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The Fracture Behavior Of An Al–Mg–Si Alloy During Cyclic Fatigue, Diya Azzam, Craig Menzemer, Tirumalai Srivatsan
The Fracture Behavior Of An Al–Mg–Si Alloy During Cyclic Fatigue, Diya Azzam, Craig Menzemer, Tirumalai Srivatsan
Craig Menzemer
In this paper, is presented and discussed the cyclic fracture behavior of the Al–Mg–Si alloy 6063 that is a candidate used in luminaire light poles. The light poles were subject to fatigue deformation. Test sections were taken from the failed region of the light pole and carefully examined in a scanning electron microscope with the objective of rationalizing the macroscopic fracture mode and intrinsic micromechanisms governing fracture under cyclic loading. The fatigue fracture surface of the alloy revealed distinct regions of early microscopic crack growth, stable crack growth and unstable crack growth and overload. An array of fine striations was …
A Study To Evaluate And Understand The Response Of Aluminum Alloy 2026 Subjected To Tensile Deformation, Daniel Lam, Craig Menzemer, Tirumalai Srivatsan
A Study To Evaluate And Understand The Response Of Aluminum Alloy 2026 Subjected To Tensile Deformation, Daniel Lam, Craig Menzemer, Tirumalai Srivatsan
Craig Menzemer
The strain concentration factors were determined for aluminum alloy 2026 in the T3511 temper using multi-hole structural coupon specimens. Samples of the alloy were evaluated for both the 6.25 mm (0.25 in.) thick and 10 mm (0.4 in.) thick specimens and having widths of 50 mm (2 in.) and 100 mm (4 in.), respectively. For the case of the specimens that were 50 mm in width the mechanical tests were conducted for both the open hole and filled hole conditions and the corresponding strain concentration value was determined. Threaded fasteners having collars were used for the case of the filled …
Mechanisms Governing Fatigue, Damage, And Fracture Of Commercially Pure Titanium For Viable Aerospace Applications, Udaykar Bathini, Tirumalai Srivatsan, Anil Patnaik, Craig Menzemer
Mechanisms Governing Fatigue, Damage, And Fracture Of Commercially Pure Titanium For Viable Aerospace Applications, Udaykar Bathini, Tirumalai Srivatsan, Anil Patnaik, Craig Menzemer
Craig Menzemer
In this paper, the cyclic stress amplitude controlled high-cycle fatigue properties and final fracture behavior of commercially pure titanium (Grade 2) are presented and discussed. The material characterization was developed and put forth for selection and use in a spectrum of applications spanning the industries of aerospace, defense, chemical, marine, and commercial products. Test specimens were prepared from the as-received plate stock of the material with the stress axis both parallel (longitudinal) and perpendicular (transverse) to the rolling direction of the plate. The test specimens were cyclically deformed at a constant load ratio of 0.1, at different values of maximum …
Investigating And Understanding The Fatigue Response And Failure Of Built-Up Welded Beams Of A Titanium Alloy, Anil Patnaik, Narendra Poondla, Udaykar Bathini, Tirumalai Srivatsan, T. Quick
Investigating And Understanding The Fatigue Response And Failure Of Built-Up Welded Beams Of A Titanium Alloy, Anil Patnaik, Narendra Poondla, Udaykar Bathini, Tirumalai Srivatsan, T. Quick
Anil Patnaik
No abstract provided.
