Mohsen Shakeri - Academia.edu (original) (raw)

Papers by Mohsen Shakeri

Research paper thumbnail of A Numerical Simulation of Vanadium Redox Flow Batteries

International journal of engineering. Transactions A: basics, 2019

Research paper thumbnail of Application of Particle Swarm Optimization in Computer Aided Setup Planning

INTERNATIONAL CONFERENCE ON ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES (AMPT2010), 2011

Research paper thumbnail of Computer Aided Setup Planning Using Tolerance Analysis for Prismatic Components

INTERNATIONAL CONFERENCE ON ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES (AMPT2010), 2011

Research paper thumbnail of Fixture design concept for high-product-mix and extremely low-repetitive machining center work

Research paper thumbnail of Effects of operating parameters on performance of a single direct methanol fuel cell

Thermal Science, 2010

In this study the ef fect of var i ous op er at ing con di tions on 10 cm ×10 cm ac tive area of ... more In this study the ef fect of var i ous op er at ing con di tions on 10 cm ×10 cm ac tive area of in-house fab ri cated di rect meth a nol fuel cell was in ves ti gated ex per i men tally. The ef fect of the cell tem per a ture, meth a nol con cen tra tion, and ox y gen flow rate on cell per for mance was stud ied. The study re veals that cur rent den sity is not mo not onous func tion of tem per a ture, but has an op ti mum op er at ing con di tion for each cell volt age. The ex per i ments also in di cate that the cell per for mance in creases with an in creased of ox y gen flow rate up to a cer tain value and then fur ther in crease has no sig nif i cant ef fect. Fur ther more, for meth a nol con cen tra tion greater than 1.5 M, a re duc tion of cell volt age was in di cated which is due to an in crease of meth a nol cross over.

Research paper thumbnail of 3D printing of PEEK-based medical devices

Transactions on Additive Manufacturing Meets Medicine, Sep 12, 2019

Polyether-ether-ketone (PEEK) is an excellent thermoplastic alternative to metallic biomaterials ... more Polyether-ether-ketone (PEEK) is an excellent thermoplastic alternative to metallic biomaterials which is used for loadbearing applications due to its high strength and stiffness, and biocompatibility with no cytotoxic effects. However, a potential clinical concern is that PEEK alone is not bioactive enough, and thus has limited fixation to bone. To overcome this problem, bioactive materials and/or porosity are incorporated into PEEK medical devices. The latest developments in these two strategies are presented in this paper. Bioactive PEEK/hydroxyapatite (HA) prepared by integration of 3D printing and compression molding is presented in this paper. In addition, nozzle and build plate temperatures for 3D printing of porous PEEK were optimized using genetic algorithm (GA) to achieve the highest mechanical strength for load bearing applications such as spinal fusion cages.

Research paper thumbnail of Determination of the effective parameters on the fuel cell efficiency, based on sealing behavior of the system

International Journal of Hydrogen Energy, Oct 1, 2016

Distribution and its magnitude pressure on gas diffusion layer (GDL) have direct influence on eff... more Distribution and its magnitude pressure on gas diffusion layer (GDL) have direct influence on efficiency of the fuel cell. There are various parameters which affect the pressure. The aim of this investigation is to provide predetermined uniform distribution over GDL by choosing appropriate parameters (e. g. clamping force, thickness of end plate and sealant groove depth). First of all, using an experimental sealing test, the minimum compression stress over washer for no leakage condition was achieved to be 2 MPa. Sealing of the fuel cell stack was considered as a criterion for analyzing proper pressure distribution. In other words, we sought for an operational condition in which the applied stress over the washer and the magnitude of uniform pressure over GDL reach to the predetermined value. Furthermore, the influence of effective parameters such as clamping force, sealant groove depth, and thickness of end plate on the uniform pressure distribution over GDL were examined and discussed. Finally, the optimum values were reported based on the minimum clamping force, complete sealing condition, and uniform pressure distribution over the GDL.

