Forthcoming articles

 


International Journal of Materials and Product Technology

 

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International Journal of Materials and Product Technology (23 papers in press)

 

Regular Issues

 

  • Theoretical procedure for the stress state assessment of hyper-static crankshafts   Order a copy of this article
    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 of hexahedral finite elements. To the best of the authors 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: Four-rod crankshaft; Theoretical model; Machine design; Performance enhancement; Fatigue design.

  • Experimental and mathematical evaluation of thermal and tensile properties of friction stir welded joint   Order a copy of this article
    by Ratnesh Kumar, Bhabani Bora, Somnath Chattopadhyaya, Grzegorz Krolczyk, Sergej Hloch 
    Abstract: The aim of this experimental work is to develop a mathematical model of friction stir welded joint of aluminum 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 provides an empirical relationship between the modeled values and experimental values. Experiments of AA 6061-T6 FSW butt joint were carried out using the Full Factorial design of experiment. Analysis of variance and scatter diagram has been employed to assess the significant effect of the factors and the adequacy of the models developed for the response variables. The optimum values of output responses i.e. TMax, YS, UTS and % E are found as 417.98
    Keywords: Friction Stir Welding; Full Factorial Design; ANOVA; Genetic Algorithm.

  • A comprehensive review of microstructure evolution during friction stir welding of aluminium to copper   Order a copy of this article
    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; Aluminium; Copper; Microstructure; Intermetallic compounds.

  • On the improved mechanical properties of nanoclay reinforced ABS composite for Fused Deposition Modelling   Order a copy of this article
    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. Multiobjective optimization, grey relation based Taguchi technique was used to determine the optimal processing temperature and clay content. Mechanical characterisation was performed on the nanocomposite developed and hybrid parts fabricated by dual extrusion. Microstructure investigation was carried out to examine the interaction between nanofiller and polymer for the developed filament and to study the fracture surface morphology. 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. Hybrid parts demonstrated an increase in modulus as 70%, 94.8% and 147.8% for transverse, boundary and longitudinal reinforcement respectively along with an increase in compressive strength. The microstructure examination revealed that nanocomposite parts have fewer voids compared to ABS specimens due to better neck formation between the rasters. 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   Order a copy of this article
    by Jesús Mario Luna-González, Edgar Ivan Saldana-Garza, Rafael David Mercado-Solís, Luis Adolfo Leduc-Lezama, Bradley 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   Order a copy of this article
    by Erhan Altan, Alper Uysal, Oguz Caliskan 
    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. The experiments were performed by turning of AISI 1040 carbon steel with uncoated WC (Tungsten Carbide) cutting tools at different cutting speeds, feeds and depths of cut. 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. After the most effective cutting parameters on all tool wear regions were determined, validation experiments were conducted by considering these results to increase tool life during turning AISI 1040 carbon steel and AISI 4140 alloy steel. As a result, significant improvements on the tool life were obtained by properly choosing the cutting parameters for each cutting tool wear region.
    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   Order a copy of this article
    by A. Tamilarasan 
    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 to measure 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 provides a robust way of looking the optimum process parameters for a selected laser cutting system.
    Keywords: Genetic algorithm; kerf deviation; metal removal rate; Nd:YAG laser; optimization; simulated annealing; titanium alloy.

  • THEORETICAL AND EXPERIMENTAL INVESTIGATION FOR MICRO-CHANNEL FABRICATION USING LOW POWER CO2 LASER   Order a copy of this article
    by Arif Varsi, Abdul Hafiz Shaikh 
    Abstract: CO2 laser being a localized 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 analyze 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; PMMA; depth profile; channel geometry.

  • On the Reduction of Stress Concentration Factor in an infinite panel using different radial functionally graded materials   Order a copy of this article
    by Vikas Goyat, Suresh Verma, R.K. 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 Youngs 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 Youngs modulus ratio.
    Keywords: Stress Concentration Factor; Power Law FGM; Sigmoid FGM; Extended Finite Element Method; Hole.