A Study Of The Microstructure And Hardness Of Two Titanium Alloys: Commercially Pure And Ti–6al–4v, Narendra Poondla, Tirumalai Srivatsan, Anil Patnaik, M. Petraroli
A Study Of The Microstructure And Hardness Of Two Titanium Alloys: Commercially Pure And Ti–6al–4v, Narendra Poondla, Tirumalai Srivatsan, Anil Patnaik, M. Petraroli
Anil Patnaik
In this paper, the microstructure and hardness of two titanium alloys was determined and the results are presented and briefly discussed. Samples of the alloy for microstructural examination were prepared from the as-provided stock using standard metallographic procedures and then examined in a low magnification light optical microscope. Both microhardness and macrohardness measurements were made across the polished surfaces of the two titanium materials. Both the microhardness and macrohardness of the Ti–6Al–4V alloy was noticeably higher than the commercially pure counterpart. The intrinsic influence of alloy composition and secondary processing, i.e., annealing, on microstructural development is presented and hardness of …
Mechanisms Governing Fatigue, Damage, And Fracture Of Commercially Pure Titanium For Viable Aerospace Applications, Udaykar Bathini, Tirumalai Srivatsan, Anil Patnaik, Craig Menzemer
Mechanisms Governing Fatigue, Damage, And Fracture Of Commercially Pure Titanium For Viable Aerospace Applications, Udaykar Bathini, Tirumalai Srivatsan, Anil Patnaik, Craig Menzemer
Anil Patnaik
In this paper, the cyclic stress amplitude controlled high-cycle fatigue properties and final fracture behavior of commercially pure titanium (Grade 2) are presented and discussed. The material characterization was developed and put forth for selection and use in a spectrum of applications spanning the industries of aerospace, defense, chemical, marine, and commercial products. Test specimens were prepared from the as-received plate stock of the material with the stress axis both parallel (longitudinal) and perpendicular (transverse) to the rolling direction of the plate. The test specimens were cyclically deformed at a constant load ratio of 0.1, at different values of maximum …
A Study Of Cyclic Fatigue, Damage Initiation, Damage Propagation, And Fracture Of Welded Titanium Alloy Plate, Tirumalai Srivatsan, Udaykar Bathini, Anil Patnaik, T. Quick
A Study Of Cyclic Fatigue, Damage Initiation, Damage Propagation, And Fracture Of Welded Titanium Alloy Plate, Tirumalai Srivatsan, Udaykar Bathini, Anil Patnaik, T. Quick
Anil Patnaik
In this paper, the influence of test specimen orientation and microstructure on cyclic stress-amplitude controlled fatigue response, damage initiation, damage propagation and fracture behavior of samples taken from a welded plate of titanium alloy is presented and discussed. Test specimens from the chosen alloy were prepared from an as-welded plate of the material with the stress axis both parallel (longitudinal) and perpendicular (transverse) to the deformed (rolling) direction of the plate. The test specimens were cyclically deformed at different values of maximum stress at a constant load ratio of 0.1, and the resultant cycles-to-failure was recorded. The fracture surfaces of …
The Tribological And Electrochemical Behavior Of Hvof-Sprayed Cr3c2-Nicr Ceramic Coating On Carbon Steel
Faculty of Engineering University of Malaya
High Velocity Oxygen Fuel (HVOF) is an excellent approach to prepare a good, wear-resistant lamella of Chromium Carbide-Nickel Chrome (Cr3C2-NiCr) on carbon steel for high temperature application. This research investigates the effect of a thin, deposited layer of Cr3C2-NiCr on carbon steel in terms of wear and corrosion properties. The microstructure of the HVOF-sprayed Cr3C2-NiCr coating was characterized at each step by scanning electron microscopy. Wear testing was performed with a pin-on-disk tester. Wear weight loss was examined by applying different loads over a 9048.96 m sliding distance. Experimental results show that the wear resistance of the coated sample reduced …
The Quasi-Static And Cyclic Fatigue Fracture Behavior Of An Emerging Titanium Alloy, Kannan Manigandan, Tirumalai Srivatsan, Gregory Morscher
The Quasi-Static And Cyclic Fatigue Fracture Behavior Of An Emerging Titanium Alloy, Kannan Manigandan, Tirumalai Srivatsan, Gregory Morscher
Dr. Gregory N. Morscher
Sustained research and development efforts culminating in the emergence of new and improved titanium alloys have provided both the impetus and interest for studying their mechanical behavior under the extrinsic influence of loading spanning both static and dynamic. In this article, the quasi-static and cyclic fatigue fracture behavior of a titanium alloy (Ti-Al-V-Fe-O2) is highlighted. Test specimens of this titanium alloy were deformed both in quasi-static tension and cyclic stress amplitude–controlled fatigue. The quasi-static mechanical properties, cyclic fatigue response and microscopic mechanisms contributing to deformation and eventual fracture are highlighted in light of the competing and mutually interactive influences of …
