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Full-Text Articles in Engineering

Cetirizine Dihydrochloride Tablets Comprising Two Different Lubricants With Highly Loaded Colloidal Silicon Dioxide, P. Katewongsa, T. Phaechamud Dec 2012

Cetirizine Dihydrochloride Tablets Comprising Two Different Lubricants With Highly Loaded Colloidal Silicon Dioxide, P. Katewongsa, T. Phaechamud

Journal of Metals, Materials and Minerals

Recently, the fast disintegrating tablet (FDT) has started gaining popularity and acceptance as new drug delivery system. Cetirizine dihydrochloride (CD) is the selective histamine (H-1)-receptor antagonist that is demonstrated to treat the symptoms associated with seasonal and perennial allergic rhinitis which this drug nowadays was prepared in form of FDT. Lubricant typically influences on tablet disintegration time (DT) and wetting time (WT). Therefore, it is important for optimizing the lubricant amount in this dosage form. The purpose of this study was to evaluate the effect of the lubricants (magnesium stearate (Mg-st) and sodium stearyl fumarate (SSF)) on the CD tablet …


Preparation And Characterization Of Highly Filled Graphite-Based Polybenzoxazine Composites, A. Pengdam, S. Rimdusit Dec 2012

Preparation And Characterization Of Highly Filled Graphite-Based Polybenzoxazine Composites, A. Pengdam, S. Rimdusit

Journal of Metals, Materials and Minerals

This research aims to study suitable preparation methods and to characterize highly filled graphite composites using polybenzoxazine as a matrix. The high loading of graphite filler was attained in the range of 40 to 80% by wt. due to the very low a-stage viscosity of the benzoxazine resin (BA-a) used. The suitable condition for the compression molding of the highly filled graphite-polybenzoxazine (PBA-a) composites was at temperature of 200°C, and pressure of 15 MPa in the hydraulic hot-press machine for 3 hours to assure a fully cured specimen. The densities of the obtained composites were found to be in a …


Effect Of Silicon On Subcritical Heat Treatment Behavior And Wear Resistance Of 16 Wt% Cr Cast Iron With 2 Wt% Mo, P. Kosasu, S. Inthidech, P. Srichareonchai, Y. Matsubara Dec 2012

Effect Of Silicon On Subcritical Heat Treatment Behavior And Wear Resistance Of 16 Wt% Cr Cast Iron With 2 Wt% Mo, P. Kosasu, S. Inthidech, P. Srichareonchai, Y. Matsubara

Journal of Metals, Materials and Minerals

Effects of Si content on the hardness, decomposition of austenite and abrasive wear resistance during subcritical heat treatment of hypoeutectic 16 wt% Cr -2 wt% Mo cast irons were investigated. The hypoeutectic 16 wt%Cr-2wt% Mo cast irons with 0.5-2.0 wt% Si were prepared. The as-cast specimens were heated up to subcritical temperatures at 50 K intervals from 673K for 14.4 ks ,28.8 ks and 43.2 ks and then, cooled to the room temperature by fan air cooling. In the as-cast state, the hardness increased gradually as Si content increased to 1.5 wt% and then decreased rapidly. The size and the …


Study Of Effect Of Temperature On The Synthesis Of Carbon Nanotubes By Floating Catalyst Method, R. Rajarao, B.R. Bhat Dec 2012

Study Of Effect Of Temperature On The Synthesis Of Carbon Nanotubes By Floating Catalyst Method, R. Rajarao, B.R. Bhat

Journal of Metals, Materials and Minerals

Carbon nanotubes (CNTs) were grown by floating catalyst method using acetylene as carbon precursor and ferrocene as catalyst precursor. The CNTs were grown in the temperature range of 700 - 1150C. The prepared CNTs were purified by acid treatment and air oxidation methods. The purified CNTs were characterized by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The purity of CNTs was determined by thermal analysis and X-ray diffraction method. The yield, diameter and length of grown CNTs were same at all temperatures. The crystalline perfection of CNTs increases as the temperature increases. Our results indicated that the synthesis …


Production Of Poly-?-Glutamic Acid By Bacillus Licheniformis: Synthesis And Characterization, N. Konglom, C. Chuensangjun, C. Pechyen, S. Sirisansaneeyakul Dec 2012