  • Wear Characteristics of a Combustion Liner for Power Generation Gas Turbine   Order a copy of this article
    by Ahmad Afiq Pauzi, Mariyam Jameelah Ghazali, Salmi Mohd Yunus, Wan Fathul Hakim W. Zamri, Shuib Husin 
    Abstract: Wear is the main degradation of combustor components for power generation gas turbine. The occurrence of wear damage was observed on a combustion liner, which is one of the vital components in the gas turbine. The combustion liner is made from Hastelloy X (a nickel based superalloy material). The worn surface generally occurred at the mating surfaces of combustion liner. In the gas turbine, the combustion liner is mating to four different components, which are fuel nozzle, cross fire tube, flow sleeve and transition piece. The purpose of this study is to determine and characterise the dominant wear mechanisms at three different mating surfaces (connected to a stainless steel, Nimonic 263 and carbon steel) after being exposed to 8,000 running hours 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   Order a copy of this article
    by Abhijit Saha, Subhas Mondal 
    Abstract: Multi-criteria decision making approach is one of the most demanding tools for solving the intricate optimization problems in the area of welding due to its capability of solving the complex optimization problems in fabrication process. Hardfacing is widely used to improve the wear and corrosion resistance of components exposed to severe service conditions, thus to extend their service life. The process of hardfacing should be aimed at achieving a strong bond between the deposit and the base metal with a high deposition rate. Therefore, it is very important for the proper selection of process parameters to improve product qualities in hardfacing. This paper introduces the multi-objective optimization of manual metal arc welding (MMAW) process parameters in hardfcing with Nano-technology based electrode using MOORA (multi-objective optimization 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. Taguchis (L25) orthogonal array has been used to perform the experimental runs. Finally, confirmation test has also been carried out with the optimal welding process parameters to validate the experiment result. Weld quality was considerably improved based on the proposed model.
    Keywords: Hardfacing; Multi-objective optimization; Manual metal arc welding; MOORA; Principal component analysis.

  • Methodology for database development for electro discharge boring of aerospace material   Order a copy of this article
    by Sudhanshu Kumar, Harshit K. Dave, Keyur P. Desai 
    Abstract: In the present investigation, boring of an aerospace material (Inconel 718) is performed on electro discharge machine. Boring operation of predrilled circular cavity is achieved using tool movement on radial path during EDM process. The actuation of tool electrode is guided and controlled in such a way that it moves on a radial path with an angular increment of five degree from previous path. Using Taguchi design of experiment and application of multiple regression equations, a database is generated for the selection of suitable combination of process parameters for boring operation in EDM process. The criterion of creating the database for proper selection of parameters is to minimise the overcut while maintaining the surface roughness within the specified range during boring operation. In this methodology, the parameters that have lesser influence on surface roughness are identified and then their levels are suitably chosen for minimum overcut generation. Remaining factors levels are varied in such a way that the surface roughness will remain within the specified range. This type of technological database will be very useful for application in the future, as it will provide direct selection of appropriate combination of parameters for boring of Inconel 718 using EDM process.
    Keywords: boring; overcut; surface roughness; Inconel; radial tool movement; electro discharge machining; EDM.
    DOI: 10.1504/IJMPT.2018.10010755
     
  • Effect of TiO2 enriched fluxes on the bead geometry, grain size and hardness in submerged arc welds   Order a copy of this article
    by Joydeep Roy, Ram Naresh Rai, Subhash Chandra Saha 
    Abstract: This work is mainly concerned about the influence of titanium dioxide powder addition into flux on the bead geometry, grain size, and hardness in submerged arc weld of low alloy steel plates. Titanium dioxide powders were mixed with the commercial fluxes in a different proportion of 2.5, 5, 7.5, 10 and 12.5%. The welding process parameters were kept constant for different welding conditions. Bead geometry parameters show a significant improvement due to the titanium dioxide addition. 5% of titanium dioxide enrichment was showing the best result for the bead geometry parameters. Nucleation of the acicular ferrite and grain refinement of weld metal (WM) microstructure has been observed with the enrichment of titanium. Average grain size of ferrite and pearlite decreases with the increase of titanium content. Phase analysis of WMs shows that the ferrite% increased and pearlite% decreased with respect to titanium content. But, the increase of titanium content was not showing any clear trend on the hardness profile of weldments.
    Keywords: SAW; bead geometry; phase analysis; grain size; hardness.
    DOI: 10.1504/IJMPT.2018.10010769
     