An Investigation Of Nanoparticles Addition On Solidification Kinetics And Microstructure Development Of Tin–Lead Solder, D. Lin, S. Liu, T. Guo, Guo-Xiang Wang, T. Srivatsan, M. Petraroli
An Investigation Of Nanoparticles Addition On Solidification Kinetics And Microstructure Development Of Tin–Lead Solder, D. Lin, S. Liu, T. Guo, Guo-Xiang Wang, T. Srivatsan, M. Petraroli
Dr. Guo-Xiang Wang
High strength solders can be engineered by adding trace amounts of nanopowders into solder paste. An experimental study was conducted for a better understanding of the solidification kinetics and microstructure development of such nano-composite tin–lead solders. The composite solder pastes were prepared by mechanically mixing nanopowders of either copper or TiO2 with tin–lead powders (tens of microns in size). Solidification experiments of the composite solders were performed in an aluminum crucible with temperature variation during cooling and solidification being measured. For the titanium dioxide (TiO2) nanopowders-reinforced composite solders, the test data reveals the occurrence of melt undercooling …
Synthesis And Characterization Of Nano-Composite Lead-Free Solder, D. Lin, C. Kuo, T. Srivatsan, M. Petraroli, Guo-Xiang Wang
Synthesis And Characterization Of Nano-Composite Lead-Free Solder, D. Lin, C. Kuo, T. Srivatsan, M. Petraroli, Guo-Xiang Wang
Dr. Guo-Xiang Wang
A series of experiments conducted on a lead-free eutectic solder (Sn-3.5%Ag) have shown that addition of trace amounts of nanometer-sized particles does have an influence on mechanical properties of materials. In this study, three different types of nanoparticles (copper, nickel and iron) were chosen as the reinforcing candidate. For each particulate reinforcement the reflow process was performed under identical cooling conditions. Addition of trace amounts of nano-particles alters the kinetics governing solidification of the composite solder paste while concurrently exerting an influence on microstructural development, particularly the formation and presence of second phases in the solidified end product. The nano-sized …
A Novel Combined Severe Plastic Deformation Method For Producing Thin-Walled Ultrafine Grained Cylindrical Tubes
Faculty of Engineering University of Malaya
A novel severe plastic deformation (SPD) process entitled combined parallel tubular channel angular pressing (PTCAP) and tube backward extrusion (TBE) is proposed for producing thin-walled ultrafine-grained (UFG) tubes. In this new combined SPD approach, the PTCAP and TBE processes are consequently applied to the tube material in which a severe plastic strain is applied to produce a UFG thin-walled tube. This technique was performed on an AZ31 magnesium tube, and a remarkable grain refinement was achieved. The results showed that this method could easily produce a high strength thin walled tube. The microhardness increased significantly to 70 HV after the …
Redox Stable Anodes For Solid Oxide Fuel Cells, Guoliang Xiao, Fanglin Chen
Redox Stable Anodes For Solid Oxide Fuel Cells, Guoliang Xiao, Fanglin Chen
Fanglin Chen
Solid oxide fuel cells (SOFCs) can convert chemical energy from the fuel directly to electrical energy with high efficiency and fuel flexibility. Ni-based cermets have been the most widely adopted anode for SOFCs. However, the conventional Ni-based anode has low tolerance to sulfur-contamination, is vulnerable to deactivation by carbon build-up (coking) from direct oxidation of hydrocarbon fuels, and suffers volume instability upon redox cycling. Among these limitations, the redox instability of the anode is particularly important and has been intensively studied since the SOFC anode may experience redox cycling during fuel cell operations even with the ideal pure hydrogen as …
Dissimilar Friction Stir Welding Between Polycarbonate And Aa 7075 Aluminum Alloy
Dissimilar Friction Stir Welding Between Polycarbonate And Aa 7075 Aluminum Alloy
Faculty of Engineering University of Malaya
In this paper, the effects of process parameters, such as the tool rotational and traverse speeds, on temperature evolution and the microstructural and mechanical properties of dissimilar friction stir welding between 3 mm thick AA 7075 aluminum alloy and polycarbonate (PC) plates were investigated. The tool rotational and traverse speeds were varied from 3 000 to 3 500 rpm and 50 to 150 mm min(-1), respectively. The joint fabricated at 3 250 rpm and 100 mm min(-1) yielded a highest tensile load of 586 N. Microstructural analysis of the stir zone revealed an interlock phenomenon, the transportation of AA 7075 …
Microstructure And Mechanical Properties Of Multipass Friction Stir Processed Aluminum Silicon Carbide Metal Matrix, Innovative Research Publications Irp India, V V Murali Krishna G, K.S Atyanarayana
