bluuebunny/crossref_metadata_2025 huggingface dataset:
A Bentonite Layer between Alumina Foam and its Hydroxyapatite Coat: An Improved Scaffold for Bone Tissue Engineering Applications
Authors: Shahabudin Nor Suhaida , Ahmad Zainal Arifin , Abdullah Norazharuddin Shah
Published: February 2015

It is arguable that successful bone tissue engineering (BTE) protocols relies heavily on scaffolds (i.e., for mechanical support, aid for 3D arrangement, allowing good nutrient and waste transport etc.). In this study, the consequence of adding a bentonite (B) layer between alumina foam (AF) and its hydroxyapatite (HA) coat scaffold is scrutinized by spatial characterization measurement (e.g., porosity, pore size, pore interconnectivity and compressive strength). Other than work on the said hydroxyapatite-bentonite coated alumina foam (HABCAF), spatial characterization efforts were also done for AF and HA coated AF (HACAF) scaffolds. Initially, AF scaffold was fabricated via the foam impregnation technique (FIT). Polyurethane (PU) foam was chosen as a template to ensure controlled porosity and guided pore interconnectivity within the resulting scaffold. HACAF and HABCAF are produced using AF scaffold skeleton, coated with HA and B (for HABCAF only) slurries of different viscosities. After drying and sintering stages, these scaffolds were tested. The results from composite coating show an increase of 40% in strength with the same pore size of PU foam. The HABCAF exhibited the highest compressive strength besides showing good interconnectivity and cell pores sizes (i.e., up to >500 μm). These results suggest that addition of B presents an interesting route in the making of good quality scaffolds for BTE applications.
Study of XRD and FESEM Characterization of Cellulose from Hardwood Waste of Resak (Vatica spp.)
Authors: Abidin Nurul Aimi Mohd Zainul , Azraaie Noriean , Ibrahim Nur Ain , Mamat Razali Nur Amira , Abdul Aziz Fauziah , Radiman Shahidan
Published: February 2015

Cellulose is one of the most abundant biomass material in nature extracted from natural fibers. Its hierarchical structure allows different kinds of microfibril cellulosic fillers to be obtained known as cellulose microfibril or microfibrillated cellulose (MFC). MFC is generally prepared by either acid hydrolysis, or chemical treatments, or by a high pressure refiner. In this study, attempts have been made to extract MFC from Resak’s hardwood waste (Vatica spp.) at atmospheric pressure using single-stage peroxyacetic acid delignification and Totally Chlorine-Free bleaching methods. The morphology structure of samples were characterized using Field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD).
Anode-Cathode Position: How it Influences the Radiation Risk to Staff Involved in Fluoroscopy Procedures
Authors: Salleh Husaini , Samat Supian , Matori Mohd Khalid , Md Isa Muhammad Jamal
Published: February 2015

It is important to understand that the heel effect contributes higher dose to cathode bound. This study is to verify this effect and consequently utilized it to minimize the radiation dose to staff involved in fluoroscopy procedures especially those using mobile C-arm unit. Water phantom with size of 20 x 30 x 30 cm was used in this study. It was exposed to x-rays from a mobile C-arm unit with auto brightness control (ABC) function. An ion chamber and a solid state detector were used to measure the scattered radiation and primary beam profile. Based on the result it was clear that scattered radiation measured was highest on the cathode bound side. Hence personnel involves in fluoroscopy procedure should avoid or spend the least possible time within this cathode bound area in order to lessen the radiation risk.
The Corrosion Attack on Stainless Steel 316L and WC-Co in High Sulphate-Chloride Ratio
Authors: Ismail Azzura
Published: February 2015

Austenitic stainless steels and cermets alloy has been used extensively in many sectors due to their highly resistance to corrosion attack and excel in mechanical properties. However, in corrosive media both materials are susceptible to corrosion attack especially in seawater and high temperature. Cermet alloys are a combination of ceramic and metal. Therefore, cermets exist in high corrosion resistance in aqueous media and the corrosion rate is complex to identify. This paper presents the corrosion mechanism of 316L and cermets alloy exposed to high concentration of sulphate in the salinity of seawater. The solution (media) was prepared according to the same composition as seawater including pH, salinity and dissolved oxygen. The corrosion mechanism were characterized to breakdown potential (Eb) of 316L which are the potential once reaches a sufficiently positive value and also known as pitting potential. This is the most point where localized corrosion susceptibility to evaluate and considered a potential, which could be an appropriate point according to any given combination of material/ambient/testing methods. The Eb value of 316L in high sulphate are higher compared to seawater in every temperature which elucidate that some anions accelerate corrosion attack whereas some anions such as sulphate behaves as inhibiting effect to 316L.
XRD Analysis of Al-6vol%SnPb Composites Fabricated by Cold Forging Process with Various Sintering Temperatures
Authors: Zakaria Marwan , Karim Siti Rodiah , Badarulzaman Nur Azam
Published: February 2015

This paper focused on fabrication of Al-6vol%SnPb from recycled Aluminium and recycled solder and its characterization in different sintering temperature. Al-20SnPb was fabricated by using cold forging process of flakes chip raw materials. Constant pressure (56.4 MPa) was used to implement cold forging process. Various sintering temperature (200 0C, 250 0C, 300 0C and 3500C) was studied to obtain the optimum hardness properties. The diffraction pattern of X-Ray diffraction (XRD) reveals the influence of varying sintering temperature of Al-6vol%SnPb. Vickers hardness result also support that, optimum result obtained is at sintering temperature 300 °C.
Lattice Strain, Crystallite and Microstructure Studies of SiC Irradiated by Electron Beam
Authors: Abdullah Yusof , Yusof Mohd Reusmaazran , Zali Nurazila Mat , Megat Ahmad Megat Harun Al Rashid , Abdul Azam Farah ‘Atiqah
Published: February 2015