Research paper thumbnail of Joining of 1100 Al Alloy to AISI 1045 Carbon Steel by Friction Stir Welding

Applied Mechanics and Materials, 2012

Joining of dissimilar materials like Al alloy to carbon steel is attractive for industrial applic... more Joining of dissimilar materials like Al alloy to carbon steel is attractive for industrial applications such as automotive industry. In this research, Friction Stir Welding (FSW) has been used to joint between dissimilar materials like 1100 Al alloys to AISI 1045 carbon steel. In this paper, the effect of rotational speed, feedrate and offset of tool are investigated on mechanical and metallurgical properties of the welding. The joints were evaluated by mechanical testing and metallurgical analysis. Metallurgical properties carried out by optical microscopy and Scanning Electron Microscopy (SEM) and mechanical properties conducted by the joint strength. Finally, optimum value of tool rotational speed and feedrate were obtained 710 rpm and 28 mm/min respectively and the best offset value of the tool obtained 1.5 mm in the Al alloy. Tensile strength properties of Al1100/1045 carbon steel joints were found to be approximately 20% lower than that of the Al 1100-H14 alloy base metal

Research paper thumbnail of Open Cell Metal Foam as Extended Coolant Surface – Fuel Cell Application

Fuel Cells, Apr 1, 2020

Consisting of randomly oriented cells with nearly uniform shapes, open cell metal foams are consi... more Consisting of randomly oriented cells with nearly uniform shapes, open cell metal foams are considered to be reliable in heat transfer applications. Numerical tools and experimental tests were applied to assess the thermo-hydraulic behavior of aluminum metal foam sheet adjacent to the heated wall in role of polymer electrolyte membrane (PEM) fuel cell end plate. Convective cooling media passing through the metal foam sheet carries heat being conducted through the plate and metal foam matrix. The plate with constant heat flux is considered to be the heat source in both numerical and experimental approaches. Numerical model was applied for simulation of the metal foam sheet through porous media assumptions. The experimental set up was also assembled to verify the theory. The comparison between the numerical results and experimental data revealed acceptable agreement. The porosity percentage, heat flux, the metal foam sheet height and the coolant media velocity were the investigated variables. Finally, the result showed that the outlet temperature would increase straightly with the porosity percentage decrement. Whilst, on the other hand the pressure drop decreased by porosity enhancement.

Research paper thumbnail of Effect of Tool Rotation Speed and Feed Rate on Friction Stir Welding of 1100 Aluminum Alloy to Carbon Steel

Advanced Materials Research, 2012

Research paper thumbnail of Integration of reverse engineering and rapid technologies for rapid investment casting of gas turbine blades

Virtual and Physical Prototyping, Dec 1, 2011

The aim of this research work is to offer a unique procedure of integrated Reverse Engineering (R... more The aim of this research work is to offer a unique procedure of integrated Reverse Engineering (RE) and Additive Manufacturing (AM) technologies through implementation of a comprehensive experimental study to present an extensive comparison between ...

Research paper thumbnail of Implementation of an automated operation planning and optimum operation sequencing and tool selection algorithms

Computers in Industry, Aug 1, 2004

Low volume and high product mix characterize a job shop manufacturing. The CAM software in genera... more Low volume and high product mix characterize a job shop manufacturing. The CAM software in generating NC programs needs to reduce dependence on human judgment in operation planning in order to be used in low repetitive and high product mix production environments. In this research, a procedure for extracting machining methods for automated operation planning is proposed. Furthermore, an optimum

Research paper thumbnail of Experimental and numerical investigation on passive and active μDMFC

International Journal of Hydrogen Energy, Sep 1, 2010

In this paper, design and fabrication of a micro direct methanol fuel cell based on stainless ste... more In this paper, design and fabrication of a micro direct methanol fuel cell based on stainless steel in two kind of active and passive with cross strip and parallel flow field are presented. Dropping pressure, velocity and heat transfer of the cell is simulated by a 3D modeling in fluent software. An optimum operating condition of the cell is obtained

Research paper thumbnail of 3D printing of glass fiber reinforced acrylonitrile butadiene styrene and investigation of tensile, flexural, warpage and roughness properties

