Effect Of Annealing Treatment Research Articles

Stereometric and scaling law analysis of surface morphology of stainless steel type AISI 304 coated with Mn: a conventional and fractal evaluation

The purpose of this study is to determine the micromorphology of stainless steel type AISI 304 coated with thin films of Manganese post-annealed by the flow of nitrogen at different annealing temperatures using atomic force microscopy (AFM) and fractal/multifractal analyses. The coated samples were annealed with a nitrogen flow of 400 sccm at four different temperatures of I group, 473 K; II group, 623 K; III group, 773 K; and IV group, 923 K. AFM was used to image the 3D surface micromorphology in tapping mode, on square areas of 2 × 2 μm2. The approaches in both measurement and data analysis when using AFM analysis and surface fractal/multifractal analyses are essential for the correct interpretation of 3D surface topographic features and offer the 3D surface texture parameters and surface fractal dimension. The more irregular surface (Sq = 22.23 nm) was found in IV group, and the more regular surface (Sq = 5.86 nm) was found in II group. The result shows the effect of annealing treatment on fractal/multifractal characteristics of surfaces.

Optimizing the electromagnetic properties of the FeCoNiAlCrx high entropy alloy powders by composition adjustment and annealing treatment

High entropy alloy powders are promising candidates for new microwave absorbents due to its advantages in corrosion resistance, heat resistance and soft magnetic properties. In this work, flake-shaped FeCoNiAlCrx (x = 0.1, 0.3, 0.5, 0.7, and 0.9, in molar ratios) alloy powders are prepared by mechanical alloying, and then annealed at 500 °C. The experimental results show that the milled and annealed FeCoNiAlCrx powders contain similar FCC and BCC phase structure. The addition of Cr element results in more flattened powder particles and more polarization sites, which enhances the surface polarization and ultimately increases the real and imaginary parts of complex permittivity (ε′ and ε″). The real and imaginary parts of complex permeability (μ′ and μ″) decrease first and then increase as the proportion of Cr increases. The minimum reflection loss (RLmin) is improved and moves to the low frequency region (11.20 GHz to 8.23 GHz) as the proportion of Cr increases. After annealing, the enhanced saturation magnetization (Ms) increased μr, and the improvement of crystallinity also increased εr. For FeCoNiAlCr0.9 samples, annealing treatment directly improves the minimum reflection loss from −26.88 dB (8.23 GHz) to −47.55 dB (7.375 GHz), suggesting the positive effects of annealing treatment on reflection loss. All the above findings provide experimental and theoretical basis for FeCoNiAlCrx high entropy alloy powders as absorbing material.

Effect of annealing treatment on PVDF nanofibers for mechanical energy harvesting applications

Piezoelectric nanofibrous films with superior flexibility have attracted the emerging applications including sensors and actuators, piezoelectric nanogenerators (PNG) and energy storage devices. Herein, polyvinylidene fluoride (PVDF) piezoelectric nanofibrous film have been made by the electrospinning technique and been exposed to annealing as a post processing treatment at 40, 70, 100 and 130 °C for 4 h in air-flow oven. Four kinds of samples annealed at various temperatures have been pointed out as PVDF40, PVDF70, PVDF100 and PVDF130, respectively. The crystalline phases and thermal responses of the annealed film have been examined with XRD, FTIR and DSC. Also, mechanical and electroactive investigations exhibited that annealing treatment has effectively enhanced the dielectric constant, piezoelectric coefficient and the polar β-phase. Moreover, the annealed PVDF film acts as an effective layer of the PNG with enhanced crystalline structure and polar β-phase fraction. When the film is annealed at 100 °C, the voltage output of the PNG can attain maximum microstrain of 1000 με. The developed PVDF100 nanofibrous film-based PNG can generate output voltage of 0.516 V and 0.505 V with a tensile and compressive microstrain measured using the microstrain indicator of 1000 με. It shows better results compared to PVDF40 of 0.221 V. The enhanced voltage output of the PNG is recognised to be the collaborative involvement of the electrospinning and annealing treatment which could improve the piezoelectric response of the annealed film. This work presents that the annealed PVDF nanofibrous film based highly compliant PNG could be a promising candidate for flexible self-powered electronic applications.