Silicon carbide (SiC) is an important material that has the potential to be used in the nuclear industry. The surface of 0001 silicon carbide, 4H polytype wafer has been irradiated by electron accelerator at the accelerator voltage of 3 MeV and 10 mA beam current. Samples were irradiated to dose received of 1000 kGy, 1500 kGy and 2000 kGy. Characterization of the samples have been done using X-ray diffraction (XRD) and scanning electron microscopy (SEM) to investigate the electron irradiation effect on structure as well as current-voltage tests to study electrical property.
Study on Indoor Formaldehyde Neutralization by Using Anatase and Rutile Nanotitania
Authors: Aqilah Sapiee , Meor Sulaiman Meor Yusoff , Mahdi E.M. , Siti Salwa Z.A.
Published: February 2015

Resin impregnated wooden furniture is one of the major sources of formaldehyde in homes from the use of urea-formaldehyde and phenol-formaldehyde resins as adhesives. Indoors, emission of formaldehyde is accelerated by heat and humidity. Dehumidifiers and air conditioners are recommended to improve indoor air quality but the maintenance is costly and relative humidity in some areas are difficult to control. Due to small band gap energy and large surface area, nanotitania could neutralize formaldehyde gas by photocatalytic phenomenon. A study was carried out to investigate the formulations of pure anatase, pure rutile and mixed rutile and anatase phases which can neutralize formaldehyde within a short time. Comparative study was then performed with a control and the result showed that for the control, there are still significant amount of formaldehyde present after running the sample for one hour.
Effects of Hydrothermal Duration on Synthesized Zeolite Rice Husk Particles
Authors: Rosman Nurafiqah , Harun Zawati
Published: February 2015

Zeolite particles were synthesized through in-situ extraction of silica from rice husk ash without seeding method in the absence of organic template by a static hydrothermal condition at various duration for 8, 12, and 24h. The effect amorphous silica content on hydrothermal duration of synthesis products was evaluated with X-ray diffraction (XRD), and field emission microscopy (FESEM). The present of zeolite Y without seeding method via XRD analysis show a mixture of zeolite A, Y and P. The transformation of amorphous rice husk particle was increased gradually with the increased of hydrothermal reaction. The FESEM images showed agglomerated cubic-shaped morphology of the powders with increase in crystallization reaction. .
Temperature Programmed Desorption of Carbon Dioxide for Activated Carbon Supported Nickel Oxide: The Adsorption and Desorption Studies
Authors: Hakim Azizul , Wan Isahak Wan Nor Roslam , Abu Tahari Maratun Najiha , Yusop Muhammad Rahimi , Mohamed Hisham Mohamed Wahab , Yarmo Mohd Ambar
Published: February 2015

The priority of success in practical CO2 capture with solid sorbents is dependent on the development of a low cost sorbent and energy consumption for regeneration with high adsorption capacity. In this work, different loading of NiO were evaluated as a potential source of basic sites for CO2 capture, and activated carbon (AC) was used as a preliminary support in order to study the effect of the impregnation. The NiO loading increased the basicity of the adsorbent significantly enhance the CO2 chemisorption. Nonetheless, it drastically reduced the surface area of the AC, which is chiefly responsible for CO2 physisorption, thus decreasing the carrying capacity of ACs at room temperature and pressure.
Formation of Aligned Iron Oxide Nanopores as Cr Adsorbent Material
Authors: Rozana Monna , Razak Khairunisak Abdul , Kawamura G. , Matsuda Atsunori , Lockman Zainovia
Published: February 2015

Elongated iron oxide nanopores (FNPs) were fabricated by anodisation of iron in fluoride-ethylene glycol (EG) added to it 1 ml, 1 M KOH electrolyte at three different voltages: 30 V, 40 V and 50 V. It was observed regardless of the voltage applied; the nanopores seem to be separated from one to another at the bottom part of the anodic film forming rather discreet nanotubular structure at this region. X-ray diffraction (XRD) was used to evaluate the phases present within the anodic layer. γ-FeOOH, Fe (OH)2, and FeF5.H2O were detected in all samples. However, when the anodisation voltage was increased, peaks from the FeF5.H2O are more intense indicating either more F- insertion in the anodic layer or crystallization of this phase at higher voltage. After annealing, XRD detected only hematite; α-Fe2O3 and magnetite; Fe3O4 indicative of phase formation or transformation had occurred during the annealing process. The annealed samples displayed an ability to adsorb Cr (VI) with almost 30 % reduction of the Cr (VI) concentration after 5 hours of exposure to the nanoporous anodic film.
Properties of BaZrxTi1-x O3 Thick Film Deposited Using EPD Method
Authors: Razak Khairunisak Abdul , Khoo Fei San , Sreekantan Srimala , Lockman Zainovia
Published: February 2015

Barium zirconate titanate, BaZrxTi1-xO3, (BZT) with x compositions have been widely studied as a potential candidate for antenna application. In this study, BZT film was prepared using the electrophoretic deposition (EPD) method. The EPD method was used to produce BZT composite into film for miniaturization purposes and dielectric properties improvement. The EPD process was performed with varying pH, voltages, deposition time and amount of Zr. The results showed that optimum deposition time was obtained at pH 4, 90V and 1 minute deposition time. Increasing Zr content decreased the dielectric constant of the BZT composite, and increased the loss tangent of the samples. The result is in agreement with microstructure observation that Zr addition in BZT decreased the grain size that suppressed the dielectric properties. This makes BZT is a suitable candidate for antenna application.
Microstructure Evolution of Conventional and Semi-Solid A356 Alloy with Addition of Strontium
Authors: Seo Yuan Sieng , Nasir Laila Masrur Mohd , Hussain Zuhailawati , Anasyida Abu Seman
Published: February 2015