Polymer Composites, Aug 4, 2022

Three‐dimensional (3D) printing or additive manufacturing (AM) enables to fabricate, complex part... more Three‐dimensional (3D) printing or additive manufacturing (AM) enables to fabricate, complex parts in low quantities without expensive molds or tools in short time. While several 3D printing methods are available, printing with the method of fused deposition modeling (FDM) is particularly widespread because of the simplicity and potential applicability. The applications of FDM to obtain strong components used in aerospace and automotive industries are widely being explored. This study investigates mechanical properties of 3D printed parts with composite filaments made by acrylonitrile butadiene styrene (ABS)/short glass fibers (SGFs). At first, composite filaments with varying GF contents 5, 10, and 15 wt% were manufactured. In addition, maleic anhydride grafted ABS (ABS‐g‐MA) as coupling agent, nozzle temperature and raster angle orientation were considered as other parameters. Results showed that with 15 wt% of GF, means of tensile and flexural strengths were increased 33% and 36%, respectively. Meanwhile, tensile and flexural moduli were improved 57% and 62%. Among the different raster angle, 0° had the best mechanical properties. Maximum ultimate tensile strength was obtained 61 MPa. Warpage and surface roughness were measured in this study. Generally, nozzle temperature and coupling agent did not have any significant effects on all the results in this study.

Research paper thumbnail of Effects of temperature and reactant on performance of PEM fuel cell

Research paper thumbnail of Effect of Polymer Concentration on the Structure and Performance of Polysulfone Flat Membrane for CO2 Absorption in Membrane Contactor

In this study, polysulfone (PSF) flat membrane prepared via non-solvent phase inversion method wa... more In this study, polysulfone (PSF) flat membrane prepared via non-solvent phase inversion method was employed in gas-liquid membrane contactor module to absorb CO 2. Two polymer concentrations of 16 wt% and 18 wt% were used in the dope solution of fabricated membranes. The membranes were characterized in terms of morphological structure and contact angle. Scanning electron microscopy (SEM) analysis demonstrated that PSF membrane with polymer concentration of 16 wt% in the dope solution has a porous layer with a combination of finger-like, sponge-like and macrovoid structures, but the other membrane has a sponge-like structure. Also, characterization results through atomic force microscopy (AFM) and contact angle measurement demonstrated that the porosity, surface roughness and hydrophobicity of the PSF membranes decreased with an increase in polymer concentration. Evaluation of mass transfer resistance displayed that the resistance of the PSF membrane with polymer concentration of 18wt% in the dope solution is higher than that of the other membrane. In addition, decreasing the polymer concentration significantly improved CO 2 absorption flux. At the absorbent flow rate of 9.7 ml/min, the CO 2 absorption flux of PSF membrane with 16 wt% polymer concentration was 2.17 times higher than the absorption flux of the PSF with 18 wt% polymer concentration.

Research paper thumbnail of Automated NC Program Generation for Grinding Wheel Dressing of Special Profile Grinding Machine

Research paper thumbnail of Effect of Friction Stir Welding Parameters on Microstructure and Mechanical Properties of Dissimilar Joint Al Alloy to Stainless Steel

Aerospace Mechanics Journal, Apr 15, 2015

Friction Stir Welding (FSW) is a solid-state welding process used for welding similar and dissimi... more Friction Stir Welding (FSW) is a solid-state welding process used for welding similar and dissimilar materials. FSW is especially suitable to join sheet Al alloys, and this technique allows different material couples to be welded continuously. In this study, 1050 Al alloys and commercially pure Cu were produced at three different tool rotation speeds (630, 1330, 2440 rpm) and three different tool traverse speeds (20, 30, 50 mm/min) with four different tool position (0, 1, 1.5, 2 mm) by friction stir welding. The influence of the welding parameters on the microstructure and mechanical properties of the joints was investigated. Tensile and bending tests and microhardness measurements were used to determine the mechanical properties. The microstructures of the weld zone were investigated by optical microscope and scanning electron microscope (SEM) and were analyzed in an energy dispersed spectrometer (EDS). Intermetallic phases were detected based on the X-ray diffraction (XRD) analysis results that evaluated the formation of phases in the weld zone. When the welding performance of the friction stir welded butt joints was evaluated, the maximum value obtained was 89.55% with a 1330 rpm tool rotational speed, 20 mm/min traverse speed and a 1 mm tool position configuration. The higher tensile strength is attributed to the dispersion strengthening of the fine Cu particles distributed over the Al material in the stir zone region.

