Microstructural Evolution And Mechanical Properties Of Friction Stir Welded Ods Alloy Ma754,
2013
Missouri University of Science and Technology
Microstructural Evolution And Mechanical Properties Of Friction Stir Welded Ods Alloy Ma754, Jiye Wang, Wei Yuan, Rajiv S. Mishra, Indrajit Charit
Materials Science and Engineering Faculty Research & Creative Works
Microstructural evolution and mechanical properties of MA754, an yttrium oxide dispersion-strengthened nickel-based superalloy, were investigated after friction stir welding (FSW). A tool rotation rate of 1000 revolution per minute and a traverse speed of 50.8 mm per minute were employed using a cermet (WC-Co) tool. After FSW, fine equiaxed grain structure with a high dislocation density and a random texture was achieved. Agglomeration of yttrium oxide dispersoids was observed in FSW MA754. Room-temperature tensile properties of FSW MA754 were compared to those of as-received MA754 alloy, and the results indicated that particle strengthening contribution decreased as a result of dispersoid …
Additivity Of Strengthening Mechanisms In Ultrafine Grained Al-Mg-Sc Alloy,
2013
Missouri University of Science and Technology
Additivity Of Strengthening Mechanisms In Ultrafine Grained Al-Mg-Sc Alloy, N. Kumar, R. S. Mishra
Materials Science and Engineering Faculty Research & Creative Works
In the light of unique and anomalous properties of ultrafine grained (UFG) alloys, an effort was made to develop a predictive capability of the yield strength (YS) of UFG Al-Mg-Sc alloy. UFG microstructure was introduced using friction stir processing. Microstructural characterization of grain size, dislocations, and nano-sized Al3(Sc,Zr) particles was carried out using electron backscatter diffraction and transmission electron microscope. The contribution from Peierls-Nabarro stress, solid solution strengthening, precipitation strengthening, grain boundary strengthening, and dislocation strengthening were assessed using existing strengthening models. Additivity law to predict the YS of the alloy was chosen based on the microstructural state of the …
Probabilistic Simulation Of Solidification Microstructure Evolution During Laser-Based Metal Deposition,
2013
Missouri University of Science and Technology
Probabilistic Simulation Of Solidification Microstructure Evolution During Laser-Based Metal Deposition, Jingwei Zhang, Frank W. Liou, William Seufzer, Joseph William Newkirk, Zhiqiang Fan, Heng Liu, Todd E. Sparks
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A predictive model, based on a Cellular Automaton (CA) - Finite Element (FE) method, has been developed to simulate microstructure evolution during metal solidification for a laser based additive manufacturing process. The macroscopic FE calculation was designed to update the temperature field and simulate a high cooling rate. In the microscopic CA model, heterogeneous nucleation sites, preferential growth orientation and dendritic grain growth kinetics were simulated. The CA model was able to show the entrapment of neighboring cells and the relationship between undercooling and the grain growth rate. The model predicted the dendritic grain size, structure, and morphological evolution during …
The Effect Zeolite Addition In Natural Rubber Polypropylene Composite On Mechanical, Structure, And Thermal Characteristics,
2013
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan, Medan 20221, Indonesia
The Effect Zeolite Addition In Natural Rubber Polypropylene Composite On Mechanical, Structure, And Thermal Characteristics, Nurdin Bukit, Erna Frida
Makara Journal of Technology
This study was conducted to determine the effect of zeolite as filler on mechanical properties, and thermal structure blends of natural rubber and polypropylene (NR/PP). In this study, NR/PP/PP-g-MA blends was filled uncalcined zeolite and calcined zeolite at different weight percent of the 2, 4, and 6%. Samples were characterized to determine the tensile strength, fracture elongation and Young's modulus. Structure of the samples was investigated using XRD method and thermal characteristics were analyzed using DTA/TGA technique. The results obtained for tensile strength showed a significant influence with the addition zeolite of the NR/PP blends at 2% by weight of …
The Plasma Electrolysis Phenomenon In A Two-Compartment Reactor For Chlor-Alkali Production,
2013
Department of Chemical Engineering, Universitas Indonesia, Depok 16424, Indonesia
The Plasma Electrolysis Phenomenon In A Two-Compartment Reactor For Chlor-Alkali Production, Nelson Saksono, Fakhrian Abqari, Setijo Bismo
Makara Journal of Technology
Chlor-alkali is one of the most important processes in the chemical industry. It produces chlorine and caustic soda, which become the main feedstock of daily products. The aim of this study is to report the phenomenon of plasma electrolysis and how it can be used in chlor-alkali production for more efficient energy consumption. When the plasma is formed, the current fluctuates and gradually declines. Plasma electrolysis begins with the process of electrolysis itself. Due to Joule heating, gas bubbles are formed and a sheath is made on both electrodes, resulting in the plasma field. Plasma electrolysis can be identified by …