In this study, modification of aluminium silicon eutectic alloy by grain modifier, strontium was investigated on conventional and slope cast A356 alloy. A356 alloy with addition of 0 to 0.97 wt.% Sr was prepared by conventional and slope casting in melting furnace. The molten metal of A356 alloy was casted into steel mould. Microstructure was observed using SEM. Phase analysis was done using XRD. Microhardness was conducted using Vicker microhardness. Microstructure of conventional cast displayed dendritic structure whereas slope cast displayed globular structure. Addition of Sr refined eutectic structure in both conventional and slope cast alloy. Phase analysis revealed the presence of Al2Sr phase in conventional cast Al-6Si-0.97Sr. Microhardness of the conventional cast alloy decreased with increasing of Sr up to 0.97 wt.%.
Effect of Cu-Excess on the Microstructure and Microwave Dielectric Properties of CaCu3Ti4O12 Ceramics
Authors: bin Abu Mohamad Johari , Mohamed Julie Juliewatty , Ain Mohd Fadzil , Ahmad Zainal Arifin
Published: February 2015

CaCu(3+x)Ti4O12 (CCTO) ceramics with different Cu-excess (x = 0 – 0.6) were prepared by conventional solid-state reaction method. Characterization of the prepared ceramics with XRD and FESEM showed that lattice parameter and grain size are slightly increased, indicating Cu-excess to have the big impact on the both phase structure and microstructure. The XRD profiles indicated that the secondary phase (CuO or Cu2O) existed at edge/corner of CCTO grain, which promoted inhibited grain growth behavior. The CCTO ceramics exhibited two trends of dielectric constant related to frequency, which showed a flatter curve about ~50 in 1 – 25 GHz regions, and it’s dropped rapidly to ~35 in 25 – 50 GHz region. With Cu-excess, the dielectric constant of the ceramics was increased for an average of a quarter-order of magnitude, while the tangent loss also increased up to triple times than x = 0, for the same frequency range. Despite enormous increase of dielectric constant related to varying Cu-excess, the tangent loss also increased.
Temperature Programmed Reduction and X-Ray Diffraction Studies of Fe2O3 Reduction by Different Concentration of Carbon Monoxide
Authors: Tengku Shafazila , Samsuri Alinda , Salleh Fairous , Othaman Rizafizah , bin Kassim Mohammad , Mohamed Hisham Mohamed Wahab , Yarmo Mohd Ambar
Published: February 2015

Reduction of Fe2O3 by carbon monoxide (CO) have been studied by temperature programmed reduction (TPR) and X-ray diffraction spectroscopy (XRD). The influences of carbon monoxide concentration on the reducibility of iron oxides have been investigated. This study deals with the comparison in the reduction of Fe2O3 between 5% to 20% of CO concentration in the temperature range of 40–900 °C. The result shows that reducing behaviour of Fe2O3 is strongly dependent on the concentration of CO. It is suggested by using 20% of CO complete reduction takes place at lower temperature due to absence of intermediate FeO giving only two-steps reduction (Fe2O3 → Fe3O4 → metallic Fe). Moreover, excess of CO results the formation of iron carbide phase.
Tensile Behaviour and Fracture Characteristics of Polydimethylsiloxane (PDMS) Filled Silica Composites
Authors: Azmi Mohd Azham , Yahya Sufiah Mohamad , Ahmad Sufizar , Taib Hariati
Published: February 2015

The focus of this study is to investigate the mechanical properties and fracture behaviour of polydimethylsiloxane filled crystalline silica composites (PDMS/CS) upon tensile loading. The PDMS/CS composites were fabricated by using casting method and cured at room temperature for 24 hours. Crystalline silica (CS) were added to PDMS at compositions of 2, 6, 10 wt%. The tensile properties of PDMS/2wt%CS showed that the tensile stress were improved by 4.3%. Fracture behaviour as determined by the characteristic of fracture surface of pure PDMS and PDMS/CS composites were analysed using Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). Observation via FESEM and AFM indicated different fracture characteristic of filled PDMS and unfilled PDMS. The addition of CS as fillers were indeed proven to improve the strength of the composites.
Reduction of MoO2 to Metallic Molybdenum via Carburization and Thermal Process
Authors: Samsuri Alinda , Tengku Saharuddin Tengku Shafazila , Salleh Fairous , Mohamed Hisham Mohamed Wahab , Othaman Rizafizah , Yarmo Mohd Ambar
Published: February 2015

A metallic molybdenum is formed by a two-stage process that was carburized MoO2 with carbon monoxide followed by heat treatment. XRD techniques were employed to identify the phase’s changes in the sample. It was found that by the present of carbon monoxide during carburization process until 900 °C, Mo2C is formed first, compared to metallic molybdenum, due to the high thermodynamic barrier for formation of metallic molybdenum. In the second stage, Mo2C further reacts with the remaining MoO2 at 900 °C to produce metallic molybdenum.
Morphological Analysis of SS316L Foam Produced by Using Slurry Method
Authors: Mad Rosip N.I. , Ahmad Sufizar , Jamaludin Khairur Rijal , Mat Noor Fazimah
Published: February 2015

