Effect Of Annealing Conditions Research Articles

Relationship between mechanical properties and microstructure in a 1.5% Mn–0.3% Mo ultra-low carbon steel with bake hardening

Effects of annealing conditions on the mechanical properties including bake hardening, microstructure, and texture were investigated in a 1.5% Mn–0.3% Mo ultra-low carbon steel. Bainitic ferrite with high dislocation density became predominant in the microstructure when both higher annealing temperature and higher cooling rate were combined. The highly dislocated phases transformed at low temperatures enhanced both bake hardening and anti-strain aging properties at room temperature, indicating the possibility for producing the non-aging bake-hardenable high strength steel. However, it is necessary to optimize the processing conditions to improve elongation because the highly dislocated structures deteriorated elongation significantly. It is suggested that the γ-fiber intensity can be strengthened through the control of ferrite volume fraction during annealing in the two-phase region.

Effect of annealing conditions on structural transformation of ZnS thin film

We’ve built this digital research platform to provide academics everywhere with fast, stable and secure digital access to our library of over 110,000 scholarly books and 800,000 journal articles. We’ve tested the platform in close cooperation with leading academic institutions. If you have any questions or you notice something doesn’t quite work as it should, please visit our <a href="/publishing/faq?lang=en" class="text-primary">Help/FAQ</a> page and let us know.

Industrial Cu-Ni alloys for HTS coated conductor tape

Copper rich Cu-Ni alloys have been textured with the RABiTS method in order to get non-magnetic and cost efficient substrates for coated conductor wires. The study is focused on two industrial compositions: Cu55Ni45 (Constantan) and Cu70Ni30. Studies on surface roughness have been done. The effects of annealing conditions (temperature and atmosphere) on the grain boundaries deepness were analyzed. Electrolytic polishing was also applied to improve the surface quality. RX pole figures and micro hardness measurements have been achieved on samples annealed up to 950°C. Attention has been paid to the rolling texture and to the annealing processes. The rolling texture has been found to be mainly copper-type (C, S and B contributions). Beginning of recrystallization occurred between 400°C and 600°C and stabilized between 900°C to 950°C, depending on the nickel content of the alloy. Finally both samples, rolled and annealed under the appropriate conditions, have been characterized. Pole figure measurements gave the global in plane and out of plane disorientations of our samples which are in-plane 7.4° and out-plane (RD) 4.3° for both samples. EBSD maps have shown the details of the distribution and have allowed us to quantify the ratio between cubic {100}<001> and twined {122}<21-2> orientations.

Effect of annealing conditions and concentration of oxygen vacancies on vanadium doped SrBi 2Ta 2O 9

This paper studied the annealing effects on the dielectric characteristics of vanadium doped SrBi 2Ta 2O 9 (SBT). SBT was synthesized at 1000 °C and vanadium doped SBT at 900 °C by solid-state reaction. Crystallization structure and phase purity of the prepared ceramic samples was observed by X-ray diffraction analysis. XRD analysis indicated a single layered perovskite structure without any secondary phases up to 15% of vanadium doping in SBT ceramics. Detailed dielectric study on vanadium doped SBT ceramics indicated that post-sinter annealing enhances the peak dielectric permittivity, which is attributed to the increased homogeneity in the system at atomic scale upon annealing. Annealing for larger time interval suppresses the permittivity growth beyond transition temperature which gives a direct evidence for the existence of lower valance state of vanadium (V +4) in as-sintered SBTV ceramics and also the permittivity growth is related to the oxygen ions or oxygen vacancies created during sintering. UV–Vis spectroscopy was also performed to confirm the lower valance state of the vanadium ions in the ceramics.