Production Of Poly-?-Glutamic Acid By Bacillus Licheniformis: Synthesis And Characterization, N. Konglom, C. Chuensangjun, C. Pechyen, S. Sirisansaneeyakul

Journal of Metals, Materials and Minerals

Poly-?-glutamic acid (?-PGA), one type of amino acid polymers, consists of D-and L-glutamic acids linked with amide bonding between ?-amino and ?-carboxylic acids. Naturally, ?-PGA could be biodegradable polymer and water-solubleapplied in various industries such as food, cosmetics, and pharmaceutical industries. Variation of initial L-glutamic acid concentration affecting on the production of ?-PGA by fermentation of Bacillus licheniformis was studied. The batch fermentation process consists of preparing the inoculum and expanding the culture of B. licheniformis into E medium (pH 6.5) for ?-PGA production. ?-PGA was recovered by using methanol precipitation together with lyophilization. For characterization, the molecular size of …


Influence Of Casting Techniques On Hardness, Tarnish Behavior And Microstructure Of Ag-Cu-Zn-Si Sterling Silver Jewelry Alloys, C. Chanmuang, W. Kongmuang, J.T.H. Pearce, T. Chairuangsri Dec 2012

Influence Of Casting Techniques On Hardness, Tarnish Behavior And Microstructure Of Ag-Cu-Zn-Si Sterling Silver Jewelry Alloys, C. Chanmuang, W. Kongmuang, J.T.H. Pearce, T. Chairuangsri

Journal of Metals, Materials and Minerals

The effects of Zn and Si on the hardness, tarnish resistance and microstructures of experimental Ag-Cu-Zn-Si alloy were investigated by means of vickers hardness, tarnish testing, optical and scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The various compositions of 935 sterling silver alloys produced by different casting techniques, investment (lost wax) process and metal mould casting, were compared. An induction casting machine with a vacuum system was used for investment casting at 1,025C with the mould temperature at 600C whereas a LPG/oxygen single flame tip torch was used for the metal mould process. Vickers hardness of the samples …


Polymeric Eutectic Drug Delivery System, S. Tuntarawongsa, T. Phaechamud Dec 2012

Polymeric Eutectic Drug Delivery System, S. Tuntarawongsa, T. Phaechamud

Journal of Metals, Materials and Minerals

Eutectic system is the mixture of at least two substances that suppresses melting point for each of them. The viscosity enhancement of liquid eutectic by polymer addition might increase the viscous environment for retardation of drug release. Typically, there are rare polymers that can dissolve in the liquid eutectic. The aim of this study was to develop the polymeric eutectic delivery system for controlling the drug delivery. Liquid eutectic used as vehicle was prepared by mixing menthol and camphor in various ratios. The obtained lowest viscosity liquid eutectic was used as vehicle in this study. Various polymers were attempted to …


Ballistic Performance Of Ceramic/S2-Glass Composite Armor, K. Dateraksa, K. Sujirote, R. Mccuiston, D. Atong Dec 2012

Ballistic Performance Of Ceramic/S2-Glass Composite Armor, K. Dateraksa, K. Sujirote, R. Mccuiston, D. Atong

Journal of Metals, Materials and Minerals

Ceramic composite armor was initially developed during the Vietnam War for use as helicopter armor and personnel armor. The requirements for the armor were light weight and the capability to defeat small caliber armor piercing (AP) projectiles. Several different ceramics were developed and tested for this application. It was found that aluminum oxide (Al2O3), silicon carbide (SiC) and boron carbide (B4C) had the best combination of properties to meet the requirements. The long term goal of this research is to develop domestic knowledge, design and production capability of ceramic composite armors. In this present research, the relationship between the ballistic …


The Effect Of Granule Morphology And Composition On The Compaction Behavior And Mechanical Properties Of 92% Alumina Spray Dried Granules, K. Somton, K. Dateraksa, D. Atong, R. Mccuiston Dec 2012

The Effect Of Granule Morphology And Composition On The Compaction Behavior And Mechanical Properties Of 92% Alumina Spray Dried Granules, K. Somton, K. Dateraksa, D. Atong, R. Mccuiston