Metal foams had been developed years ago by researchers. There were various methods used to produce metal foam such as slurry, compaction, gas entrapment technique and casting methods. In this study, slurry method used to produce SS316L foam with powder compositions 50wt%, 55wt% and 60wt%. Polyethylene Glycol (PEG) and Carboxyl Methyl Cellulose (CMC) were used as binder which was mixed with SS316L powder and distilled water. Polyurethane (PU) foams were impregnated with slurry by pressed out to cover every pores and struts of PU foams. Then, the coated PU foams were dried in the oven for 24 hours at 30°C, followed by sintering process in the vacuum furnace at three different temperatures which were 1200°C, 1250°C and 1300°C. There were Oxygen, Aluminium, Calcium, Silicon, Chromium, Nickel, Ferrous and Molybdenum elements found in the SS316L foams.
Potential of Eggshell Waste for Pyrolysis Process
Authors: Rohim Rohazriny , Ahmad Razi , Ibrahim Naimah , Hamidin Nasrul , Abidin Che Zulzikrami Azner
Published: February 2015

The eggshell waste which has potential mineral such as calcium oxide (CaO) was studied for biomass pyrolysis in a fixed bed reactor. The objective of this study was to characterize the CaO from waste eggshell and correlated the potential in pyrolysis process. Raw eggshells were analyzed by thermal gravimetric analyzer (TGA). Then, they were calcined at the temperature of 900oC for 1 hour with nitrogen gas. Raw and calcined eggshell were characterized by x-ray fluorescence (XRF). Non-catalytic and catalytic pyrolysis were done in the optimum pyrolysis condition with eggshell as a catalyst. XRF results showed that the percentage of CaO in raw eggshell was increased in calcined eggshell. Bio-oil product yield increased by 25.98% by using eggshell waste as a catalyst. CaO from waste eggshell improved the production of bio-oil in terms of quantity.
Development of Stainless Steel (SS316L) Foam with Different Composition Using Compaction Method
Authors: Mahammad Rafter Murni Faridah , Ahmad Sufizar , Ibrahim Rosdi , Hussin Rosniza , Taib Hariati
Published: February 2015

Powder metallurgy stainless steels are retains unique benefits in preparation of porous metals due to its low cost, better wear, precise size control and corrosion resistance which are significant quality displays. In this study, the fabrication of open cellular stainless steel (SS316L) foams by using a crystalline sugar via compaction method was investigated. In this work, we show a promising method of SS316L preparation with crystalline sugar as space holder particles. Then, the foams will be given to consider the properties of SS316L foam after sintering process. Powder metallurgy process needs to go through the mixing, pressing, sintering and analysis. The selected composition of SS316L was 50 wt % and 55 wt % SS316L while the remaining percentages are foaming agent or binder. Then, sintering process was conducted in the tube furnace. The SS316L foams were characterised using X-Ray Diffraction (XRD) and Energy Diffraction X-ray (EDX). The results of this study indicate that, the XRD was detected Austenite stainless steel. Then, the detected elements in the SS316L foam were O, K, Mn, Cr, Fe, Mo and Al.

 
Production of Cobalt Chromium Molybdenum (CoCrMo) Foam by Replication Method
Authors: Abdul Manaf Nur Suliani , Ahmad Sufizar , Ibrahim Rosdi , Kamdi Zakiah , Ismail Azzura
Published: February 2015

Cobalt Chromium Molybdenum (CoCrMo) generally known as a highly resistant to corrosion and wear performance. CoCrMo was prepared using replication method. The aim of this paper is to producing CoCrMo foam that will be given to consider the properties of CoCrMo foam after sintering process. The CoCrMo slurry was produced by mixing CoCrMo powder with Polyethylene Glycol (PEG), Carboxyl Methyl Cellulose (CMC) and distilled water. The polymeric foam template was impregnated in CoCrMo slurry and dried at room temperature. Sintering was carried out in a high temperature tube furnace at 1300°C. After the sintering process, the microstructure of the CoCrMo foam produced was observed by Scanning Electron Microstructure (SEM) and the elemental analysis was carried by Energy Dispersive X-ray Spectroscopy (EDS). While, X-Ray Diffraction (XRD) is used to characterize the chemical composition and structure of the samples. The EDS analysis performed in all samples with composition of 65 wt % CoCrMo foam show the presence of of Cr, Mo, Co, Mn, C, O, Al, Si and Ca. From the XRD results, the pattern that was detected all the peak was PDF 2007: 00-041-0943(Cobalt Nitride).
X-Ray Diffraction, Spectroscopic and Morphological Studies of Electrochemically Synthesized Copper(II) Palmitate Complex
Authors: Nordin Norazzizi , Samad Wan Zurina , Liew Kin Hong , Yarmo Mohd Ambar , Yusop Muhammad Rahimi , Othman Mohamed Rozali
Published: February 2015

Copper (II) palmitate complex was synthesized using an electrochemical technique in the presence of palm-based palmitic acid as the ligand and Cu (II) ions from the slow released of anode material through the electrochemical oxidation of Cu foil. The system consisted of Cu foil and a graphite rod as the anode and cathode, respectively, while ammonium acetate was used as a supporting electrolyte. X-ray diffraction and spectroscopic studies were carried out to characterize the synthesized complexes using powder XRD, XPS, FTIR and UV-Vis. The results obtained showed that the desired Cu (II)Pa complex was successfully synthesized using the electrochemical technique. The surface morphology of the complexes was analyzed using FESEM, and the micrograph obtained showed that the synthesized complexes formed nanosized matchstick-like structures. This conclusion is supported by the TEM micrograph which shows the presence of nanoparticles with different diameter ranges from 2 to 3 nm.
Effect of Thermal Annealing on La2O3 Films Grown by Plasma Enhanced Atomic Layer Deposition
Authors: Liu Jian Shuang , Zhu Fang Fang , Lu Fei , Zhang Lin
Published: February 2015