Microstructures and properties of TiCp/Al coating synthesized on Ti–6Al–4V alloy substrate using mechanical alloying method

A TiCp/Al coating was synthesized on the Ti–6Al–4V alloy substrate by mechanical alloying method. The microstructure, the mircohardeness, the friction and wear resistance and the high-temperature oxidation resistance of the coating, as well as the effect of annealing treatment on them were investigated. The results showed that the coating had a TiC particles reinforced Al matrix composite structure in which the reinforcing particles were uniformly dispersed in the matrix. The microhardness, the wear resistance and the oxidation resistance were improved because of the as-synthesized coating. After annealing treatment, the coating formed a bi-layer structure, including an outer TiCp/Al composite layer and an inner Al3Ti layer. The outer layer had low microhardness and tended to be flaked in both friction and oxidation processes. The inner layer showed more than 5 times of microhardness values of the outer layer and had favorable wear resistance. But during long-time oxidation process, the inner layer had a stronger tendency of forming microdefects compared with the unannealed coating. In general, the TiCp/Al composite coating could protect the substrate from being severe worn or oxidized. The annealing treatment to the coating was conductive to the further improvement of its microhardness and wear resistance, but had limited effects on its oxidation resistance.

Effect of annealing treatment on the structure and performance of transparent conductive AZO/Al2O3 bi-layer films

Transparent and conductive Al-doped zinc oxide (AZO) films have a wider band gap, good optoelectronic characteristics, inexpensive and nontoxicity, compared with indium tin oxide (ITO). In this study, AZO films are deposited onto Al2O3/glass using magnetron sputtering. After deposition, both conventional annealing (CA) and rapid thermal annealing (RTA) are used to obtain a high quality AZO/Al2O3/glass bi-layer. The XRD and TEM images show that the film has a poly-crystalline nature with a hexagonal wurtzite-type structure. As the annealing temperature is increased, the intensity of the (0 0 2) diffraction peak increases and there is decrease in the full width at half maximum, which indicates that the films undergo a thermally activated process of grain growth and exhibit improved crystallization. RTA produces a larger grain, a greater carrier concentration and better crystallinity than CA. After RTA at 500 °C, the AZO/Al2O3 bi-layer films result in the lowest electrical resistivity, the highest optical transmittance and a good figure of merit. The bi-layer films are subject to a pull-off adhesion strength test, which shows that have a superior peel off stress. The experimental results show that these AZO/Al2O3 bi-layer films have good optoelectronic performance and adhesive strength.

The effect of annealing treatment on the evolution of the microstructure, the mechanical properties and the texture of nano SiC reinforced aluminium matrix alloys with ultrafine grained structure

In the present work, an ultrafine grained (UFG) aluminium matrix nano composite (UFANC) was prepared through a cryogenic deformation based manufacturing route. The influence of annealing on the microstructural evolution, mechanical properties and the crystallographic texture of the developed UFANC material was studied and compared with the unreinforced ultrafine grained counterpart (UFG). The presence of nano particles during deformation led to an increased generation of dislocations in the matrix. At low annealing temperatures high density dislocations provided a higher driving force for recrystallization in the UFANC. At high temperatures the grain growth in the UFANC was restricted by the pinning action of the nano reinforcement. This resulted in a higher activation energy for grain growth compared to the UFG counterpart. As a result, the UFANC retained high strength and possessed a fine microstructure even at annealing temperatures of up to 250 °C. The evolution of the texture during annealing was influenced due to the deformation at cryogenic environment. The presence of nano particles led to a more random texture in the UFANC compared to the UFG counterpart during annealing.