Determining The Air Gap Length Of An Axial Flux Wound Rotor Synchronous Generator,
2013
Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
Determining The Air Gap Length Of An Axial Flux Wound Rotor Synchronous Generator, Abdul Multi, Iwa Garniwa, Uno Bintang Sudibyo
Makara Journal of Technology
The air gap length of the designed axial flux wound rotor (AFWR) synchronous generator is determined properly according to the design parameters. One of the distinct advantages of an axial flux (AF) machine is its adjustable air gap. An AF generator’s performance might be controlled by adjusting its air gap. The designed generator has a smallscale capacity that has 1 kW, 380 V, and 50 Hz. The windings are laid into slots made from laminated core. The slots are carved in the face of the stator and rotors. The generator has a single-double-sided slotted wound stator sandwiched between twin rotors. …
Characteristics Of Vacuum Freeze Drying With Utilization Of Internal Cooling And Condenser Waste Heat For Sublimation,
2013
Department of Mechanical Engineering, Universitas Indonesia, Depok 16424, Indonesia
Characteristics Of Vacuum Freeze Drying With Utilization Of Internal Cooling And Condenser Waste Heat For Sublimation, Muhammad Idrus Alhamid, Nasruddin Yusuf, Indra Teuku Meurah Mahlia, Engkos Ahmad Kosasih, Muhamad Yulianto, Rio Ricardi
Makara Journal of Technology
Vacuum freeze drying is an excellent drying method, but it is very energy-intensive because a relatively long drying time is required. This research investigates the utilization of condenser waste heat for sublimation as a way of accelerating the drying rate. In addition, it also investigates the effect of internal cooling combined with vacuum cooling in the pressure reduction process. Jelly fish tentacles were used as the specimen, with different configurations for condenser heat waste and internal cooling valve opening. The results show that heating with condenser heat waste can accelerate the drying rate up to 0.0035 kg/m2.s. In addition, pre-freezing …
A New Experimental Approach To Evaluate Plasma-Induced Damage In Microcantilever,
2013
Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
A New Experimental Approach To Evaluate Plasma-Induced Damage In Microcantilever, Yuki Nishimori, Shinji Ueki, Masakazu Sugiyama, Seiji Samukawa, Gen Hashiguchi
Makara Journal of Technology
Plasma etching, during micro-fabrication processing is indispensable for fabricating MEMS structures. During the plasma processes, two major matters, charged ions and vacuum–ultraviolet (VUV) irradiation damage, take charge of reliability degradation. The charged ions induce unwanted sidewall etching, generally called as “notching”, which causes degradation in brittle strength. Furthermore, the VUV irradiation gives rise to crystal defects on the etching surface. To overcome the problem, neutral beam etching (NBE), which use neutral particles without the VUV irradiation, has been developed. In order to evaluate the effect of the NBE quantitatively, we measured the resonance property of a micro-cantilever before and after …
Observation Of Photovoltaic Effect And Single-Photon Detection In Nanowire Silicon Pn-Junction,
2013
Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
Observation Of Photovoltaic Effect And Single-Photon Detection In Nanowire Silicon Pn-Junction, Arief Udhiarto, Sri Purwiyanti, Daniel Moraru, Takeshi Mizuno, Michiharu Tabe
Makara Journal of Technology
We study nanowire silicon pin and pn-junctions at room and low temperature. Photovoltaic effects are observed for both devices at room temperature. At low temperature, nanowire pn-junction devices show their ability to detect single photon. This ability was not been observed for pin devices. Phosphorus-boron dopant cluster in the depletion region is considered to have the main role for single-photon detection capability. Fundamental mechanism of dopant-based single-photon detection in nanowire pn-junction is described in details.
Improvement In Performance Of Zno Based Dsc Prepared By Spraying Method,
2013
Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
Improvement In Performance Of Zno Based Dsc Prepared By Spraying Method, Rangga Winantyo, Devinda Liyanage, Kenji Murakami
Makara Journal of Technology
This paper reports the effect of TiCl4 on the performance of ZnO based DSC. ZnO was used due to its stability against photo-corrosion and photochemical properties similar to TiO2. Thin films of nanocrystalline ZnO were deposited on transparent conducting oxide glass using spray method. The ZnO films were treated using TiCl4. The cell’s efficiency was found to be 2.5% with TiCl4 post-treatment and 1.9% without TiCl4 post-treatment.