Microstructure And Mechanical Properties Of Multipass Friction Stir Processed Aluminum Silicon Carbide Metal Matrix, Innovative Research Publications Irp India, V V Murali Krishna G, K.S Atyanarayana
Innovative Research Publications IRP India
In this study, SiC particles were incorporated by using Friction Stir Processing (FSP) into the 6351 aluminium alloy to form particulate composite materials. Sampels were subjected to constant rotational and traverse speeds of the FSP tool with and without SiC reinforcements. Microstructural observations were carried out by employing optical microscopy of the modifiedsurfaces. Mechanical properties were evaluated by tensile test on UTM. For the 100% overlapping, No.of passes caused grain modification in the processed zone. The tensile test results indicate an improvement of strength and Microhardness for Single Pass FSP samples and a reduction in the strength of FSP samples …
Fuzzy Logic Based Model For Predicting Surface Roughness Of Machined Al-Si-Cu-Fe Die Casting Alloy Using Different Additives-Turning
Faculty of Engineering University of Malaya
This paper presents a fuzzy logic artificial intelligence technique for predicting the machining performance of Al-Si-Cu-Fe die casting alloy treated with different additives including strontium, bismuth and antimony to improve surface roughness. The Pareto-ANOVA optimization method was used to obtain the optimum parameter conditions for the machining process. Experiments were carried out using oblique dry CNC turning. The machining parameters of cutting speed, feed rate and depth of cut were optimized according to surface roughness values. The results indicated that a cutting speed of 250 m/min, a feed rate of 0.05 mm/rev, and a depth of cut of 0.15 mm …
Investigating The Machinability Of Al-Si-Cu Cast Alloy Containing Bismuth And Antimony Using Coated Carbide Insert
Faculty of Engineering University of Malaya
Surface roughness and cutting force are two key measures that describe machined surface integrity and power requirement evaluation, respectively. This investigation presents the effect of melt treatment with addition of bismuth and antimony on machinability when turning Al-11% Si-2% Cu alloy. The experiments are carried out under oblique dry cutting conditions using a PVD TIN-coated insert at three cutting speeds of 70, 130 and 250 m/min, feed rates of 0.05, 0.1, 0.15 mm/rev, and 0.05 mm constant depth of cut. It was found that the Bi-containing workpiece possess the best surface roughness value and lowest cutting force due to formation …
Investigating The Electrical Discharge Machining (Edm) Parameter Effects On Al-Mg2si Metal Matrix Composite (Mmc) For High Material Removal Rate (Mrr) And Less Ewr-Rsm Approach
Faculty of Engineering University of Malaya
Al-Mg2Si composite is a new group of metalmatrix composites (MMCs). Electrical discharge machining (EDM) is a nonconventional machining process for machining electrically conductive materials regardless of hardness, strength and temperature resistance, complex shapes, fine surface finish/textures and accurate dimensions. A copper electrode and oil-based dielectric fluid mixed with aluminum powder were used. The polarity of electrode was positive. Response surface methodology (RSM) was used to analyze EDM of this composite material. This research illustrates the effect of input variables (voltage, current, pulse ON time, and duty factor) on material removal rate (MRR), electrode wear ratio (EWR), and microstructure changes. The …
Failure Analysis Of Superheater Tube Supports Of The Primary Reformer In A Fertilizer Factory
Failure Analysis Of Superheater Tube Supports Of The Primary Reformer In A Fertilizer Factory
A.S. Md Abdul Haseeb
Eutectic Sn-Bi alloy is gaining considerable attention in the electronic packaging industry because of its favorable properties such as low melting temperature, good wettability, and good mechanical properties. Miniaturization of electronic devices requires small solder bumps, a few tens of micrometers in diameter. Electrodeposition is a reliable technique for the deposition of small volume of solder. This work focuses on the formation of eutectic Sn-Bi solder by reflowing a metal stack containing sequentially electrodeposited Sn and Bi layers. The effects of layering sequence on the composition and microstructure of the resulting alloy is investigated. Irrespective of the layering sequence, a …
A Semi-Empirical Model To Predict The Acoustic Behaviour Of Fully And Partially Reticulated Polyurethane Foams Based On Microstructure Properties, Olivier Doutres Ph.D., Noureddine Atalla
A Semi-Empirical Model To Predict The Acoustic Behaviour Of Fully And Partially Reticulated Polyurethane Foams Based On Microstructure Properties, Olivier Doutres Ph.D., Noureddine Atalla
Olivier Doutres Ph.D.