Journal of Metals, Materials and Minerals

The compaction behavior and flexural strength of green compacts produced from four different types of 92% alumina spray dried granules were studied. Three of the granule types were produced in-house while the fourth is commercially-available. In addition, the decomposition behavior of the granules was studied by TGA in order to help explain the observed results. The morphology of the granules was observed using microscopy. Examination of the three granules produced in-house showed that they have several undesirable features; agglomeration, hollow granules and non-spherical granules. The morphology of the commercial granules showed them to be unagglomerated and spherical. The in-house granules …


Bismuth Vanadate (Bivo4) Powder Prepared By The Sol-Gel Method, P. Pookmanee, S. Kojinok, S. Phanichphant Dec 2012

Bismuth Vanadate (Bivo4) Powder Prepared By The Sol-Gel Method, P. Pookmanee, S. Kojinok, S. Phanichphant

Journal of Metals, Materials and Minerals

Bismuth vanadate (BiVO4) powder was prepared by the sol-gel method. Bismuth nitrate and ammonium vanadate were used as the starting precursors with mole ratio of 1:1 in ethanol at 70C for 1 hour. The obtained sol was changed to the yellow gel after addition of deionized water and acetic acid. The yellow gel was dried at 100C for 48 h and calcined at 400-600C for 2 hours. The phase of BiVO4 powder was studied by X-ray diffraction (XRD). The morphology of BiVO4 powder was investigated by scanning electron microscopy (SEM). The element composition of BiVO4 powder was indicated by energy …


Effect Of Milling Method On The Particle Size Of Calcined 0.65pmn-0.35pt Powder, A. Boonruang, P. Ngernchuklin, C. Eamchotchawalit Dec 2012

Effect Of Milling Method On The Particle Size Of Calcined 0.65pmn-0.35pt Powder, A. Boonruang, P. Ngernchuklin, C. Eamchotchawalit

Journal of Metals, Materials and Minerals

In this study, stoichiometric 0.65PMN-0.35PT powders have been prepared by columbite method. The perovskite single phase of PMN-PT was successfully synthesized after calcination of the mixed oxide at 900C/4hr. Due to the particle size of calcined powder has greatly effect on the electrical properties of sintered samples. Therefore, two different milling methods including high energy ball milling (HBM) and conventional ball milling (CBM) were used to grind the calcined powders. The results showed that the particle size distribution of calcined powders from HBM and CBM were 0.17 and 0.19 ?m, respectively. As a result, the relative density of the sintered …


Effect Of Zn Addition On Sol-Gel Derived Apatite/Wollastonite Glass-Ceramics Scaffolds, S. Tubsungneon Rattanachan, N. Srakaew, R. Pethnin, N. Suppakarn Dec 2012

Effect Of Zn Addition On Sol-Gel Derived Apatite/Wollastonite Glass-Ceramics Scaffolds, S. Tubsungneon Rattanachan, N. Srakaew, R. Pethnin, N. Suppakarn

Journal of Metals, Materials and Minerals

Bioactive glasses and glass-ceramics consisting of CaO-MgO-P2O5-SiO2 system have been shown to be bioactive, resorbable and to exhibit appropriate mechanical properties for bone tissue engineering applications. Bioactive glass-ceramics scaffolds consisting of zinc doped-apatite/wollastonite (AW) glassceramics were prepared by coating polyurethane foams with sol-gel derived glass gels. Density and compressive strength of the scaffolds decreased with increased in zinc contents. In vitro bioactivity of Zndoped AW glass-ceramics in a simulated body fluid (SBF) showed the formation of apatite layer on the surface within 7 days of soaking. However, increasing Zn addition increased the chemical durability of the AW glass-ceramics, resulting in …


Characterization And Drug Behavior In Shellac Wax Poloxamer Matrix Tablets Fabricated With Mold Technique, C. Choncheewa, T. Phaechamud Dec 2012

Characterization And Drug Behavior In Shellac Wax Poloxamer Matrix Tablets Fabricated With Mold Technique, C. Choncheewa, T. Phaechamud