Influences Of Surface Morphology Of Nanostructured Rutile Tio2 Nanorods/Nanoflowers As Photoelectrode On The Performance Of Dye-Sensitized Solar Cell,
2013
Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
Influences Of Surface Morphology Of Nanostructured Rutile Tio2 Nanorods/Nanoflowers As Photoelectrode On The Performance Of Dye-Sensitized Solar Cell, Mohd Khairul Bin Ahmad, Kenji Murakami
Makara Journal of Technology
Aligned Rutile TiO2 nanorods (r-TNRs) and TiO2 nanoflowers (r-TNFs) were successfully prepared by hydrothermal method. Using hydrochloric acid (HCl) as chelating agent and titanium butoxide (TBOT) as precursor, aligned r-TNRs with r-TNFs were successfully growth onto fluorine-doped tin oxide (FTO) with different morphologies. The influences of surface morphologies to the rutile based Dye-sensitized solar cell (DSC) efficiency are discussed. The highest lightto- electric energy conversion efficiency, 1.80% is achieved using different concentration under simulated solar light illumination of 100 mWcm-2 (1.5 AM).
Fatigue Life Prediction Of The Keel Structure Of A Tsunami Buoy Using Spectral Fatigue Analysis Method,
2013
Department of Naval Architecture and Shipbuilding Engineering, Faculty of Marine Technology, Institut Teknologi Sepuluh Nopember (ITS), Surabaya 60111, Indonesia
Fatigue Life Prediction Of The Keel Structure Of A Tsunami Buoy Using Spectral Fatigue Analysis Method, Angga Yustiawan, Ketut Suastika, Wibowo Harso Nugroho
Makara Journal of Technology
One of the components of the Indonesia Tsunami Early Warning System (InaTEWS) is a surface buoy. The surface buoy is exposed to dynamic and random loadings while operating at sea, particularly due to waves. Because of the cyclic nature of the wave load, this may result in a fatigue damage of the keel structure, which connects the mooring line with the buoy hull. The operating location of the buoy is off the Java South Coast at the coordinate (10.3998 S, 108.3417 E). To determine the stress transfer function, model tests were performed, measuring the buoy motions and the stress at …
Production Optimization For Plan Of Gas Field Development Using Marginal Cost Analysis,
2013
Chemical Engineering Department, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
Production Optimization For Plan Of Gas Field Development Using Marginal Cost Analysis, Suprapto Soemardan, Widodo Wahyu Purwanto, Arsegianto Arsegianto
Makara Journal of Technology
Gas production rate is one of the most important variables affecting the feasibility plan of gas field development. It take into account reservoir characteristics, gas reserves, number of wells, production facilities, government take and market conditions. In this research, a mathematical model of gas production optimization has been developed using marginal cost analysis in determining the optimum gas production rate for economic profit, by employing the case study of Matindok Field. The results show that the optimum gas production rate is mainly affected by gas price duration and time of gas delivery. When the price of gas increases, the optimum …
Achieving High Strength And High Ductility In Friction Stir-Processed Cast Magnesium Alloy,
2013
Missouri University of Science and Technology
Achieving High Strength And High Ductility In Friction Stir-Processed Cast Magnesium Alloy, Wei Yuan, Sushanta K. Panigrahi, Rajiv S. Mishra
Materials Science and Engineering Faculty Research & Creative Works
Friction stir processing (FSP) is emerging as an effective tool for microstructural modification and property enhancement. As-cast AZ91 magnesium alloy was friction stir processed with one-pass and two-pass to examine the influence of processing conditions on microstructural evolution and corresponding mechanical properties. Grain refinement accompanied with development of strong basal texture was observed for both processing conditions. Ultrafine-grained (UFG) AZ91 was achieved under two-pass FSP with fine precipitates distributed on the grain boundary. The processed UFG AZ91 exhibited a high tensile strength of ∼435 MPa (117 pct improvement) and tensile fracture elongation of ∼23 pct. The promising combination of strength …
Effect Of Zinc Galvanization On The Microstructure And Fracture Behavior Of Low And Medium Carbon Structural Steels,
2013
Missouri University of Science and Technology
Effect Of Zinc Galvanization On The Microstructure And Fracture Behavior Of Low And Medium Carbon Structural Steels, Ignatius C. Okafor, Ronald J. O'Malley, Kaushal R. Prayakarao, Heshmat A. Aglan
Materials Science and Engineering Faculty Research & Creative Works
Microstructure and fracture behavior of ASTM 572 Grade 65 steels used for wind tower applications have been studied. Steels of two carbon level chemistries designed for this grade were used in the study. Fracture toughness of the steels was studied using 3-point bend test on samples coated with zinc and not coated with zinc. Lower carbon steel showed higher resistance to fracture than medium carbon steel after zinc galvanization. SEM study suggests that zinc and zinc bath additives that migrated to crack tips are responsible for the loss in ductility. The phenomenon of Liquid Metal Embrittlement (LME) is suggested to …