A plasma enhanced atomic layer deposition process has been demonstrated for Lanthanum oxide films using La (thd)3 precursor and oxygen plasma. The chemical and electrical properties of La2O3 ultra-thin films on Si (100) substrates before and after post-annealing in N2 ambient have been investigated. X-ray photoelectron spectroscopic revealed that interface reactions take place after annealing process which lead to oxygen insufficiency, as well as the balance band offset decreases with the increase of annealing temperature. The capacitance-voltage and current-voltage characteristics show La2O3 capacitors annealed at 900 °C have negligible hysteresis, smaller interface trap density in comparison with as-deposited samples, but larger flat band voltage and higher gate-leakage current density due to the appearance of oxygen vacancy in the La2O3 films.
Effect of Oxygen Content in Powders on Microstructure and Mechanical Properties of WC-FeAl Composites Fabricated by Vacuum Sintering Technique
Authors: Furushima Ryoichi , Katou Kiyotaka , Shimojima Koji , Hosokawa Hiroyuki , Matsumoto Akihiro
Published: February 2015

WC-FeAl composites were fabricated by vacuum sintering technique from mixture of WC and FeAl powders containing various oxygen content. Mechanical properties such as hardness, fracture toughness and transverse rupture strength were influenced by the oxygen content in the powders. Control of the oxygen content was succeeded by changing the powder preparation process. Contrary to expectations, the reduction of oxygen content led to degrade the fracture toughness and transverse rupture strength of the composites. This result was attributed to the microstructural change in the sintered composite. The sintered composite of lower oxygen content exhibited WC grain growth or inhomogeneous microstructure, which can be the cause of degradation of those mechanical properties. It was concluded that the oxygen content was one of the key factors to influence the microstructure or mechanical properties of WC-FeAl composites.
Influence of Chlorine Additives on Combustion Rate of Pulverized Coal Injection
Authors: Wu Bingqiang , Zhang Shu Hui , Liu Xiao Jie , Qie Ya Na , Lv Qing
Published: February 2015

Chlorine additives are often used to improve the combustion performance of pulverized coal injection (PCI) in blast furnace. The influence of chlorine additives on pulverized coal combustion rate was analyzed and the micrograph of unburned pulverized coal (UPC) was observed by SEM in order to analyze the influence mechanism of chlorine additives. The results show that proper addition amount of CaCl2, NaCl, MgCl2 and FeCl3 respectively promotes pulverized coal combustion in different degrees. The average size of UPC is smaller and the micrograph becomes irregular when the chlorine additives are increased. While beyond the appropriate addition amount, the combustion rate of PCI reduces. During the combustion process of pulverized coal with chlorine additives, HCl is produced which prevents the combustion process.
Removal of Paraquat from Aqueous Solutions Using Multi-Walled Carbon Nanotubes: Kinetic, Isotherm and Thermodynamic Studies
Authors: Hao Han , Feng Jian Guo , Liu Wen Jun , Wu Xue Min
Published: February 2015

Multi-walled carbon nanotubes (MWCNT) were used as an efficient adsorbent to remove Paraquat (PQ) molecules from its aqueous solutions. The initial PQ concentration, adsorption time and temperature had considerable effect on the removal of PQ onto MWCNT. The adsorption of PQ onto MWCNT followed the pseudo second-order kinetic model involving the particle-diffusion mechanism. The adsorption isotherms were fitted by the Langmuir isotherm, with the maximum adsorption capacity based on the former of 79.365 mg·g-1. Thermodynamic parameters, including Gibbs free energy changes (ΔG0), as well as changes in enthalpy (ΔH0) and entropy (ΔS0), were also calculated. The results demonstrated that PQ was adsorbed onto MWCNT spontaneously and endothermically in nature.
Welding-Brazing Characteristic in Electron Beam Joining Vanadium Alloy and Stainless Steel
Authors: Wang Ya Rong , Yu Yang , Zhang Wei Chao
Published: February 2015

The high vacuum electron beam welding-brazing was used to joining vanadium alloy (V-5Cr-5Ti) with stainless–steel (HR-2). The temperature fields and stress distributions in the V-5Cr-5Ti/HR-2 joint during the welding process were numerically simulated and the effect of the electron beam off-set distance was studied. The results show that the accurate heat input and proper molten pool position can help to control the fusion ratio of the V/Fe. The electron beam should off set on the stainless steel side rather than vanadium alloy side, and the best range of the distances off-set is 0-0.5mm. The residual stress appears to be bimodal and asymmetric. The maximum lateral residual tensile stress reached 388MPa at the V-5Cr-5Ti side. The joints with the characters of welding and brazing and the metallurgically bonded joint was achieved with 0.3mm beam off-set. With the liquid-to-solid interalloying of dissimilar materials controlled well, a reaction zone is gained on the interface. The maximum tensile strength of vanadium alloy/stainless-steel dissimilar alloy jointswas up to 200MPa with no defect.
Study on Clinching for Similar and Dissimilar Titanium Alloy
Authors: Ding Yan Fang , He Xiao Chong , Zhao Lun
Published: February 2015

Adopting experimental method to examine clinching is able to apply to the joining of similar and dissimilar titanium alloy in this study. Also, to use tensile-shear test to figure out mechanical properties of clinched joints to TA1-TA1 clinched joints and Al5052-TA1 clinched joints. The results show that average load of TA1-Al5052 clinched joints is largely lower than the average load of TA1-TA1 clinched joints. Average load of TA1-TA1 is around 4427.58, equal to 3.85 times to Al5052-TA1.The two types of fractured joints are all neck shear fracture of the upper sheets. Therefore, the strength of joints is dependant to the material of the upper sheet. The formability of TA1-TA1 clinched joints are superior to Al5052-TA1, and average displacement of TA1-TA1 clinched joints is about 1.23 times to Al5052-TA1 clinched joints.
The Effect of Enhanced Solution Treatment on Microstructures and Properties of 6013 Type Aluminum Alloy
Authors: Zhang Fu Bao , Tang Tong Ming , Zhao Yu Feng , Xu Xiao Jing , Ju Zhi Lan , Hua Guo Ran
Published: February 2015