Research paper thumbnail of Design Criteria of a DMFC Stack with Low Scaling Effects

Applied Mechanics and Materials, 2012

In this paper, recent advances in design and fabrication of a direct methanol fuel cell (DMFC) st... more In this paper, recent advances in design and fabrication of a direct methanol fuel cell (DMFC) stack are presented. DMFC fuel cells are viewed as one of the most environmentally friendly energy conversion system due to high theoretical electrical efficiency for portable application. These advantages are mainly depends on overall system design and especially on stack operating performance. In order to increase the performance of the overall system, design criteria of a DMFC stack has been considered. A DMFC stack with optimum flow field, flow direction, uniform pressure drop and flow distribution has been constructed. Scale effects respect to the number of cells are tested on single cell, short stack and stack by a homemade test bench. The results are shown the scale effect respect to the number of cells is ignorable.

Research paper thumbnail of Error Analysis in Multistage Machining Process Using Kinematic Analysis of Workpiece Fixturing

Applied Mechanics and Materials, 2012

Fixtures are used to locate and hold workpieces with locators and clamps. As well as having a loc... more Fixtures are used to locate and hold workpieces with locators and clamps. As well as having a locating function, fixtures must also ensure that the dimensional quality of the manufactured workpiece can be achieved. Inaccuracies in fixture’s location scheme result in a deviation of the workpiece from its nominal specified geometry. A “multistage” machining process refers to a part that is machined through different setups. At multistage machining, the errors of pervious stages are transferred to next stages. In this paper, an analytic model is developed to integrate the errors in each stage and accumulated error of pervious stages. This model has great potential to be applied toward fault diagnosis and process design evaluation for the multistage process. A mathematical model is developed by the kinematic analysis of the fixture using Jacobian matrix and homogeneous transformation matrix (HTM). The effectiveness of the resultant deviation model is verified by example.

Research paper thumbnail of A Numerical Simulation of Vanadium Redox Flow Batteries

International journal of engineering. Transactions A: basics, 2019

Research paper thumbnail of Application of Particle Swarm Optimization in Computer Aided Setup Planning

INTERNATIONAL CONFERENCE ON ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES (AMPT2010), 2011

Research paper thumbnail of Computer Aided Setup Planning Using Tolerance Analysis for Prismatic Components

INTERNATIONAL CONFERENCE ON ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES (AMPT2010), 2011

Research paper thumbnail of Fixture design concept for high-product-mix and extremely low-repetitive machining center work

Research paper thumbnail of Effects of operating parameters on performance of a single direct methanol fuel cell

Thermal Science, 2010

In this study the ef fect of var i ous op er at ing con di tions on 10 cm ×10 cm ac tive area of ... more In this study the ef fect of var i ous op er at ing con di tions on 10 cm ×10 cm ac tive area of in-house fab ri cated di rect meth a nol fuel cell was in ves ti gated ex per i men tally. The ef fect of the cell tem per a ture, meth a nol con cen tra tion, and ox y gen flow rate on cell per for mance was stud ied. The study re veals that cur rent den sity is not mo not onous func tion of tem per a ture, but has an op ti mum op er at ing con di tion for each cell volt age. The ex per i ments also in di cate that the cell per for mance in creases with an in creased of ox y gen flow rate up to a cer tain value and then fur ther in crease has no sig nif i cant ef fect. Fur ther more, for meth a nol con cen tra tion greater than 1.5 M, a re duc tion of cell volt age was in di cated which is due to an in crease of meth a nol cross over.