Journal of Metals, Materials and Minerals

Shellac wax is a waste product from shellac manufacturing process and has not been reported to be used as pharmaceutical matrix base. This study was to prepared and characterized shellac wax - poloxamer 407 matrix tablet comprising hydrophilic or hydrophobic drug which were prepared by molten technique. The ratios of poloxamer 407: shellac wax was varied and subsequently loaded with the different drug content before characterized with differential scaning calorimetry (DSC), thermogravimetric analysis (TGA) and powder x-ray diffractometry (PXRD). Drug release study was also performed for 25 mg drug loaded matrix tablet in distilled water using dissolution apparatus II at …


Role Of Aluminum Monostearate On Heat Treated-Chitosan Sponges Properties, K. Yodkhum, T. Phaechamud Dec 2012

Role Of Aluminum Monostearate On Heat Treated-Chitosan Sponges Properties, K. Yodkhum, T. Phaechamud

Journal of Metals, Materials and Minerals

Heat treatment can be employed to modify properties such as biocompatibility and degradation rate of chitosan-based materials. However, heat treatment generally has effect on worsening of physical properties of the biomaterials. Our previous study indicated that fatty additive; aluminum monostearate (Alst), could improve thermal stability of chitosan sponges. Aim of this study is to investigate an effect of amount of Alst on physicochemical properties of chitosan sponges treated by different heat treatment methods. Two methods of heat treatment including moist heat (autoclave at 121°C, 15 psi for 5 minutes) and dry heat (vacuum heat at 110°C for 24 hours) were …


Study Of Dynamic Vulcanized Pla/Enr Tpv Filled With Various Organic Modified Mmt (Ommt), C. Thongpin, N. Kuttanate, K. Kampuang, N. Suwanwanit Dec 2012

Study Of Dynamic Vulcanized Pla/Enr Tpv Filled With Various Organic Modified Mmt (Ommt), C. Thongpin, N. Kuttanate, K. Kampuang, N. Suwanwanit

Journal of Metals, Materials and Minerals

In this research, we investigated the crystallization behavior of PLA and properties of PLA/ENR thermoplastic vulcanizates (TPVs). ENR was compounded with phenolic resin and with PLA at the blend ratio of 40/60 by using an internal mixer at 170°C and rotor speed of 70 rpm. Three types of organic modified montmorillonite (OMMT) which are Cloisite® 15A, Cloisite® 20 A and Cloisite® 30B were also added at various contents during mixing. The TPVs were pressed to form thin film in a compression molding machine and cooled down under pressure for 10 minutes. Crystallization behavior, thermal properties and morphology of TPVs were …


Thermal Degradation Of Pet Fabrics Coated With Interpenetrating Polymer Network-Silica Fume Mixtures, B. Kusuktham, S. Harburud, K. Srikulkit Dec 2012

Thermal Degradation Of Pet Fabrics Coated With Interpenetrating Polymer Network-Silica Fume Mixtures, B. Kusuktham, S. Harburud, K. Srikulkit

Journal of Metals, Materials and Minerals

Thermal degradation of polyester fabrics coated with interpenetrating polymer network (IPN) and silica fume (SF) was studied. Silica fume was modified with vinyltriethoxysilane (VTES) in order to improve its hydrophobicity and dispersibility in polymer matrix. Interpenetrating polymer network was prepared by sodium alginate (SA) mixed with 2-hydroxyethyl methacrylate (HEMA). Sodium alginate, HEMA, K2S2O8, N,N/ -methylenebisacrylamide, N,N,N/ ,N/ -tetramethylethylenediamine, and modified SF were mixed in aqueous solution with nonionic surfactant. In this condition, modified SF showed high dispersion ability in SA/HEMA solution. Additional, the application of 0.3 M CaCl2 onto PET surface and dried at temperature of 80o C for 1 …


Fabrication And Characterization Of Heterojunction For Cds Thin Films And Cualo2 Ceramic Pill Substrate, T. Gaewdang, N. Wongcharoen, A. Nopparuchikun, T. Wongcharoen, C. Poo-Rakkiat Dec 2012

Fabrication And Characterization Of Heterojunction For Cds Thin Films And Cualo2 Ceramic Pill Substrate, T. Gaewdang, N. Wongcharoen, A. Nopparuchikun, T. Wongcharoen, C. Poo-Rakkiat