The effect of enhanced solution treatment on microstructures, tensile properties, intergranular corrosion and exfoliation corrosion of a 6013 type aluminum alloy proceeded via various solution treatment were investigated by optical microscopy (OM), scanning electron microscopy (SEM), tension testing and corrosion resistance testing. The results show that compared with the conventional solution treatment (560°C×2 h), the enhanced solution treatment (560°C×2 h+570°C×2 h) can improve ultimate tensile strength and elongation, the corrosion resistance become worse after 151°C×8 h+191°C×8 h artificial aging. The tensile strength increase is believed to resulting from the coarse second phases dissolve. The corrosion resistance decrease is due to grain growth.
The Influence of Calcium Additive in the Structural Formation of Tungsten via Reduction Reaction
Authors: Yang Xin , Tan Dun Qiang , Li Ya Lei , He Wen , Zhu Hong Bo , Lu Lei , Lu De Ping
Published: February 2015

With the processes of solution doping and hydrogen reduction process, the raw materials APT powder was converted into the tungsten with calcium additive. Micro-morphology, micro-structure, the existing form of element calcium and their distribution were examined by SEM, HRTEM and EDS. The results show that Element calcium is mainly in the form of CaWO4 in tungsten oxide powder and has two calcium tungstate forms which are CaWO4 and Ca4.26W10O30 in reducing tungsten powder. The Ca-W-O particles are embedding in the tungsten powder particles; the rest distribute between the tungsten powder particles.
Environmental Effects on Electrochemical Behaviors of Materials of a Dissimilar Metal Weld Exposed to High Temperature Primary Water of PWR Nuclear Power Plants
Authors: Li Guang Fu , Fang Ke Wei , Xu Jun
Published: February 2015

The effects of environmental factors on the electrochemical behaviors of the materials 52M and 316L taken from a dissimilar metal weld exposed to high temperature primary water of pressurized water reactor (PWR) nuclear power plants were studied experimentally, mainly on the effects of impurities chloride and sulfate in water, temperature and dissolved oxygen on the polarization curves, in order to provide fundamental data for relevant research and development. The results showed that doping chloride and sulfate into the water caused the rise of the tendency to pitting and general corrosion tendencies of both materials. With the rise of temperature from 160 °C to 290 °C, the tendencies to corrosion in anodic condition increased. The rise of the dissolved oxygen led to the rises of both the corrosion potentials and also the tendencies to corrosion.
Research on Microstructure and Properties in Welded Joint of 700 MPa Grade Low Carbon Micro-Alloy Steel
Authors: Gu Jian Feng , Xiao Yi , Zhou Kai Jun , Dai Dong Dong , Zhong Qing Dong
Published: February 2015

Microstructure and mechanical properties of automobile beam used BS700MC low carbon micro-alloy steel welding joint were investigated by cold crack sensitivity, microhardness test, bending, impact, tensile and metallographic analysis. The results showed that the BS700MC steel has better crack resistance, and without heat treatment before welding with the WH80-G welding wires. The microstructure of joint’s weld seam is acicular ferrite, very little bainite and proeutectoid ferrite. The hardness value of weld seam zone is 380 HV and is the same as that of base metal. But the lower of weld joints rigidity has obvious fluctuations, and the HAZ appears softened phenomenon. The welding joint has good impact toughness only between 20 and minus 20 degrees Celsius.The tensile strength of BS700MC welded joint reaches 815 MPa, 97.1% of base metal, fracture position in HAZ. Tensile fracture morphology is mixed type indicating dimple and cleavage steps, and welding joint have good comprehensive mechanical properties.
Hot Deformation Behavior of Q235 Steel during Isothermal Compression at Elevated Temperature
Authors: Yang Ben , Zheng Zhou , Wang Li Xin , Wu Yong Gang
Published: February 2015

The isothermal hot compression tests of Q235 steel over a wide range of temperatures (1023-1123 K), strain (0.7) and strain rates (1、5、10 s−1) were performed on Gleeble-1500 system. The results show that when the deformation temperature is constant, as the strain rate increases, the flow stress also increases; Use the JC model to establish constitutive relation equation with true stress-true strain curve. And compare the prediction value of the constitutive relation equation with the experimental values, the relative error between the two is within the allowable range, indicating that the JC model constitutive relation equation applicable for the thermal deformation of Q235 steel.
XRD, STEM, and Tensile Properties of AISI S1 Tool Steel after Deep Cryogenic Treatment
Authors: Vahdat Seyed Ebrahim , Niaki Keyvan Seyedi
Published: February 2015

Successful employment of advanced tool steel in engineering applications is related to its ability in terms of meeting service life requirements and fabrication with proper dimensions. Deep cryogenic treatment may be used to produce advanced tool steel by simultaneously increasing toughness, strength, and hardness. Twelve sets of specimens were tested in this paper, 9 of which were deep cryogenic treated and then tempered. Tensile properties, hardness, X-ray diffraction, and scanning transmission electron microscopy were applied for macroscopic and microscopic investigations. The best results of simultaneous improvement in toughness, hardness, and strength were obtained for 36 h soaking time and 1 h tempering time.
Research on the Morphological of Lead and Zinc in the Smelting Slag
Authors: Yu Lin , Li Dong Wei
Published: February 2015