Estimation of mass transfer rate and primary drying times during freeze-drying of frozen maltodextrin solutions based on x-ray μ-computed tomography measurements of pore size distributions

The study presents a method to estimate the mass transfer rate during primary drying based on μ-computed tomographic measurements of a freeze-dried cake. The study was carried out in a defined setup in a lyomicroscope and confined geometry in which freezing occurred under homogeneous nucleation, and drying under mass-transfer-limited conditions. Pore size distribution, effective diffusivity, and primary drying rates of maltodextrin solutions at different weight concentrations (5%, 10%, and 20% (w/w)) and different cooling rates were determined. Furthermore, the effect of annealing treatment on primary drying rate was studied. Two different annealing treatments were tested, one for 90 min at −10 °C and another for 180 min at −5 °C. It was shown that solid concentration and annealing above Tg’ have the strongest impact on pore size and, subsequently, on primary drying rate. Therefore annealing represents a powerful tool to accelerate primary drying which is the most time-consuming step during lyophilisation.

The Effect of Annealing on Microstructure and Mechanical Properties of Selective Laser Melting AlSi10Mg

The effect of annealing treatment on SLM AlSilOMg on microstructure and mechanical properties has been investigated. It is observed that, with the increase of the temperature, the melt pools gradually become blurred and completely disappear when the temperature rises to 320°C. The microhardness and strengths of as-built samples are the highest due to the solid solution strengthening together with grain refinement strengthening. After heat treatment, the microhardness and strengths all decrease due to the weakening of solid solution strengthening but the elongation increases.

One-step methylammonium lead bromide films: Effect of annealing treatment

With the rapid increase of efficiency up to 23% during the past few years, hybrid organic-inorganic metal halide perovskite solar cells (PSCs) have become a research “hot spot” for many solar cell researchers. Hybrid perovskite structures have been obtained from methylammonuim lead bromide solutions deposited by one step spin coating deposition method. In this work, the effects of annealing temperature of the MAPbBr3 films and devices have been investigated in details. By tuning the variation of the temperature, the properties including photoluminescence, crystallinity and morphology of perovskite films together with device performance have been affected significantly by the annealing temperature. The devices annealed with 70 °C shows the best device performance and exhibit a maximum Fill Factor around 76.5 and a maximum efficiency at 2.89%.

Effect of annealing treatment on the dry sliding wear behavior of copper

The effect of annealing on the wear behavior of commercial grade pure copper (Cu) was evaluated by performing unlubricated pin-on-disc wear tests of as–received and annealed samples under 0.1–10 kgf normal load. It was found that annealing at 800 °C for 24 h led to an increase of grain size of Cu from ~ 6.7 to ~ 15.3 µm and a decrease in hardness. Wear rates of both samples increased while the friction coefficients decreased with increasing normal load. Subsurface microstructure evolution and wear debris were characterized by high resolution electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) after wear tests. Dynamic recrystallization and abnormal subsurface grain growth were observed in both samples under high load. Finally, the effect of annealing on the microstructure evolution and wear resistance of Cu were discussed.

Effect of Annealing Treatment on Mechanical and Magnetic Softening Behaviors of Cold Rolled Interstitial-Free Steel

The recovery and recrystallization behaviors of low-carbon interstitial-free steel are investigated at different annealing temperatures (200-690 °C) through correlation between the changes in magnetic parameters (coercivity and r.m.s. voltage), hardness, tensile strength and high-angle grain boundary fractions (HAB). Magnetic parameters and tensile strength show a significant change within recovery region (200-500 °C), while the hardness variation is very minimal at this temperature region. On the other hand, the hardness is abruptly changed compared to magnetic properties at higher annealing temperature (550-640 °C). The grain boundary characteristics and microtexture evolution occurring at recrystallization regime are evaluated by orientation imaging microscopy (OIM) and orientation distribution function (ODF) through electron backscattered diffraction (EBSD). The increase in recrystallization fraction noticeably affects microtexture property, justifying with the strengthening of γ-fiber, weakening of α-fiber and disappearance of rotated cube component with increasing annealing temperatures.

