The Influence of Annealing Temperature and Soaking Time on the Ductility of SG 255

This study deals with the effect of annealing temperature on the mechanical properties of SG 255 steel. Furthermore it aims to experimentally obtain better mechanical properties in particular ductility with lower annealing temperature and to minimize the cost of the manufacturing. The SG 255 steel is used in manufacturing of domestic LPG cylinder at Halala Company located in Sulaimanyah/Iraq. A number of samples were made according to ISO 6892, and then heat treated with different annealing temperature (850, 900 and 950 ºC). Moreover, the mentioned samples were broken by tensile machine to obtain the required mechanical properties, and to be compared with that of Halala factory. It was shown that higher elongation percentage 34.18%El with lower annealing temperature 900 ºC can be achieved and this leads to decrease the cost of manufacturing without degrading of cylinder’s quality.

Annealing Temperature Effect on Creep Property of CZ Alloy for PWR Modern Fuel Claddings

Zirconium alloys remain as the main cladding materials in most water reactors. CZ zirconium alloy is recently developed for advanced PWR fuel assembly (STEP) designed by China General Nuclear Power Group (CGN). There are two kinds of zirconium alloys, designated as CZ1 and CZ2 respectively. It is well known that creep property is one of the most important characteristics to evaluate the integrated performance of new commercial alloys. In this study, we have collected the creep date of CZ alloys heat-treated at different temperatures. The result shows that the creep rates of the zirconium alloys enlarge with the creep stress in the temperature of 375 °C. The creep resistance is improved with the increasing annealing temperature. The creep resistance of CZ-RXA (high temperature) is better than CZ-SRA (low temperature). The creep rate of CZ alloys at relatively lower annealing temperature is much larger than that at higher annealing temperature. At the given stress condition, the creep behaviors of different annealed CZ alloys are found to have almost the same tendency. In addition, the creep rate of CZ1 is smaller than CZ2 at the same annealing temperature.

Al+ Ion Implanted 4H-SiC Vertical p+-i-n Diodes: Processing Dependence of Leakage Currents and OCVD Carrier Lifetimes

The reverse and forward currents of Al+ ion implanted 4H-SiC p+-i-n diodes have been compared for identically processed devices except for the implanted Al concentration in the emitter, 6×1019 cm-3 against 2×1020 cm-3, and the post implantation annealing treatment, 1600°C/30 min and 1650°C/25 min against 1950°C/5min. The diodes’ ambipolar carrier lifetime, as obtained by open circuit voltage decay measurements, has been compared too. The devices with lower annealing temperature show lower leakage currents and higher ambipolar carrier lifetime; they also show lower current in ohmic conduction.

Evolution of the Helium-Related Defect in Polycrystalline Tungsten

The evolution of the helium-related defect in polycrystalline tungsten was studied by Doppler Broadening Positron Annihilation Spectroscopy and Scanning Electron Microscope as functions of annealing temperature and implantation fluence. The experimental results showed that the defect type was not changed at lower annealing temperature, and the decline of S parameter manifested that the lower temperature annealing led the decrease of defect concentration. In addition there existed the same defect type with the increment of the implantation fluence, thus the rise of S parameter implied the increase of the defect concentration.