In this paper analysed the forms of heavy metals (Zn Pb Cd and As) of the Smelting Slag for Lead and Zinc,using BCR sequential extraction. Different chemical morphological of heavy metals have different activity and harmfulness. Migration and Utilization of heavy metals were decided by the existent form of heavy metals in the soil,which influenced Bioactivity and Toxicity. The results show that the main forms of Zn and Cd are Oxidizable and Residual fraction, and Pb mainly occurred in Oxidizable and Reducible fraction. however, As mainly occurred in Residual fraction, which the percentage of reachs 99.56%. According to the percentage of fractions extracted in total content (As is 0.44%, Zn is 14.7%, Pb is 85.98%, Cd is 48.86%),the latent ecological risk of heavy metals varied in the descending order of,Pb Cd Zn and As.
Cold Crystallization Behaviour of a Commercial Zr44-Ti11-Cu10-Ni10-Be25 Metal Glassy Alloy
Authors: Aversa Raffaella , Tamburrino Francesco , Parcesepe Daniela , Apicella Antonio
Published: February 2015

Isothermal crystallizations in the supercooled liquid metal metastable state at progressively increasing temperatures above the Glass Transition of the Zr44-Ti11-Cu10-Ni10-Be25 metal glass Alloy (cold crystallization attained by heating the samples from the glassy state) have been investigated in this study.Complex crystallization behaviours showing multiple exothermic peaks and selective crystallization of the alloy higher mobility atoms induced by the isothermal annealing, has been observed to lead to experimentally observed increase of the temperature needed to induce the glassy metal relaxation (glass transition). DSC dynamic investigation indicated that only two atomic species that are present in the metastable liquid are involved in recrystallization process below 450-470°C. Isothermal annealing in the range of temperatures between 400° and 450°C has been chosen for further investigation on thermal events kinetics occurring in the super-cooled liquid. The activation energies associated to the two crystallization processes are, respectively, -181 kJ/mol and-262 kJ/mol
Lab Scale Synthesis of Al-Sc Alloys in NaF-AlF3-Al2O3-Sc2O3 Melt
Authors: Zaikov Yuriy , Tkacheva Olga , Suzdaltsev Andrey , Kataev Alexander , Shtefanyuk Yuriy , Pingin Vitaliy , Vinogradov Dmitriy
Published: February 2015

The liquidus temperature in the [NaF-AlF3(30 mol.%)]-Sc2O3 molten system with the Sc2O3 additions up to 12 wt% was measured by the thermo analysis. The effect of the cathode current density (0, 0.25, 0.50, and 1.0 A∙cm-2), the Sc2O3 content (1, 2, 4, and 8 wt%) in the NaF-AlF3(30 mol.%)-Al2O3-Sc2O3 electrolyte, the rate of the molten aluminum agitation (0, 100 rotates/min), the synthesis duration (30-210 min) on the Sc content in the aluminum alloy at 980 °С was studied. The Al-Sc alloys with the scandium content of 0.15-1.30 wt%, depending on the synthesis conditions, and with the uniform Sc distribution throughout the aluminum matrix were produced.
The Compressive Behaviors of the Mg-Zn-Er Alloy Containing I-Phase
Authors: Liu Ke , Du Wen Bo , Wang Zhao Hui , Li Shu Bo
Published: February 2015

The microstructure and compressive behaviors of the Mg-Zn-Er alloy reinforced by I-phase were investigated. The XRD results suggested that the as-cast alloy was composed of -Mg and I-phase. During compress test, the deformation mechanism was depended on the test temperature and strain. It indicated that basal plane slip played an important role in deformation at both low and high temperature. However, the main deformation mechanism of the as-cast alloy includes grain boundary sliding and twins forming at the strain of 20% at a moderate temperature (225oC) besides the basal plane slip. Moreover, the DRX occurred at the moderate temperature after the strain of 50%. At high temperature (more than 300oC), the cavity was present, and the volume fraction of the cavities increases with the temperature increasing. At the high temperature, the deformation mechanism of the as-cast alloy is mainly dislocation sliding and climbing.
Multifunctional NaYF4:Yb3+, Er3+@Au Nanocomposites: Upconversion Luminescence, Temperature Sensing and Photothermal Therapy
Authors: Li Dong Dong , Shao Qi Yue , Dong Yan , Jiang Jian Qing
Published: February 2015

Composite nanostructures of NaYF4:Yb3+, Er3+@Au have been successfully prepared by attaching gold nanoparticles onto the surface of NaYF4: Yb3+, Er3+ upconversion nanoparticles (UCNPs). NaYF4 inert shell was used to adjust the separation distance between gold nanoparticles and UCNPs. Effects of the gold nanoparticles on their upconversion luminescent (UCL), temperature sensing and photothermal therapy properties were systematically investigated. For all samples, a slight decrease of the UCL intensity was observed after gold nanoparticles attachment, suggesting that the nonradiative quenching eﬀect is the dominant interaction between UCNPs and gold nanoparticles. However, the reduction of the UCL intensity is negligible due to the significant improvement of UCL properties by NaYF4shell. In addition, the gold attachment can obviously improve the photothermal conversion effect, but do not affect the temperature sensing properties of NaYF4:Yb3+, Er3+ UCNPs, indicating their high capability for multifunctional applications in biomedical fields.
Grain Refinement of High-Iron Aluminum Alloy by Inoculation with Al-B Master Alloy
Authors: Wang Yun Fei , Li Cheng Dong , Zhao Mei , Chen Di , Zhao Xiao Dong , Si Wen Qiang , Lin Ze Min , Yu Yue Hua , Liu You Mei , Qu Qi Yong
Published: February 2015

Aluminum cables are playing an increasingly important role in power transmission system, in which the “rare-earth high-iron aluminum alloy power cables were developed in China. In this paper, the effects of B on grain refinement of high-iron aluminum alloy were studied by using OM (optical microscopy), SEM (scanning electron microscopy), EDX (energy dispersive X-Ray spectroscopy) and XRD (X-ray diffraction). And the conductivity of high-iron aluminum alloy was also tested. The results showed that B could take significant effects on grain refinement and promote the increase of conductivity. The refinement may be mainly due to the eutectic reaction in solidification process and the formation of AlB2 particles. The optimal concentration of B was determined as 0.06 wt. %.
Interfacial Energy Anisotropy Affecting Dendrite Growth of Magnesium Alloy
Authors: Yuan Xun Feng , Yang Yan
Published: February 2015