Influence Of Strain And Strain Rate On Microstructural Evolution During Superplasticity Of Mg-Al-Zn Sheet,
2013
Missouri University of Science and Technology
Influence Of Strain And Strain Rate On Microstructural Evolution During Superplasticity Of Mg-Al-Zn Sheet, A. Mohan, S. K. Panigrahi, R. S. Mishra, R. Verma
Materials Science and Engineering Faculty Research & Creative Works
Strain-induced abnormal grain growth was observed along the gage length during high-temperature uniaxial tensile testing of rolled Mg-Al-Zn (AZ31) sheet. Effective strain and strain rates in biaxial forming of AZ31 sheets also affected the nature of grain growth in the formed sheet. For the uniaxial testing done at 400 C and a strain rate of 10-1 s-1, abnormal grain growth was prevalent in the gage sections that experienced true strain values between 0.2 and 1.0. Biaxial forming of AZ31 at 5 x 10 -2 s-1 and 400 C also exhibited abnormal grain growth at the cross …
High-Speed Imaging Of A Bulk Metallic Glass During Uniaxial Compression,
2013
Bucknell University
High-Speed Imaging Of A Bulk Metallic Glass During Uniaxial Compression, Wendelin Wright, Rachel R. Byer, Xiaojun Gu
Faculty Journal Articles
High-speed imaging directly correlates the propagation of a particular shear band with mechanical measurements during uniaxial compression of a bulk metallic glass. Imaging shows shear occurs simultaneously over the entire shear plane, and load data, synced and time-stamped to the same clock as the camera, reveal that shear sliding is coincident with the load drop of each serration. Digital image correlation agrees with these results. These data demonstrate that shear band sliding occurs with velocities on the order of millimeters per second. Fracture occurs much more rapidly than the shear banding events, thereby readily leading to melting on fracture surfaces.
Microstructure And Mechanical Properties Of A Friction Stir Processed Ti-6al-4v Alloy,
2013
Missouri University of Science and Technology
Microstructure And Mechanical Properties Of A Friction Stir Processed Ti-6al-4v Alloy, Jianqing Su, Jiye Wang, Rajiv S. Mishra, Ray Xu, John A. Baumann
Materials Science and Engineering Faculty Research & Creative Works
Friction stir processing (FSP) trials were performed on 2mm-thick Ti-6Al-4V sheets using various processing parameters including tool rotational speed (800-1000RPM) and tool traverse speed (1-4IPM). A processing window was established with the W-1% La2O3 tool to produce defect-free friction stir processed (FSP'd) materials. The stir zone (SZ) material of the FSP'd samples showed a fully Β transformed microstructure characterized by typical basket-weave lamellar α/Β structure. The prior Β grains in the SZs contained multiple α variants, and the average sizes ranged from 12μm to 38μm influenced by the processing parameters. Based on metallurgical evaluation, the microstructural evolution …
Mechanical Properties And Microstructures Of Incoloy 909 Rolled Rings Subjected To A Modified Forging Cycle,
2013
California Polytechnic State University-- San Luis Obispo
Mechanical Properties And Microstructures Of Incoloy 909 Rolled Rings Subjected To A Modified Forging Cycle, Colin Lee Elliott Glaves
Materials Engineering
The microstructure of rolled rings of Incoloy 909 nickel-iron-cobalt superalloy subjected to a standard customer solution and aging treatment exhibited unacceptably large grains. Samples cut from a failed ring were mounted and polished for analysis. The samples were etched with a modified Kalling’s waterless reagent and metallographic analysis was done to identify characteristic large grain structures distributed among the desired smaller grain structures. The large grains were identified and noted for comparison to later samples. Two test rings were forged out of Incoloy 909 using revised forging procedures involving reduced soak temperatures before each forging step. Metallographic samples were cut …
The Effects Of Heat Treatment On The Grain Growth, Phase Evolution, And Hardness Of Newly Developed Steel-Based Hardfacing Alloys For Industrial Applications,
2013
California Polytechnic State University - San Luis Obispo
The Effects Of Heat Treatment On The Grain Growth, Phase Evolution, And Hardness Of Newly Developed Steel-Based Hardfacing Alloys For Industrial Applications, Renee Kuzniar
Materials Engineering
Steel-based hardfacing alloys are welded onto the outside diameter of tool joints in three beads with a slight overlap between welds for underground drilling to prolong the tool joints’ life. Current hardfacing alloys have a shortened life due to cracks occurring in neighboring weld beads. To decrease cracking, the effects of composition and heat treatment on the microstructure was investigated on five alloys. Five small arc-melt circular ingots roughly 1.4 x 0.3 inches were produced. Each sample had varying amounts of C, B, Cr, Mn, Mo, Nb, Si, Ti, V, and W. The carbon levels in the alloys were .91wt%, …