Effects of annealing conditions on photoelectrical properties ofBa1−xSrxNbyTi1−yO3 thin-film resistor

The optical characteristics of barium–strontium titanate–niobate(Ba1−xSrxNbyTi1−yO3) thin-film resistor are investigated and the effects of annealing gas and annealingtemperature on photoelectrical properties are studied. Experimental results show thatBa1−xSrxNbyTi1−yO3 thin films are highly sensitive not only to visible light, but also to ultraviolet light. As compared toN2-annealeddevices, O2-annealed devices have higher photosensitivity and lower dark current. Moreover, the photosensitivityof the O2-annealed devices is reduced for higher annealing temperature. Based on scanning electronmicroscope (SEM) study and grain-boundary theory, it can be concluded that400 °C inO2 is the optimal annealing condition, which can give a photosensitivity as high as 8400% tovisible light and 5500% to ultraviolet light.

Ultra Grain Refinement of Low C Steels by Accumulative Roll Bonding

Refinement of grain size is one of the biggest challenges to produce steels with improved combination of strength and toughness. Ultrafine structures are being produced world-wide on various materials, including low carbon steel, using different types of processes. However, the majority of these processes also exhibit severe limitations because they are generally restricted to small samples and are difficult to be implemented on an industrial scale. A promising technique for industrial implementation is the Accumulative Roll Bonding (ARB), a process able to supply large samples, even in the laboratory scale. In this paper, warm intense straining (ε = 4) by ARB was applied to a plain low-C steel in order to develop ultrafine grains, aiming at sizes around 1-2 μm, suitable to maintain an adequate combination of strength and ductility. The effect of annealing conditions on the evolution of the work-hardened microstructure and the bonding behaviour after each pass were investigated. Orientation Imaging Microscopy was used to investigate the microstructure and give a quantitative assessment of high angle and low angle boundaries. It is showed that the frequency of high angle grain boundaries increases with the strain but the misorientation distribution remained far from that typical of a recrystallised material.

Influence of Rapid Thermal Annealing on the Luminescence Properties of Nanoporous GaN Films

Nanoporous GaN films were prepared by UV-assisted electrochemical etching. It was observed that by employing rapid thermal annealing (RTA), optical properties of porous GaN films could be considerably improved. The nanoporous GaN films were subjected to RTA within the temperature range of 500-1100°C under nitrogen and oxygen ambient. The band-edge photoluminescence (PL) intensity from the porous GaN films showed a monotonic increase with the annealing temperature up to 1000°C in N 2 . However, the band-edge PL intensity showed a drastic reduction for the porous samples annealed under oxygen ambient. Besides this, investigation of the effects of annealing conditions on Eu-implanted nanoporous GaN in N 2 and O 2 ambient was also carried out. We have observed that annealing in N 2 significantly enhances the Eu-related red luminescence around 621 nm, which implies that annealing conditions could play an influential role for light extraction from nanostructured GaN surfaces.

Effects of annealing conditions on the electrical properties of Bi4-xNdxTi3O12 (x = 0.46) thin films processed at low temperature

Neodymium-substituted Bi4Ti3O12 (BNdT) thin films were prepared by a chemical solution deposition technique on platinum- coated silicon substrates. All of the samples were annealed at the relatively low temperature of 600 °C by a rapid thermal annealing process in different atmospheres, such as O2, air, and nitrogen, and vacuum. Irrespective of different annealing atmospheres, all of the BNdT thin films exhibit good ferroelectric properties, such as a saturated hysteresis loop, good fatigue endurance, and low leakage current density. A large remanent polarization (Pr) of ∼48 μC/cm2 with an electric field of 240 kV/cm was observed from the BNdT thin film annealed in O2 atmosphere. The BNdT thin films annealed in nitrogen and vacuum, at reduced oxygen partial pressures, exhibit smaller Pr than that annealed in oxygen. The difference of Pr of the BNdT thin films annealed in different atmospheres may originate from differences in the grain sizes and the number of oxygen vacancies.