Journal of Metals, Materials and Minerals

In this research paper, CdS thin films were deposited by thermal evaporation in vacuum on CuAlO2 ceramic pill substrate. From the data of I-V measurements at low temperature (20-300 K) the junction barrier height, ideality factor and series resistance values can be evaluated by using thermionic emission (TE) theory and Cheung's method. The junction barrier height and ideality factor were found to be strong temperature dependence. Evaluation of forward I-V data reveals a decrease in the zero-bias barrier height, but an increase in the ideality factor with decrease in temperature. In part of C-V measurements at room temperature, the obtained …


Preparation And Catalytic Property Of High Surface Area Mixed Oxides From Calcination Of Mgcucr- And Mgcual-Layered Double Hydroxides, W. Trakarnpruk Dec 2012

Preparation And Catalytic Property Of High Surface Area Mixed Oxides From Calcination Of Mgcucr- And Mgcual-Layered Double Hydroxides, W. Trakarnpruk

Journal of Metals, Materials and Minerals

In this research work layered double hydroxides (LDHs) containing Mg, Cu and Cr(or Al) were prepared with starting Mg:Cu:Cr (or Al) molar ratio of 2:1:1. They were calcined at 500 ºC for 5 h to convert into corresponding mixed oxides possessing high surface area. The catalysts were characterized by chemical analysis (ICP), infrared spectroscopy (FTIR), thermal analysis (TGA/DTA), powder X-ray diffraction (XRD), surface area measurements and H2 temperature programmed reduction (TPR). Catalytic property of these mixed oxides catalysts were tested in the oxidation of ethylbenzene using tertbutylhydroperoxide as an oxidant without added solvent. The experimental results show that high conversion …


Electrochemically Enhanced Plasticity Of Steels, Y.B. Unigovski, E.M. Gutman, Z. Koren, B. Borohov Dec 2012

Electrochemically Enhanced Plasticity Of Steels, Y.B. Unigovski, E.M. Gutman, Z. Koren, B. Borohov

Journal of Metals, Materials and Minerals

It is known that electrochemical surface treatment can decrease the residual stresses and the hardness of the surface layer as a result of the chemomechanical effect (CME), and also to improve the ability to plastic deformation, e.g., deep drawing for high strength alloys. The present research is aimed at using CME in order to improve such technological processes as rolling, deep drawing and other processes requiring an increase in the ductility of the metal surface layer using the hardness test assisted by electrochemical polarization. The hardness measurements were carried out using a microhardness tester equipped with a special three-electrode electrochemical …


Twin-Jet Electropolishing Of Cast Sterling Silver Alloys Using Perchloric Acid And Potassium Cyanide Solutions, W. Kongmuang, T. Chairuangsri, C. Chanmuang Dec 2012

Twin-Jet Electropolishing Of Cast Sterling Silver Alloys Using Perchloric Acid And Potassium Cyanide Solutions, W. Kongmuang, T. Chairuangsri, C. Chanmuang

Journal of Metals, Materials and Minerals

Twin-jet electropolishing of Ag-4.87 wt%Cu-0.79 wt%Zn-0.09 wt%Si alloy was studied. Two electrolytes, i.e. potassium cyanide solution in distilled water and glycerol-perchloric acid solution in absolute ethanol, were used in the experiments. Effects of parameters including voltage and electrolyte concentration have been studied. Surface of polishing specimens and artifact formed were characterized by light microscopy and electron microscopy. In general, the potassium cyanide solution is a better electrolyte than the glycerol-perchloric acid solution. A more uniform polishing can be obtained from the potassium cyanide solution at the voltage higher than 5 V. Increasing of the potassium cyanide concentration reduced the electrical …


Failure Analysis Of Bearings In Air Conditioning Compressor, P. Promdirek, A. Leidig, T. Keawjarus, P. Tong-In Jul 2012

Failure Analysis Of Bearings In Air Conditioning Compressor, P. Promdirek, A. Leidig, T. Keawjarus, P. Tong-In

Journal of Metals, Materials and Minerals

Two journal bearings of a compressor were failed in service. The wear which led to crack was observed at the internal surface of both bearings. The objective of this analysis is to evaluate the reason for the wear found on the internal bearings surface. Two bearings were returned from field and others in several conditions were examined. Electron probe micro analyzer and microhardness was used for metallurgical analysis. It revealed that bearing consisted of two different layers: 1) Fe-base and 2) Al-Sn alloy. Surface worn at the internal surface which composed of Al-Sn alloy was found. The results also showed …