Research paper thumbnail of 3D printing of PEEK-based medical devices

Transactions on Additive Manufacturing Meets Medicine, Sep 12, 2019

Polyether-ether-ketone (PEEK) is an excellent thermoplastic alternative to metallic biomaterials ... more Polyether-ether-ketone (PEEK) is an excellent thermoplastic alternative to metallic biomaterials which is used for loadbearing applications due to its high strength and stiffness, and biocompatibility with no cytotoxic effects. However, a potential clinical concern is that PEEK alone is not bioactive enough, and thus has limited fixation to bone. To overcome this problem, bioactive materials and/or porosity are incorporated into PEEK medical devices. The latest developments in these two strategies are presented in this paper. Bioactive PEEK/hydroxyapatite (HA) prepared by integration of 3D printing and compression molding is presented in this paper. In addition, nozzle and build plate temperatures for 3D printing of porous PEEK were optimized using genetic algorithm (GA) to achieve the highest mechanical strength for load bearing applications such as spinal fusion cages.

Research paper thumbnail of Determination of the effective parameters on the fuel cell efficiency, based on sealing behavior of the system

International Journal of Hydrogen Energy, Oct 1, 2016

Distribution and its magnitude pressure on gas diffusion layer (GDL) have direct influence on eff... more Distribution and its magnitude pressure on gas diffusion layer (GDL) have direct influence on efficiency of the fuel cell. There are various parameters which affect the pressure. The aim of this investigation is to provide predetermined uniform distribution over GDL by choosing appropriate parameters (e. g. clamping force, thickness of end plate and sealant groove depth). First of all, using an experimental sealing test, the minimum compression stress over washer for no leakage condition was achieved to be 2 MPa. Sealing of the fuel cell stack was considered as a criterion for analyzing proper pressure distribution. In other words, we sought for an operational condition in which the applied stress over the washer and the magnitude of uniform pressure over GDL reach to the predetermined value. Furthermore, the influence of effective parameters such as clamping force, sealant groove depth, and thickness of end plate on the uniform pressure distribution over GDL were examined and discussed. Finally, the optimum values were reported based on the minimum clamping force, complete sealing condition, and uniform pressure distribution over the GDL.

Research paper thumbnail of Joining of 1100 Al Alloy to AISI 1045 Carbon Steel by Friction Stir Welding

Applied Mechanics and Materials, 2012

Joining of dissimilar materials like Al alloy to carbon steel is attractive for industrial applic... more Joining of dissimilar materials like Al alloy to carbon steel is attractive for industrial applications such as automotive industry. In this research, Friction Stir Welding (FSW) has been used to joint between dissimilar materials like 1100 Al alloys to AISI 1045 carbon steel. In this paper, the effect of rotational speed, feedrate and offset of tool are investigated on mechanical and metallurgical properties of the welding. The joints were evaluated by mechanical testing and metallurgical analysis. Metallurgical properties carried out by optical microscopy and Scanning Electron Microscopy (SEM) and mechanical properties conducted by the joint strength. Finally, optimum value of tool rotational speed and feedrate were obtained 710 rpm and 28 mm/min respectively and the best offset value of the tool obtained 1.5 mm in the Al alloy. Tensile strength properties of Al1100/1045 carbon steel joints were found to be approximately 20% lower than that of the Al 1100-H14 alloy base metal

Research paper thumbnail of Open Cell Metal Foam as Extended Coolant Surface – Fuel Cell Application

Fuel Cells, Apr 1, 2020

Consisting of randomly oriented cells with nearly uniform shapes, open cell metal foams are consi... more Consisting of randomly oriented cells with nearly uniform shapes, open cell metal foams are considered to be reliable in heat transfer applications. Numerical tools and experimental tests were applied to assess the thermo-hydraulic behavior of aluminum metal foam sheet adjacent to the heated wall in role of polymer electrolyte membrane (PEM) fuel cell end plate. Convective cooling media passing through the metal foam sheet carries heat being conducted through the plate and metal foam matrix. The plate with constant heat flux is considered to be the heat source in both numerical and experimental approaches. Numerical model was applied for simulation of the metal foam sheet through porous media assumptions. The experimental set up was also assembled to verify the theory. The comparison between the numerical results and experimental data revealed acceptable agreement. The porosity percentage, heat flux, the metal foam sheet height and the coolant media velocity were the investigated variables. Finally, the result showed that the outlet temperature would increase straightly with the porosity percentage decrement. Whilst, on the other hand the pressure drop decreased by porosity enhancement.