The effect of annealing conditions on the crystallization of Er–Si–O formed by solid phase reaction

Er–Si–O crystal is one of the promising materials for Si-based opto-electronic devices. Crystallization of Er–Si–O is obtained by solid phase reaction of an amorphous preform which contains Er–O and Si–O bonds. However detailed crystallization mechanism is not clear. This study reports that the control of oxygen content of the sample in the annealing process for crystallization affects the fine arrangements of Er–Si–O crystals, resulting in three different types of XRD patterns and correspondingly different PL spectrum fine structures. The sol–gel method was used to prepare the amorphous preform. The samples were then annealed at 1250 °C in Ar for the solid phase growth of Er–Si–O crystals. The obtained Er–Si–O crystals showed, however, some different types of XRD patterns and the PL spectra. It was speculated that a slight amount of residual oxygen in the annealing furnace affected the Er–Si–O crystal structure. To study the effect of oxygen, during solid phase growth three processes were applied; putting a Si cap on the sample to reduce the influence of the atmosphere, additionally putting a carbon sheet as oxygen getter on the sample covered with a Si cap and no Si capping. Three kinds of XRD patterns, PL spectrum fine structures, PLE spectra and PL time decays were observed, depending on the three processes. These results indicate that the fine arrangements of Er–Si–O crystals are affected by oxygen content in the crystal which is very sensitive to oxygen in the annealing Ar atmosphere during the solid phase growth and their properties are come from their particular crystalline structures.

Tin selenide synthesized by a chemical route: the effect of the annealing conditions in the obtained phase

The effects of different annealing conditions over the tin selenide obtained from a chemical route are presented in this work. The tin selenide was annealed at 300 and 600 °C under hydrogen, nitrogen and argon atmospheres. The materials were characterized by X-ray diffraction and 119Sn Mössbauer spectroscopy. In the ‘as synthetized’ material a considerably amount of tin oxide (57%) was detected by Mössbauer spectroscopy. After thermal annealing the amount of these oxides varied according to the temperature and atmosphere used. At 600 °C/hydrogen the smallest amount of tin oxide was obtained (20%). These oxides were formed during the synthetic procedure through the hydrolysis of tin chloride used as reagent.

An optical chemical sensor based on functional polymer films for controlling sulfur dioxide in the air of the working area: Acrylonitrile and alkyl methacrylate copolymers with brilliant green styrene sulfonate

The effects of the chemical and phase composition of acrylonitrile and alkyl methacrylate (Alkyl-MA) copolymers with styrene sulfonates (SS) of triphenylmethane dye cations on the gas permeability and sensing properties of their films were studied for developing an optical chemical sensor (OCS) for sulfur dioxide (SO2) on the basis of functional polymers. Of the three triphenylmethane dyes tested, namely, fuchsine, Crystal Violet, and Brilliant Green (BG), only the last dye was selected for molecular design. It was shown that the copolymer of Decyl-MA with SS—BG with the degree of modification DM = 0.10 is the best material among the studied ones from the viewpoints of sensitivity, response time, and time stability of sensor characteristics. The conditions for fabricating polymer films and the parameters of their functioning in OCSs for SO2 were optimized. The effect of annealing conditions on the sensitivity of spectra to SO2 was studied. Working temperature, working wavelength, and the conditions for the regeneration of the initial spectral parameters were optimized. Calibration characteristics of OCSs for the dynamic admittance of SO2—air mixtures were obtained. The calculated detection limit for SO2 in an air flow for a sensor with a sensing film fabricated of the decyl-MA—SS—BG copolymer with DM = 0.10 was 0.16 vol %, or 4160 mg/m3. This points to the necessity of searching for more sensitive sensing materials among other classes of functional polymers.

