes metal Nano-palladium by FEA. The magnetic field distribution, the dynamic speed and torque variation, and the eddy current losses are analyzed respectively.
Keywords: permanent magnet materials; Nano-material; performance; synchronous motor.