Colossal dielectric behavior of Co-doped TiO2 ceramics: A comparative study

The (Nb + In) co-doped rutile TiO2 ceramics were synthesized by spark plasma sintering (SPS) and traditional solid-state sintering (TS) techniques, respectively. Highly-density co-doped rutile TiO2 ceramics are prepared with the SPS method by 20 min, whereas it takes nearly 30 h with the TS method. It is observed that SPS ceramics showed smaller and uniform grain size, and better densification than TS counterparts. Both sets of the co-doped TiO2 ceramics showed single rutile phase according to X-ray diffraction (XRD) results. X-ray photoelectron spectroscopy (XPS) is adopted to detect and compare the element-valence-state of both sets of the co-doped TiO2 ceramics. The dielectric response, impedance spectroscopy (IS), and the effects of annealing treatment are systematically investigated, which could not only be helpful for optimizing their dielectric properties, but also shed the light on the colossal dielectric mechanism.

The promotion of Indeno [1, 2-b] flourene-6, 12 dione thin film to be changed into stable aromatic compound under the effect of annealing treatment

Thin films of Indeno [1, 2-b] flourene-6,12-dione (I[1, 2-b]F dione) were performed by the thermal vacuum evaporation technique. The identifications of a thin film such as structure, molecular structure and surface morphological were determined before and after annealing temperature using Fourier-transform infrared (FTIR), X-Ray diffreaction (XRD) and Scan electron microscopy (SEM). FTIR spectrum showed a diminishing of C═O bonds after annealing treatment. The analysis of XRD clarified that I[1, 2-b]F dione in its powder form is orthorhombic with space group P222. On the other hand, the as-deposited thin films were realized by amorphous nature, while the annealed I[1, 2-b]F dione thin films showed polycrystalline nature. The calculation of the average crystallite sizes proved that the annealed I[1, 2-b]F dione thin films were characterized by their nanostructure property. The SEM images illustrated that the aggregation of the particles has the formation of the nano-rod shape associated with average width in the range of 120–150 nm for the as-deposited thin film, while the average width of the branched nano-rod shape for the annealed thin films was observed to be in the range of 150–200 nm. The transmittance and reflectance spectrum at normal incidence of light in the range 190–2500 nm were employed to discuss the optical properties of as-deposited and the annealed I[1, 2-b]F dione thin films. Our conceptions elucidated that the optical transition type of I[1, 2-b]F dione films is the indirect allowed transition. The values of the fundamental energy gap for the as-deposited and the annealed films at 473 K were calculated out be 3.41 and 3.70 eV respectively. The dispersion of the refractive index was studied according to the single oscillator model. Moreover, the third-order nonlinear susceptibility and the nonlinear refractive index for I[1, 2-b]F dione thin films were calculated.

Effect of annealing and chemical treatment on structural and optical properties of CuPcTs/PEDOT:PSS (BHJ Blend) thin films

In this work, The effect of annealing treatment at different temperatures (373, 423 and 473) K and chemical treatment with talwen at different immersion time (40, 60 and 80) min on structural and optical properties of the bulk heterojunction (BHJ) blend copper phthalocyanine tetrasulfonic acid tetrasodium salt/poly dioxyethylenethienylene doped with polystyrenesulphonic acid (CuPcTs/PEDOT:PSS) thin films were investigated. The films were fabricated using spin coating technique. X-ray diffraction (XRD) measurements displayed only one peak at 2θ =4.5o corresponding to (001) direction which has dhkl larger than for standard CuPcTs. The dhkl increase then decrease with increasing annealing temperature andthe time of chemical treatment with talwen. FTIR measurements show that, the peaks for O-H, in general, decrease with increasing annealing temperature, while the peaks corresponding to C=C aromatic bond and C-N bond decrease at 373 K then increase at 423 and 473 K. The peaks for O-H, in general, decrease with increasing immersing time, while the peaks corresponding to C=C aromatic bond and C-N bond decrease at 40 min then increase at more immersing time. From UV-visible measurements, the absorption spectra peaks for B and Q-bands increase at 373K and at 40 min immersing time with talwen and decrease at more annealing or chemical treated time.