Molybdenum doped Indium Oxide thin films prepared by rf sputtering

AbstractMolybdenum doped indium oxide (IMO) thin films rf sputtered at room temperature were studied as a function of oxygen volume percentage (O2 vol. %) varied between 0 and 17.5. The as-deposited films were amorphous irrespective of O2 vol. %. The minimum transmittance (&lt;10 %) of the films deposited without oxygen has been increased on introducing oxygen (3.5 O2 vol. %) to a maximum of 90 %. The optical band gap has been increased from 3.80 eV (without oxygen) to 3.92 eV (3.5 O2 vol. %). The films were highly resistive and the hall coefficients were detectable only for the films deposited without oxygen. In order to increase the electrical conductivity, the films were annealed in the range 100-500°C in open-air and N2/H2 gas for 1 hour. The annealed films become polycrystalline with enhanced electrical and optical properties. The effect of annealing conditions on these films will be presented and discussed in detail.

Enhancement of adhesion strength of Cu seed layer with different thickness in Cu∕low-k multilevel interconnects

A systematic study was made on the properties of a copper (Cu) seed layer deposited with two different thicknesses and subsequent annealing to enhance the adhesion strength to avoid peeling and delamination in Cu∕low-dielectric constant (k) multilevel interconnects. Though the effects of annealing conditions have been much studied in the past, less is known about the relation between thermal stability of copper seeds at low and high annealing temperatures of 100 and 300°C, respectively, with seed thickness below 1000Å. Adhesion strength of copper seeds annealed at 100, 200, and 300°C in N2 ambient for 30min was carried out to study the impact on adhesion strength and the microstructure evolution of coupling effect of thin copper seed layers and low annealing temperatures. The lowest observed resistivity was 1.96μΩcm in the 1500Å Cu seed annealed at 300°C, which reduced from 2.10μΩcm in as-deposited condition. In the study, we found that minimal agglomeration of the Cu seed layer and stronger bonding at the Ta∕Cu interface indicates higher reliability for copper damascene structure. This further strengthens our claim that a lower annealing temperature is essential for enhancing adhesion strength and interfacial bonding between Cu∕dielectric.

Effects of annealing conditions on humidity-sensing characteristics of SrNbxTi1−xO3 thin-film resistor on SiO2/Si substrate

Abstract Strontium titanate–niobate (SrNb x Ti 1− x O 3 ) film deposited on SiO 2 /Si substrate by argon ion-beam sputtering technique is used to fabricate thin-film resistors by standard integrated-circuit technology. Effects of annealing conditions on their humidity-sensing characteristics were studied. Four cases were considered: 400 °C 20 min in N 2 ; 400 °C 20 min, 400 °C 4 h and 600 °C 4 h in O 2 . Experimental results showed that, as compared to the N 2 -annealed device, the O 2 -annealed devices have higher humidity sensitivity and faster response. Based on scanning electron microscope (SEM) study and adsorption-isotherm analysis, it can be concluded that oxygen annealing is helpful for grain growth, thus resulting in a higher porosity of the film. Among the four cases, 400 °C 4 h in O 2 is the best annealing condition, which gives rise to the highest porosity and an appropriate pore-volume distribution for improving the humidity sensitivity.

Effect of Different Annealing Condition on Bake Hardenability for Environmental Automotive Panel

Bake hardenability steel sheets are used increasingly more for automotive outer panels, because they exhibit high yield strength after painting the baking treatment while they have a good formability in the press stamping stage. Bake hardening utilizes the phenomenon of strain aging to provide an increase in the yield strength of formed components. So high carbon solubility levels increase the bake hardening response but reduce the room temperature aging resistance. This study is on the effect of annealing conditions such as soaking temperature, rapid cooling start temperature, cooling rate on BH(Bake hardenability), AI(Aging Index), YP-El(Yield point Elongation) and other mechanical properties.

MgO substrate surface optimization for YBaCuO thin film growth

To obtain high quality Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/ (YBaCuO) films grown on [001] MgO substrates, we have investigated the influence of high temperature substrate annealing prior to film deposition. In particular, we discuss the effect of annealing conditions (atmosphere, temperature and time) on MgO substrate morphology observed with atomic force microscopy. Thermal treatment under specific conditions resulted in the formation of [001]-oriented terraces bounded by [100]-oriented steps on the substrate surface. An improvement in the crystalline quality, as well as better DC electrical properties and microwave surface resistance values, has been observed for films sputtered onto substrate surfaces exhibiting such regular nanoscale step structures.