Research paper thumbnail of Effect of Tool Rotation Speed and Feed Rate on Friction Stir Welding of 1100 Aluminum Alloy to Carbon Steel

Advanced Materials Research, 2012

Research paper thumbnail of Integration of reverse engineering and rapid technologies for rapid investment casting of gas turbine blades

Virtual and Physical Prototyping, Dec 1, 2011

The aim of this research work is to offer a unique procedure of integrated Reverse Engineering (R... more The aim of this research work is to offer a unique procedure of integrated Reverse Engineering (RE) and Additive Manufacturing (AM) technologies through implementation of a comprehensive experimental study to present an extensive comparison between ...

Research paper thumbnail of Implementation of an automated operation planning and optimum operation sequencing and tool selection algorithms

Computers in Industry, Aug 1, 2004

Low volume and high product mix characterize a job shop manufacturing. The CAM software in genera... more Low volume and high product mix characterize a job shop manufacturing. The CAM software in generating NC programs needs to reduce dependence on human judgment in operation planning in order to be used in low repetitive and high product mix production environments. In this research, a procedure for extracting machining methods for automated operation planning is proposed. Furthermore, an optimum

Research paper thumbnail of Experimental and numerical investigation on passive and active μDMFC

International Journal of Hydrogen Energy, Sep 1, 2010

In this paper, design and fabrication of a micro direct methanol fuel cell based on stainless ste... more In this paper, design and fabrication of a micro direct methanol fuel cell based on stainless steel in two kind of active and passive with cross strip and parallel flow field are presented. Dropping pressure, velocity and heat transfer of the cell is simulated by a 3D modeling in fluent software. An optimum operating condition of the cell is obtained

Research paper thumbnail of 3D printing of glass fiber reinforced acrylonitrile butadiene styrene and investigation of tensile, flexural, warpage and roughness properties

Polymer Composites, Aug 4, 2022

Three‐dimensional (3D) printing or additive manufacturing (AM) enables to fabricate, complex part... more Three‐dimensional (3D) printing or additive manufacturing (AM) enables to fabricate, complex parts in low quantities without expensive molds or tools in short time. While several 3D printing methods are available, printing with the method of fused deposition modeling (FDM) is particularly widespread because of the simplicity and potential applicability. The applications of FDM to obtain strong components used in aerospace and automotive industries are widely being explored. This study investigates mechanical properties of 3D printed parts with composite filaments made by acrylonitrile butadiene styrene (ABS)/short glass fibers (SGFs). At first, composite filaments with varying GF contents 5, 10, and 15 wt% were manufactured. In addition, maleic anhydride grafted ABS (ABS‐g‐MA) as coupling agent, nozzle temperature and raster angle orientation were considered as other parameters. Results showed that with 15 wt% of GF, means of tensile and flexural strengths were increased 33% and 36%, respectively. Meanwhile, tensile and flexural moduli were improved 57% and 62%. Among the different raster angle, 0° had the best mechanical properties. Maximum ultimate tensile strength was obtained 61 MPa. Warpage and surface roughness were measured in this study. Generally, nozzle temperature and coupling agent did not have any significant effects on all the results in this study.

Research paper thumbnail of Effects of temperature and reactant on performance of PEM fuel cell

Research paper thumbnail of Effect of Polymer Concentration on the Structure and Performance of Polysulfone Flat Membrane for CO2 Absorption in Membrane Contactor

In this study, polysulfone (PSF) flat membrane prepared via non-solvent phase inversion method wa... more In this study, polysulfone (PSF) flat membrane prepared via non-solvent phase inversion method was employed in gas-liquid membrane contactor module to absorb CO 2. Two polymer concentrations of 16 wt% and 18 wt% were used in the dope solution of fabricated membranes. The membranes were characterized in terms of morphological structure and contact angle. Scanning electron microscopy (SEM) analysis demonstrated that PSF membrane with polymer concentration of 16 wt% in the dope solution has a porous layer with a combination of finger-like, sponge-like and macrovoid structures, but the other membrane has a sponge-like structure. Also, characterization results through atomic force microscopy (AFM) and contact angle measurement demonstrated that the porosity, surface roughness and hydrophobicity of the PSF membranes decreased with an increase in polymer concentration. Evaluation of mass transfer resistance displayed that the resistance of the PSF membrane with polymer concentration of 18wt% in the dope solution is higher than that of the other membrane. In addition, decreasing the polymer concentration significantly improved CO 2 absorption flux. At the absorbent flow rate of 9.7 ml/min, the CO 2 absorption flux of PSF membrane with 16 wt% polymer concentration was 2.17 times higher than the absorption flux of the PSF with 18 wt% polymer concentration.