This work investigates the links between the microstructure of polyurethane foams and their sound absorbing efficiency, and more specifically the effect of membranes closing the cells. In a previous work, the authors proposed a semi-empirical approach to link the foam microstructure properties, i.e. reticulation rate, strut length and thickness, with its non-acoustic parameters. The study was based on the complete characterization of 15 isotropic polyurethane foams with various cell sizes and reticulation rates (i.e. open pore content). This paper proposes a validation of this semi-empirical model using 3 new polyurethane foams, not used in the first characterization set. More importantly, …
Effects Of Addition Of Copper Particles Of Different Size To Sn-3.5ag Solder
Effects Of Addition Of Copper Particles Of Different Size To Sn-3.5ag Solder
A.S. Md Abdul Haseeb
No abstract provided.
Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications
Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications
A.S. Md Abdul Haseeb
For thermally stable LIGA materials for high temperature MEMS applications LIGA Ni-W layers and micro testing samples with different compositions (15 and 5 at% W) were electrodeposited. In order to investigate the thermal stability the Ni-W layers were annealed at different temperatures (300-700°C) and for different durations (1, 4, 16 h). Their microstructure and micro-hardness were than analysed after annealing and compared with those of as-deposited states. The observed microstructures show, in comparison to pure LIGA nickel, a small grain growth and a relatively stable structure up to 700°C. The micro-hardness values of the LIGA Ni-W layers are higher than …
Study Of The Wear Behaviour Of Al-4.5% Cu-3.4% Fe In Situ Composite: Effect Of Thermal And Mechanical Processing
A.S. Md Abdul Haseeb
Al-Cu-based MMCs reinforced by Al-Fe intermetallics are investigated for their wear behaviour. The composite (Al-4.5 mass% Cu-3.4 mass% Fe) was produced by solidification processing where the Al-Fe-based intermetallic formed in situ in a matrix of mainly Al-Cu alloy. The effects of thermal and mechanical processing, viz., as-cast condition, solution treatment, aging and hot rolling on the wear behaviour of the composites were examined. The composites were characterized by optical microscopy, SEM, microhardness measurements and X-ray diffraction. The wear behaviour of the composites was studied in a pin-on-disc type wear apparatus. The as-cast in situ composite exhibited the highest wear rate. …
Failure Analysis Of Superheater Tube Supports Of The Primary Reformer In A Fertilizer Factory
Failure Analysis Of Superheater Tube Supports Of The Primary Reformer In A Fertilizer Factory
A.S. Md Abdul Haseeb
A failure analysis of superheater tube supports of the primary reformer in a local fertilizer factor is presented. A number of tube supports failed at approximately half of their designed service life. Following the failure, the factory was visited, and relevant information and samples were collected. The samples were investigated in the laboratory by chemical analysis, macro- and microhardness measurements, macro-and micrometallographic examinations, and X-ray diffractometry. The analysis showed the supports were fabricated from HH-type heat-resisting alloy and that the failure mode was high-temperature creep. The microstructure of the alloy showed the presence of massive intergranular as well as intragranular …
Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data
A.S. Md Abdul Haseeb
This paper describes an investigation on the failure of a large leaded bronze bearing that supports a nine-ton roller of a plastic calendering machine. At the end of the normal service life of a good bearing, which lasted for seven years, a new bearing was installed. However the new one failed catastrophically within a few days, generating a huge amount of metallic wear debris and causing pitting on the surface of the cast iron roller. Following the failure, samples were collected from both good and failed bearings. The samples were analyzed chemically and their microstructures examined. Both samples were subjected …
Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data
A.S. Md Abdul Haseeb
This paper describes an investigation on the failure of a large leaded bronze bearing that supports a nine-ton roller of a plastic calendering machine. At the end of the normal service life of a good bearing, which lasted for seven years, a new bearing was installed. However the new one failed catastrophically within a few days, generating a huge amount of metallic wear debris and causing pitting on the surface of the cast iron roller. Following the failure, samples were collected from both good and failed bearings. The samples were analyzed chemically and their microstructures examined. Both samples were subjected …
Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data
A.S. Md Abdul Haseeb
This paper describes an investigation on the failure of a large leaded bronze bearing that supports a nine-ton roller of a plastic calendering machine. At the end of the normal service life of a good bearing, which lasted for seven years, a new bearing was installed. However the new one failed catastrophically within a few days, generating a huge amount of metallic wear debris and causing pitting on the surface of the cast iron roller. Following the failure, samples were collected from both good and failed bearings. The samples were analyzed chemically and their microstructures examined. Both samples were subjected …