Effect Of Annealing Temperature Research Articles

Effects of different annealing temperatures on microstructure, mechanical properties, and magnetic properties of cold-rolled 20Mn23AlV non-magnetic structural steel

Effects of different annealing temperatures on microstructure, mechanical properties, and magnetic properties of cold-rolled 20Mn23AlV non-magnetic structural steel

The Influence of Annealing on the Compositional and Crystallographic Properties of Sputtered Li–Al–O Thin Films

Li–Al–O materials are interesting for several applications. Herein, a Li–Al–O thin‐film materials library, deposited by inert magnetron sputtering and postdeposition annealing in O2 atmosphere, is used to study the effects of different annealing temperatures (300–850 °C) and durations (1 min to 7 h) on crystallinity and composition of the films. X‐ray photoelectron spectroscopy depth profiling reveals inhomogeneous compositional depth profiles of conventionally annealed films (300–650 °C, 3–7 h) with increased Li contents toward the film surface and increased Al contents toward the film–substrate interface, as confirmed by a combination of Rutherford backscattering spectrometry and deuteron‐induced nuclear reaction analysis. The minimum temperature for the formation of crystalline LiAlO2 in the otherwise amorphous films is 550 °C. The undesired inhomogeneous depth profiles are transformed into homogeneous ones by rapid thermal annealing (750–850 °C, 1–10 min), while simultaneously causing the formation of crystalline LiAlO2. Therefore, rapid thermal annealing is shown to be more suitable than conventional annealing for the thermal processing of Li–Al–O thin films. Moreover, this conclusion is expected to have broader relevance beyond Li–Al–O materials, as it is likely to apply to other Li metal oxides, of which there are many technologically relevant ones.

Artificial optoelectronic synapses based on capture layer of silicon rich oxides

The optoelectronic bionic synapse, as a new memory device with integrated storage and calculation, can respond to light stimulation, for use in the bio-visual system. These also have the advantages of large bandwidth, low crosstalk, and low power consumption. In this study, amorphous silicon (Si) films were annealed at 200 °C, 300 °C, 400 °C, and 500 °C, respectively. SiOx defects were introduced at their interfaces and optoelectronic synapses, resulting in the formation of SiOx/a-Si/P++-Si. X-ray photoelectron spectroscopy was used to characterize the effect of different annealing temperatures on the composition of SiOx. The devices successfully simulated a series of important synaptic functions, including excitatory postsynaptic currents, paired-pulse facilitation, short-term to long-term memory conversion, learning-experience behaviors, etc. The devices prepared under different annealing processes had different memory effects. Based on this, a 3 × 3 array of image memory optoelectronic synapse was prepared to simulate the human brain short-term, long-term, and after-repeated memory state, of human beings. Finally, based on the changes in the mode of Si and oxygen binding and the activation energy of oxygen, the reason for the differences in the memory properties of synaptic devices prepared at different annealing temperatures could be explained.

0D/2D CuCo2O4/Ti3C2 hybrid nanostructure as anodic nanocatalyst for direct power generation in fuel cells: Investigating annealing temperature and synergetic effect

In the present work, CuCo2O4 nanoparticles, CuCo2O4/Ti3C2, CuO/Ti3C2, and Co3O4/Ti3C2 hybrid nanostructures were synthesized. Various characterization and electrochemical methods were used for investigating the effect of annealing temperature on the catalytic properties. Based on the results, the hybrid of Ti3C2 MXene nanosheets with CuCo2O4 nanoparticles improved the active surface area and kinetic of electron transfer. The annealing temperature through affecting the crystalline structure, lead to the change in the electrocatalytic performance of nanostructures. On the other, the CuCo2O4/Ti3C2 hybrid nanostructure show better performance than the single metal oxides (CuO and Co3O4) due to the synergistic effect of Cu and Co. Therefore, CuCo2O4/Ti3C2(200) hybrid nanostructure can be used as an efficient nanocatalyst in the electrooxidation process of alcohols in fuel cells due to its higher electrochemical surface area, higher current density (42 mA cm−2) and better stability (83.3 %) compared to other structures.

Tensile behaviors of rolled and annealed 90W7Ni3Fe alloy

Tungsten heavy alloys (WHAs) with two-phase composite structures display unique mechanical properties. Here, we explore the effects of rolling strain and annealing temperature on tensile behaviors of 90W7Ni3Fe WHAs. Cold rolling followed by low-temperature annealing (<1000 °C) induces an increase in yield strength at the expense of ductility. The ductility of WHAs can only be restored by raising the annealing temperature to 1000 °C. Keep the annealing at 1000 °C while gradually increasing the rolling strain not only improves the strength of WHAs but also maintain a good ductility. Once exceeding a critical rolling strain of 60 %, the yield strength of WHAs increases to 1480 MPa, while result in a substantial decrease in ductility. The evolutions of two-phase composite structures with rolling and annealing induces the alterations of the tensile properties of WHAs. These results provide a reference for designing thermal-mechanical processing recipes for WHAs.