Extraction Of Tin From Hardhead By Oxidation And Fusion With Sodium Hydroxide, C Bunnakkha, C Jarupisitthorn Jul 2012

Extraction Of Tin From Hardhead By Oxidation And Fusion With Sodium Hydroxide, C Bunnakkha, C Jarupisitthorn

Journal of Metals, Materials and Minerals

In this research work, the extraction of tin from tin-iron alloy or hardhead which is the intermediate product obtained during tin smelting was investigated. The hardhead containing 32.40 wt% Sn and 45.81 wt% Fe was ground to different sizes and oxidized at 500 to 800 °C for 1 to 6 hours to form SnO2 and Fe2O3. The results indicated that an increase in oxidation temperature decreased the required oxidation time. However using too high oxidation temperature (800 °C) resulted in sintering of the oxide product.In sodium hydroxide fusion stage, effects of fusion temperature, fusion time, NaOH quantity and oxide product …


Preparation Of Organosilane Treated Microcrystalline (Simcc) And Simcc/Polypropylene Composites, P. Thummanukitcharoen, S. Limpanart, K. Srikulkit Jul 2012

Preparation Of Organosilane Treated Microcrystalline (Simcc) And Simcc/Polypropylene Composites, P. Thummanukitcharoen, S. Limpanart, K. Srikulkit

Journal of Metals, Materials and Minerals

In this study, the silane treated microcrystalline cellulose (SiMCC)/polypropylene composite was prepared. In the first step, the surface modification of microcrystalline cellulose (MCC) with various concentrations of hexadecyltrimethoxysilane was carried-out in order to obtain the SiMCC having good compatibility with PP matrix. Characterizations including SEM, FT-IR, TGA and DSC were employed to analyze the structure of SiMCC. SEM revealed that MCC surface morphology was changed from rod shape into rough particles after silane treatment. In the next step, the obtained SiMCC was mixed with PP powder using twin-screw extruder. Based on TGA results, it was found that the addition of …


Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara Jul 2012

Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara

Journal of Metals, Materials and Minerals

Hypoeutectic 26 wt% Cr cast irons without and with Mo were prepared in order to investigate their abrasion wear resistance. The annealed specimens were hardened from 1323 K (As-H) and then tempered at three levels of temperatures between 673 and 823 K for 7.2ks, the temperature giving the maximum hardness (HTmax), lower temperature than that at HTmax (L-HTmax ) and higher temperature than that at HTmax (H-HTmax). The abrasive wear resistance was evaluated using Rubber Wheel abrasion test (three-body-type). It was found that hardness and volume fraction of retained austenite (V) in the heat-treated specimens varied with the Mo content …


Corrosion Behavior Of Aisi 4140 Steel Surface Coated By Physical Vapor Deposition, C. Keawhan, P. Wongpanya, N. Witit-Anun, P. Songsiriritthigul Jul 2012

Corrosion Behavior Of Aisi 4140 Steel Surface Coated By Physical Vapor Deposition, C. Keawhan, P. Wongpanya, N. Witit-Anun, P. Songsiriritthigul

Journal of Metals, Materials and Minerals

The corrosion behavior of uncoated and CrN-coated onto AISI 4140 steel was studied by electrochemical technique. Firstly, the AISI 4140 steel samples were solution heat treated and oil quenched in order to achieve proper hardness. Then, they were surface-prepared with alteration of surface roughness by using SiC paper at different numbers of 180, 600, and 1200 prior to CrN coating. The samples were coated with CrN film by physical vapor deposition (PVD) technique. The corrosion behavior of the uncoated and CrN-coated samples was studied in air-saturated 3.5 wt% NaCl solution at the pH values of 2, 7 and 10 at …


Tribological Behavior Of Austenitic Stainless Steel And Vanadium Carbide Coated By Trd Process, C. Lertlummeechai, P. Sricharoenchai Jul 2012

Tribological Behavior Of Austenitic Stainless Steel And Vanadium Carbide Coated By Trd Process, C. Lertlummeechai, P. Sricharoenchai