Research paper thumbnail of Automated NC Program Generation for Grinding Wheel Dressing of Special Profile Grinding Machine

Research paper thumbnail of Effect of Friction Stir Welding Parameters on Microstructure and Mechanical Properties of Dissimilar Joint Al Alloy to Stainless Steel

Aerospace Mechanics Journal, Apr 15, 2015

Friction Stir Welding (FSW) is a solid-state welding process used for welding similar and dissimi... more Friction Stir Welding (FSW) is a solid-state welding process used for welding similar and dissimilar materials. FSW is especially suitable to join sheet Al alloys, and this technique allows different material couples to be welded continuously. In this study, 1050 Al alloys and commercially pure Cu were produced at three different tool rotation speeds (630, 1330, 2440 rpm) and three different tool traverse speeds (20, 30, 50 mm/min) with four different tool position (0, 1, 1.5, 2 mm) by friction stir welding. The influence of the welding parameters on the microstructure and mechanical properties of the joints was investigated. Tensile and bending tests and microhardness measurements were used to determine the mechanical properties. The microstructures of the weld zone were investigated by optical microscope and scanning electron microscope (SEM) and were analyzed in an energy dispersed spectrometer (EDS). Intermetallic phases were detected based on the X-ray diffraction (XRD) analysis results that evaluated the formation of phases in the weld zone. When the welding performance of the friction stir welded butt joints was evaluated, the maximum value obtained was 89.55% with a 1330 rpm tool rotational speed, 20 mm/min traverse speed and a 1 mm tool position configuration. The higher tensile strength is attributed to the dispersion strengthening of the fine Cu particles distributed over the Al material in the stir zone region.

Research paper thumbnail of Design Criteria of a DMFC Stack with Low Scaling Effects

Applied Mechanics and Materials, 2012

In this paper, recent advances in design and fabrication of a direct methanol fuel cell (DMFC) st... more In this paper, recent advances in design and fabrication of a direct methanol fuel cell (DMFC) stack are presented. DMFC fuel cells are viewed as one of the most environmentally friendly energy conversion system due to high theoretical electrical efficiency for portable application. These advantages are mainly depends on overall system design and especially on stack operating performance. In order to increase the performance of the overall system, design criteria of a DMFC stack has been considered. A DMFC stack with optimum flow field, flow direction, uniform pressure drop and flow distribution has been constructed. Scale effects respect to the number of cells are tested on single cell, short stack and stack by a homemade test bench. The results are shown the scale effect respect to the number of cells is ignorable.

Research paper thumbnail of Error Analysis in Multistage Machining Process Using Kinematic Analysis of Workpiece Fixturing

Applied Mechanics and Materials, 2012

Fixtures are used to locate and hold workpieces with locators and clamps. As well as having a loc... more Fixtures are used to locate and hold workpieces with locators and clamps. As well as having a locating function, fixtures must also ensure that the dimensional quality of the manufactured workpiece can be achieved. Inaccuracies in fixture’s location scheme result in a deviation of the workpiece from its nominal specified geometry. A “multistage” machining process refers to a part that is machined through different setups. At multistage machining, the errors of pervious stages are transferred to next stages. In this paper, an analytic model is developed to integrate the errors in each stage and accumulated error of pervious stages. This model has great potential to be applied toward fault diagnosis and process design evaluation for the multistage process. A mathematical model is developed by the kinematic analysis of the fixture using Jacobian matrix and homogeneous transformation matrix (HTM). The effectiveness of the resultant deviation model is verified by example.