Effect of Annealing Treatment on Microstructure, Mechanical and Damping Properties of Ductile Iron

Ductile iron was prepared through Sandwich Process and annealing treatment was carried out. The effects of annealing treatment on the microstructure, mechanical and damping properties of ductile iron were studied by means of metallographic microscope, scanning electron microscope, transmission electron microscope, universal test machine and dynamic thermal mechanical analyzer. The results show that annealing treatment has little effect on the morphology and distribution of graphite cast iron, but it will lead to the decrease of pearlite content in the matrix, the increase of ferrite content and the disappearance of cementite. Annealing transforms the fracture form of ductile iron from cleavage fracture to quasi-cleavage fracture, which greatly increases the ductile fracture area of the matrix compared with the as-cast, and tends to develop ductile fracture. The annealing treatment results in a decrease in the tensile strength of the ductile iron, but it can increase the plasticity and increase the elongation after fracture to 7.5 times that of the as-cast state. The damping value of as-cast ductile iron increases first and then decreases with the increase of temperature, and peaks at 190 °C when Q-1 is 0.025. The damping value of annealing ductile iron decreases with increasing temperature. The damping value increases with increasing strain amplitude before and after annealing. Annealing treatment will reduce the sensitivity of the damping property of ductile iron to strain amplitude.

Effects of annealing treatment on mechanical properties of 8011 aluminum alloy after cryogenic rolling

In order to improve mechanical properties of roll cast 8011 aluminum alloy (AA 8011) by grain strengthening, and expand its application field, the effect of different annealing treating processes on mechanical properties and microstructures of cryogenic rolled AA 8011 was investigated. The roll cast AA 8011 was cryogenic rolled for six passes and then annealed. The annealing treatment was adopted at 100–300 °C for 1 h, and then the annealing treatment was adopted at 220 °C for 10–80 min. The microstructures of AA 8011 under roll cast and cryogenic rolled states were studied by using OM. The grain size was calculated by the Image-pro-plus 5.0. The microstructures of AA 8011 under annealing states were observed by using TEM and energy dispersive spectrum analysis. The results show that the second phase Al8Fe2Si appears in the cryogenic rolled AA 8011 after annealing treatment. When the dislocation moves in the grain, the dislocation plays a pinning role, which is conducive to grain refinement. The optical annealing treatment was treated at 220 °C for 40 min with optimal thermal stability. The ideal grain size is 1 μm, hardness is 65 HV, and tensile strength is 202 MPa. It is about 1.5 times of the roll cast AA 8011.

Effect of annealing treatment on the microstructure, mechanical and tribological properties of chromium carbonitride coatings

Chromium nitrides were deposited by RF reactive magnetron sputtering from a Cr target on high carbon steel substrates XC100 (1.17 wt% carbon) in a N2 and Ar gas mixture. In order to investigate the formation of chromium nitrides, carbide and carbonitride compounds were subjected to vacuum annealing treatment for 1 h at various temperatures ranging from 700 to 1000 °C. The samples were characterized by EDS, XPS, XRD, SEM, nanoindentation and tribometry. The results showed the emergence of Cr2N and CrN during the early stages of annealing and the appearance of chromium carbonitride phases only at 900 °C. The (111) preferred orientation of the fcc CrN phase was changed to (002) at 900 °C in parallel with the appearance of chromium carbides. Nanoindentation tests revealed a gradual increase of the Young's modulus from 198 to 264 GPa when increasing the annealing temperature, while the hardness showed a maximum value (H = 22.4 GPa) at 900 °C. The low friction coefficient of the CrCN coating against a 100Cr6 ball was approximately 0.42 at 900 °C. The enhancement of mechanical and tribological properties was attributed to the stronger bonding CrC at the CrN/XC100 interfaces as confirmed by XPS results.