Numerical simulations based on a new regularized phase field model were presented, simulating the solidification of magnesium alloy. The effects of weak and strong interfacial energy anisotropy on the dendrite growth are studied. The results indicate that with weak interfacial energy anisotropy, the entire dendrite displays six-fold symmetry and no secondary branch appeared. Under strong interfacial energy anisotropy conditions, corners form on both the main stem and the tips of the side branches of the dendrites, the entire facet dendrite displays six-fold symmetry. As the solidification time increases, the tip temperature and velocity of the dendrite and facet dendrite finally tend to stable values. The stable velocity of the facet dendrite is 0.4 at ε6 is 0.05 and this velocity is twice that observed (0.2) at ε6 is 0.005.
A New Al-ZnS Master Alloy Designed for Modifying Hypereutectic Al-Si Alloy and its Refinement Performance on Primary Si
Authors: Li Cheng Dong , Si Wen Qiang , Zhao Mei , Sun Chuan Hao , Guo Xiao Song
Published: February 2015

To increase the industrial applicability of hypereutectic Al-Si alloys, various methods have been used to refine primary silicon. The addition and refinement effects of phosphorus (P), rare earth metals (RE) on primary Si have been studied widely, But they have been testified be with some disadvantages, that is, the pollution to the environment of P and the high cost of RE, etc. Now, a new refiner - ZnS and the corresponding processing technology were researched. Microstructures of hypereutectic Al-Si alloy (Si wt. 24%) with fine primary Si were successfully obtained. And the primary Si can be refined from more than 80μm to 20μm. And the distribution of primary silicon is getting more uniform.
Electrolytic Aluminizing of Low-Carbon Steel in NaF-KF-AlF3 Melt
Authors: Zaikov Yuriy Pavlovich , Kovrov Vadim Anatolyevich , Brodova Irina , Shtefanyuk Yuriy , Pingin Vitaliy , Vinogradov Dmitriy
Published: February 2015

A multilayer intermetallic coating on low-carbon steel was obtained during aluminum electrodeposition in NaF-KF-AlF3 melt at 920 °C. The current density effect on morphology and intermetallic layer composition was investigated. Electrolytically aluminized steel samples represented a good oxidation resistance at 900 °C.
Influence of Solid-Liquid Composite Casting on Interface and Microstructure of High Chromium Cast Iron
Authors: Li Xiu Lan , Zhou Xin Jun , Xie Wen Ling , Ma You Ping
Published: February 2015

High chromium cast iron and stainless steel bimetal were fabricated by liquid-solid composite casting .The interface diffusion behavior and microstructure evolution of high chromium cast iron were studied. The results indicated that interface element diffusion behavior between stainless steel and high chromium cast iron was obviously existed. Under experimental conditions, there were many refined grainy-shaped carbides precipitation in stainless steel near interface, located at austenite grain boundary and intragranular austenite. As for high chromium cast iron, the morphology of the carbides varied from the interface to the specimen edge. The rod shaped carbides approached to composite interface were finer and become coarser rod-like or blade-like with increased distance from the composite interface. The reasons for elements diffusion and microstructure change were associated with alloys contents and temperature field.
The Effect of Forming Speed on the Formability of a Zr-Based Bulk Metallic Glass
Authors: Xiao Wu , Li Jian Jun , Zheng Zhi Zhen , Li Jin Yang
Published: February 2015

Taking cup-shaped part (outer diameter D and wall thickness are chosen as 2.2 mm and 0.05 mm, respectively) as an example, the micro-back-extrusion forming process of a Zr55Cu30 Al10Ni5 bulk metallic glass (BMG) in its supercooled liquid region was studied by using finite-element analysis (FEM) and experiment. The effect of forming speed on the formability was analyzed based on the extrusion load, the rheological behavior of the material and the microstructure of the formed parts. It was found that while the forming speed is below than 4 μm/s, the extrusion load increases obviously with the increasing in forming speed, otherwise, the BMG will follow non-newtonian flow and the forming load is insensitive to the forming speed. The parts fabricated at 2 μm/s are obviously crystallized due to the long retention time of metallic glasses at high temperature, a higher forming speed is benefit to enhancing the formability if the BMG. On this basis, micro cup-shaped parts with only 0.05 mm in wall thickness are successfully extruded.
Comparative Studies for the PAMAM/RE and HPAE/RE (RE=La, Nd, and Eu) Based on Molecular Dynamics Simulations
Authors: Li Sui Qin , Liu Yan Zhi , Lv Ling Ling , Zhu Yuan Cheng
Published: February 2015

Dendrimer used as template which can better control the size, shape and dispersion of the rare metal nanoparticles. In this paper, we comparatively studied the nanocomposites of the polyamidoamine dendrimer PAMAM/RE and hyperbranched poly (amine-ester) HPAE/RE (RE=La, Nd, and Eu) based on the molecular dynamics simulation method. It was theoretically discussed the feasibilities of the PAMAM and HPAE as templates, the results show that the system energies decreases and tends to be stable after the compositions of the template molecules PAMAM and HPAE with the rare metal atoms (La, Nd, and Eu). Among them, changes of bond stretching, bond angle bending energy and van der Waals play a key role to the potential changes. The radiuses of gyrations of the composite systems are all smaller than the corresponding template molecules. The molecular dynamic information obtained by using of molecular simulation can not only make a reasonable explanation for the macroscopic experimental phenomena, but also greatly promote the development and application of the dendrimers.