Synthesis and Characterization of Nanocrystalline Barium–Samarium Titanate

Barium–samarium titanate nanopowder (Ba0.85 Sm0.1TiO3) was synthesized through tartrate precursor route. The effect of annealing temperature on the formation, crystalline size, morphology and magnetic properties was systematically studied. The annealing temperature was varied from 600°C to 1,100°C. Thermal analysis measurement (TG-DSC, thermogravimetry-differential scanning calorimetry) was carried out on the precursor to characterize the thermal decomposition behavior. The results showed that the precursor of Ba–Sm–Ti mixture decomposed thermally in multistep weight loss up to about 480°C and perovskite Ba0.85Sm0.1TiO3 started to form at ~520°C. X-ray diffraction and Fourier transform infrared (FTIR) spectroscopic measurements showed that the synthesized Ba0.85Sm0.1TiO3 has a tetragonal dominant structure with the presence of intermediate SmTi2O3 at lower annealing temperature. The ratio of SmTi2O3 was decreased and completely disappeared at higher annealing temperatures. The tetragonality, the theoretical density and the crystalline size were increased by increasing annealing temperature. The crystalline size is still in nano-range of 12.4–19.9 nm even after annealing at 1,100°C. The morphology of the produced sample transferred from nano-cubes to nano-whisker to nano-mace (nano-aggregates) with the increase of annealing temperature.

Low-Temperature Production of Genuinely Amorphous Carbon from Highly Reactive Nanoacetylide Precursors

Copper acetylide is a well-known explosive compound. However, when the size of it crystals is reduced to the nanoscale, its explosive nature is lost, owing to a much lower thermal conductance that inhibits explosive chain reactions. This less explosive character can be exploited for the production of new carbon materials. Generally, amorphous carbon is prepared by carbonization of organic compounds exposed to high temperature, which can induce partial crystallization in graphite. In this work, we present a new method in which the carbonization reaction can proceed at a lower annealing temperature (under 150°C) owing to the highly reactive nature of copper acetylide, thus avoiding crystallization processes and enabling the production of genuinely amorphous carbon materials.

Microstructural and Electrochemical Properties of LiCoO2 Thin Films Prepared by Metal-Induced Crystallization

LiCoO2 thin films were fabricated using the metal-induced crystallization (MIC) method. The effect of MIC on the microstructural and electrochemical properties of the films was investigated. The crystal structures and surface morphologies of the deposited films were investigated by X-ray diffraction (XRD), Raman spectroscopy, and field emission electron microscopy (FE-SEM). Charge–discharge tests were carried out in order to examine the electrochemical properties of the films. The LiCoO2 thin film fabricated using MIC exhibited better microstructural and electrochemical properties at a lower annealing temperature.

EFFECT OF ANNEALING TEMPERATURE ON STRUCTURAL AND OPTICAL PARAMETERS OF SOL–GEL ROUTED MOLYBDENUM OXIDE THIN FILM

The influence of annealing temperature on structural and optical properties of sol–gel routed spin-coated molybdenum tri oxide ( MoO 3) thin films are studied. The higher annealing temperatures improve the crystalline nature of the film. The X-ray diffraction (XRD) study reveals the formation of α-orthorhombic phase at higher annealing temperature and amorphous nature at lower annealing temperature. The optical bandgap of molybdenum tri oxide ( MoO 3) film is found to be 3.3–3.8 eV, and the refractive index of the film is found to be 2.2–2.9. The dispersion curve of the refractive index shows that an abnormal dispersion in the absorption region and normal dispersion in the transparent region are observed. The optical polarizability, optical conductivity, dielectric constant, volume and surface energy loss parameters are evaluated.

Crystallization and Reconstructive Layer Transformation of a-Si/Au Multilayer Thin Films under a Strong Gravitational Field

There were still unclear questions in the new method that fabricate the high quality poly crystalline Si thin film from amorphous Si thin film with lower annealing temperature than conventional Si recrystallization temperature. In that recrystallization process, the recrystallization mechanism was generally explained by the MIC (Metal Induced Crystallization) of Au. In this paper, we have discussed the effects of film structure and strong gravity on recrystallization, by using conventional furnace and high-temperature ultracentrifuge furnace system. The five kinds of samples (two bilayered Si/Au thin films, two multilayered Si/Au thin films and trilayered Si/Au/Si thin film) and found the effects of structure and strong gravity. The best for crystallization was Au/Si multilayered thin film, which is almost finished to crystallize even at 673 K annealing. The strong gravity advanced and retreated the crystallization, depending to thin film structure.