  • Application and anti-bacterial performance evaluation of liquid glass coating   Order a copy of this article
    by Bingjie Xiao, Ayman Ibrahim, Xiao Huang, Rong Liu 
    Abstract: Liquid glass (LG) coating, supplied by Liquid Glass Shield Company, is capable of enhancing the wear resistance of surfaces without altering the surface features. Additionally, the coating contains ethanol that acts as an anti-microbial agent. In this study, LG is deposited on nickel substrate to investigate its ability to impede bacterial growth. The coating is applied using a spin coater and followed by a furnace curing process. The coating is then tested for bacterial growth through the deposition of a known type of bacteria onto the cured coating surface. The liquid glass coating has shown enhanced anti-bacterial ability when compared to bare nickel surface. However, the anti-bacterial ability of LG is slightly lower than that of brass alloys.
    Keywords: liquid glass coating; anti-bacterial performance; E.coli colony-forming unit; nickel; brass; benzalkonium chloride; sodium pyrithion.
    DOI: 10.1504/IJMPT.2018.10010773
     
  • Experimental design of a folded-structure energy-absorption system   Order a copy of this article
    by H. Baruh, E.A. Elsayed 
    Abstract: This paper describes the design and analysis of an energy-absorption-system container made of chevron-pattern folded paper for the purpose of encasing supplies to be dropped from moving aircraft without using a parachute. A mathematical model of the energy absorption system is developed. The constitutive properties of the system are ascertained experimentally, and the system is tested by dropping containers with different types of cargo and from the different altitudes and aircraft speeds without a parachute. Test results in a laboratory and actual drop tests from moving aircraft demonstrate that this energy-absorption system manufactured using the paper-folding machine, built at the Rutgers University, absorb the impact energy of the drop and protect the cargo from the collision forces that are encountered when the dropped container impacts the ground and tumbles. It is shown that the design can successfully protect items with different fragilities inside containers dropped from different altitudes up to 30 m with aircraft speeds up to 70 KIAS.
    Keywords: folded-structures; energy-absorption; freedrop; chevron structure; honeycomb structures; impact energy; cushion; isotropy.
    DOI: 10.1504/IJMPT.2018.10010777
     
  • Multi-objectives optimisation of PU foams on acoustic performance by using design of experiment   Order a copy of this article
    by Shuming Chen, Yang Jiang, Dengfeng Wang, Jing Chen 
    Abstract: The main objective of this study was to obtain an optimal formulation of PU foams with improved acoustic properties by using design of experiment (DOE). With the aim to obtain an efficient acoustic material, the PU foams formulation can be optimised successfully by adjusting the content of various additive components in this experiment. The experiments were conducted with four controllable three-level factors and two target objectives, and Taguchi's orthogonal array L9(34) had been chosen. The various additive components were: water (3.8-4.8 part by weight), tri-ethanolamine (TEA, 2-3 part by weight), HCFC-141b (4-6 part by weight) and A33 (0.9-1.1 part by weight). Sound absorption coefficient and transmission loss were both chosen as target objectives. The best formulation that optimised the acoustic properties of PU foams were determined by analysis of variance (ANOVA). From the results, the most significant factor affecting the experimental design objectives was identified.
    Keywords: optimisation; orthogonal array; sound absorption coefficient; transmission loss.
    DOI: 10.1504/IJMPT.2018.10010783
     

Special Issue on: Advances in Measurement Science and Technology

  • Non-contact roundness measurement with air gauges: simulation studies   Order a copy of this article
    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   Order a copy of this article
    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   Order a copy of this article
    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   Order a copy of this article
    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   Order a copy of this article
    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   Order a copy of this article
    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   Order a copy of this article
    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.