Influence of annealing temperature on structural and optical properties of SnS:Ag thin film for solar cell application

Thermal evaporation method have been used to prepared thin films from tin sulfide (SnS) doping with 20 nm particle size of silver (Ag) at room temperature, under pressure up to 1 × 10-7 mbar with rate of statement 0.5 nm. sec-1. The SnS:Ag thin films deposited on glass substrate at different annealing temperature (as-deposited, 423, 473, 573 and 623 K) for 2 hours. The effect of annealing treatment on the structural and optical properties has been studied. From X- ray diffraction (XRD) examination, predominant peak (111) appears at annealing temperature 623 K, also the others as (101) and (002). Scherer’s formula used to calculate the crystallite size that ranged from 3-7 nm. Using UV-Vis spectrophotometer to recording the transmittance spectra and then calculate the optical properties in the wavelength range 300-900 nm. The absorbance decreased with the increasing of annealing temperature, while the transmittance increased. The optical constants such as refractive index, extinction coefficient, real and imaginary parts of dielectric constant, and absorption coefficient decreased with the increasing of annealing temperature. The energy band gap increased from 2.1 eV for the as- deposited film to 3.3 eV for the film annealed at 623 K.

Effect of annealing treatment on microstructure evolution and creep behavior of a multiphase Ni3Al-based superalloy

The microstructure evolution and creep behavior of a novelly designed as-cast Ni3Al-based superalloy with multiphase configuration are investigated by high-temperature annealing treatments. The as-cast microstructure comprises dominant γ′+γ dendritic and less (~19.37 vol%) interdendritic β areas, annealing treatments at 1160–1280 °C promoted the growth of γ'Ⅰ phase in the γ'+γ dendrite, during which the interdendritic β phase aggregated and coarsened rapidly in width with keeping its relatively constant volume fraction. Meanwhile, the annealing treatments significantly promoted the precipitation of quasi-spherical α-Cr phase particles within the β phase. The original as-cast microstructure exhibited inferior creep resistance at 800 °C/200 MPa with the shortest creep rupture life of 194 h, however, the annealing treatments at 1160–1280 °C prolonged the creep rupture life to beyond 611 h. Although the steady-state creep rate was gradually reduced with increasing annealing temperatures, the creep ductility was degraded by higher-temperature annealing at 1240 and 1280 °C compared with original as-cast microstructure. The 1160 °C annealed microstructure exhibited the longest creep rupture life of 665 h and the maximum creep strain to fracture of 3.21%, while the minimum steady-state creep rate was obtained on account of the largest γ'Ⅰ phase sized 0.91 µm after annealing at 1280 °C. Despite its positive role in the castability, thermoplasticity and weldability of the explored multiphase Ni3Al-based superalloy, interdendritic β phase has negative effects on the creep properties due to its incoherent existence with the dominant γ′+γ dendrite.

Effect of annealing treatment on transparent and conductive hydrated magnesium-carbon films

Transparent electronic technology has many urgent optoelectronic device applications. A key component of plasmonic materials in conventional semiconductors is the wide band gap of oxide thin films. Although transparent electronic materials have been developed for visible and near-infrared wavelengths, systems incorporating mid-infrared and far-infrared spectra are difficult to achieve. In this study, hydrated magnesium-carbon films, a new type of non-oxide transparent conductive thin films with a magnesium hydroxide structure, were generated using the three-step method. After annealing treatment, larger crystals in the thin films typically exhibited superior film resistivity, with conductivity values of approximately 8.63 × 10−3 Ω m. Due to the free electron concentration was not more than 1020 cm−3, the films demonstrated excellent optical properties, with plasma wavelength values of approximately 8 μm for infrared transmittance above 70%. After annealing, due to the Moss-Burstein (M-B) effect, the visible light transmittance was greater than 85% and the optical bandgap shifted towards the blue region. In addition, the influences of the sputtering power of the carbon target on the properties of hydrated magnesium-carbon film were also discussed in this paper.