Journal of Metals, Materials and Minerals

In forming austenitic stainless steel sheet, galling is the major cause of tool steels failure. Coating on tool surface is an effective way to lessen galling tendency. In this paper, vanadium carbide coating by TRD process was conducted on tool steel and intentionally tempered in air to produce thicker vanadium oxide on vanadium carbide surface. Ring-on-disc wear test was conducted by sliding with austenitic stainless steel ring to investigate tribological behavior. Weight of ring was measured before and after wear tests. Chemical composition of ring surface was crosssection analyzed by EPMA. Surface of the disc was analyzed by XPS. Wear …


Low-Cycle Fatigue Of Thermally-Cycled Carbon-Epoxy Composite, Ya. B. Unigovski, A. Grinberg, E. M. Gutman, R. Shneck Jul 2012

Low-Cycle Fatigue Of Thermally-Cycled Carbon-Epoxy Composite, Ya. B. Unigovski, A. Grinberg, E. M. Gutman, R. Shneck

Journal of Metals, Materials and Minerals

Investigation of low-cycle fatigue of composites is of vital importance for the design of structural components. In this study, the effects of thermal cycling on low-cycle fatigue behavior of carbon-epoxy laminate are investigated in a purely bending mode at strain ratios of -1 and 0.1. It is found that a very small increase in the plastic strain amplitude catastrophically shortens the fatigue life N of the composite determined as a number of cycles corresponding to 0.9 of the initial force. The preliminary thermal cycling of the composite at the temperature varied from 180°C to −195.8°C shortens N values in comparison …


Porous Niti Produced By Nitita Transient-Liquid-Assisted Method, O. Worasub, A. Bansiddhi Jul 2012

Porous Niti Produced By Nitita Transient-Liquid-Assisted Method, O. Worasub, A. Bansiddhi

Journal of Metals, Materials and Minerals

This work presents a novel method for preparing porous NiTi by powder metallurgy using a vacuum sintering technique. Tantalum was used as a transient liquid phase creator, which enhanced the sinterability of NiTi powders. The effect of Ta content and powder packing on the degree of densification were investigated. The porous NiTi exhibited shape memory behavior and a large recovery strain, analyzed by differential scanning calorimetry and compressive testing, respectively, making the material promising for bone implant applications. In addition, macroporosity was created by using NaCl spaceholders. Adding 3 atomic percent of Ta and 60 volume percent NaCl space-holder resulted …


Corrosion Assessment Of Cast Aluminum Parts In Ethanol Fuel Blends, P. Wirot, J. Troset, W. Khonraeng, S. Mahabunphachai, E. Viyanit Jul 2012

Corrosion Assessment Of Cast Aluminum Parts In Ethanol Fuel Blends, P. Wirot, J. Troset, W. Khonraeng, S. Mahabunphachai, E. Viyanit

Journal of Metals, Materials and Minerals

Nowadays, the use of ethanol fuel blends in automobiles has become more and more worldwide since the ethanol mixture would enhance the performance of the engine and fuel economy ($/mile), while reducing the hazardous exhaust released to the environment. However, the use of ethanol fuel blends may induce some material compatibility issues on some automotive parts that were not designed to be used in contact with ethanol. In other words, the humidity in the ethanol would cause corrosion problem on these parts. The goal of this study is to assess the corrosion value of two cast aluminum parts in a …


Nr/Xsbr Nanocomposites With Carbon Black And Carbon Nanotube Prepared By Latex Compounding, A. Boonmahitthisud, S. Chuayjuljit Jul 2012

Nr/Xsbr Nanocomposites With Carbon Black And Carbon Nanotube Prepared By Latex Compounding, A. Boonmahitthisud, S. Chuayjuljit

Journal of Metals, Materials and Minerals

Two series of natural rubber/carboxylated styrene butadiene rubber (NR/XSBR) (80/20) nanocomposites containing different loadings of carbon black (CB) (3-9 phr) and carbon nanotube (CNT) (0.1-0.4 phr) have been prepared by a latex stage compounding method. Before mixing with NR/XSBR blended latex, CB and CNT were dispersed and stabilized in water by ball milling with the aid of surfactant. The obtained compounded latex was cast into sheet on a glass mold and thereafter cured in an oven at 80°C for 3 h. The tensile properties (tensile strength, modulus at 300% strain, elongation at break), dynamic mechanical properties (loss tangent, storage modulus) …