Effects of annealing conditions on charge storage of Si nanocrystal memory devices obtained by low-energy ion beam synthesis

The structural and electrical characteristics of thin silicon dioxide layers with embedded Si nanocrystals are reported fabricated by low-energy silicon implantation and with subsequent annealing in inert and diluted oxygen. Thermal treatment in diluted oxygen increases the thickness of the control oxide, does not affect significantly the size of the nanocrystals, and improves the integrity of the oxide. As a result, strong charge storage effects at low gate voltages and enhanced charge retention times are observed through electrical measurements of MOS capacitors. These results indicate that a combination of low-energy silicon implants and annealing in diluted oxygen permits the fabrication of low-voltage nonvolatile memory devices.

The effect of annealing conditions on the red photoluminescence of nanocrystalline Si/SiO 2 films

Nanocrystalline Si (nc-Si) embedded in a SiO 2 matrix, fabricated by plasma CVD and a subsequent post-treatment shows a broad red photoluminescence (PL). In this paper, the effects of annealing temperature, atmosphere and time on the red PL from 1.75 to 1.5 eV have been investigated in detail. It is found that the spectral shift and the PL intensity from 1.75 to 1.5 eV show a strong and unique dependence on annealing conditions. For a PL approximately 1.75 eV, upon 400 °C forming gas annealing, the spectral shift and the peak intensity versus accumulation annealing times show a novel temporal oscillation. This unique dependence and the novel temporal oscillation behavior, which have not been reported in porous silicon, exclude nc-Si itself as the source of the red PL. Instead they favor oxygen thermal donors (TDs)-like defect states as PL centers. This is in consensus with our earlier results of defect studies using electron spin resonance in this system. Furthermore, two PL centers in this red PL were distinguished according to their variance in annealing temperature- and time-dependence. The spectral change between 1.5 and 1.75 eV upon annealing conditions can be qualitatively explained by using the formation and annihilation kinetics of two oxygen TDs-like defect state.

The effects of deposition and annealing conditions on crystallographic properties of sputtered barium ferrite thick films

Abstract The development of devices combining a ferrite with a semiconductor chip is a major focus of current research and could make use of vacuum deposition techniques of magnetic films. Barium hexaferrite (BaFe12O19; BaM) thick films are deposited here using an rf non-reactive sputtering system. Because the as-deposited films are amorphous and non-magnetic, two kinds of post-deposition annealing are employed, which are referred to here as classic thermal annealing (CTA) and rapid thermal annealing (RTA). The effects of annealing conditions on the properties of BaM films are studied using vibrating sample magnetometry (VSM), scanning electron microscopy (SEM) with an EDX probe and X-ray diffractometry (XRD). The first results show a good stoichiometry of the layer and a crystallization above 800 °C. The magnetic properties are closed to that of the bulk BaM. Progress is still necessary to obtain a temperature more compatible with microelectronic technologies (below 500 °C).

Fundamental studies on large area Cu(In,Ga)Se 2 films for high efficiency solar cells

This work reports the growth and characterization of thin films of Cu(In,Ga)Se 2 (CIGS), which were grown by sequential sputtering, electrodeposition, and physical vapor deposition. Photovoltaic cells have been fabricated using these films with CdS heterojunction partners and the performance has been characterized. The effect of annealing conditions (temperature and duration) on the CIGS film microstructure and corresponding device performance has been investigated. Structure-property correlations were made using diffraction studies and Rietveld analysis. SEM studies were carried out to understand the effect of microstructure of the CIGS films on the solar cell efficiency. Cell efficiencies in excess of 10% have been achieved by using optimized annealing conditions. In addition, the optical properties of the sputtered CIGS films were characterized using variable angle spectroscopic ellipsometry and sputtered CIGS films were found to have optimum band gap.