Combined effects of substrate temperature and post annealing temperature on structural, optical and electrical properties of Sb-doped SnO2 films

Sb-doped SnO2 (ATO) films have received extensive attention as transparent conductive films, but there is still a lack of in-depth and systematic study on combined effects of substrate temperature (Ts) and annealing temperature (Ta) on their transparent conductive properties. In this study, ATO films were prepared using RF magnetron sputtering at RT∼400 ℃ and subsequently annealed at 200–1000 ℃. The results show that the conductive properties of the films enhance (with a decrease in resistivity from 1.15×10-1 to 2.15×10-3 Ω•cm) and the average visible-light transmittance (TVis) decreases (90.16 → 38.24%) with increase of Ts. With the increase of Ta, the conductive properties of the films prepared at different Ts tend to first enhance and then degrade, and the TVis basically shows a trend of first decreasing and then increasing. After annealing at 600 ℃, the films prepared at RT and 100 ℃ can achieve better comprehensive properties (resistivity of 2.50×10-3 and 1.64×10-3 Ω•cm, carrier concentration of 3.35×1020 and 4.93×1020 cm-3, mobility of 7.73 and 7.76 cm2/V•s, sheet resistance of 84 and 55 Ω/sq., and TVis of 86.63 and 79.50%). In order to explore the intrinsic mechanism of the optical and electrical performance of ATO films changing with Ts and Ta, the preferred orientation, crystallinity, and stress state of the films were analyzed by XRD, and their surface morphology was observed by SEM. Meanwhile, the chemical states of Sn, O and Sb as well as Sb content in the films were analyzed by XPS, and their lattice vibration modes of the film were studied by Raman spectra. Finally, the process-structure-properties correlations were established for the ATO films.

Effect of Annealing Temperature on Microstructure and Properties of Solid Solution Extruded Mg–2.0Zn–1.0Y–0.5Zr Alloys

In this investigation, the effects of different annealing temperatures (180, 200, 220, 240, 260, and 280 °C) on the microstructure evolution and properties of an extruded Mg–2.0Zn–1.0Y–0.5Zr (wt%) magnesium alloys were determined. Optical microscopy (OM), scanning electron microscopy (SEM), immersion corrosion, electrochemical corrosion experiments, and tensile testing were performed. Research has found that combining hot extrusion with subsequent low-temperature annealing significantly improves the strength, plasticity, and corrosion resistance of alloys due to grain refinement and a reduced dislocation density. The alloy was completely recrystallized at an annealing temperature of 240 °C for 4 h after solid solution extrusion, and the grains were fine and uniform, demonstrating the best comprehensive properties. Its corrosion rate, ultimate tensile strength, yield strength, and elongation were 0.454 ± 0.023 mm/y, 346.7 ± 8.9 MPa, 292.4 ± 6.9 MPa, and 19.0 ± 0.4%, respectively. The corrosion mechanism of the specimens under extruded and annealed conditions was analyzed. After annealing at 240 °C for 4 h, the dislocation and bimodal grain structure of the samples were almost eliminated, resulting in uniform and fine grains, which were conducive to the formation of a more uniform and denser oxide film, thus improving the corrosion resistance of the alloy.

Annealing temperature effects on microstructure and magnetic properties of Fe-6.5wt. %Si alloy strips prepared by TSTRC process

The Fe-6.5wt.%Si alloy exhibits remarkable soft magnetic characteristics, such as high magnetic permeability, low coercivity, high resistivity, and nearly zero magnetostriction. These attributes establish it as an ideal material for low-power, low-noise electric motors and transformers. This investigation aimed to assess the impact of annealing temperature (ranging from 800 to 1200 °C for 1 h) on the microstructure, texture, and magnetic properties of a 0.15 mm thick Fe-6.5wt.%Si alloy sheet, which was obtained by subjecting the strips produced through the top side-pouring twin-roll casting (TSTRC) process to multi-pass warm rolling in the temperature range of 600 ∼ 800 °C, avoiding hot rolling. Additionally, the recrystallization mechanism of the annealed sheet at 1100 °C for 1 h was explored. The findings indicate that enhancing the annealing temperature corresponded to a reduction in magnetic induction (B8 and B50) as well as iron losses (P10/50, P10/400, and P2/1000). The annealed sheet at 1200 °C for 1 h demonstrated the most favorable magnetic properties, displaying iron losses of 0.486 W/kg, 6.895 W/kg, and 1.232 W/kg for P10/50, P10/400, and P2/1000, respectively. These results illustrate excellent overall magnetic characteristics. The coercivity (Hc) of both B8 and B50 decreased as the annealing temperature increased in the hysteresis loop measurements. Specifically, for B8, it decreased from 62.84 A/m to 24.50 A/m, and for B50, it decreased from 78.10 A/m to 35.50 A/m. The average grain size of the samples gradually increased as the annealing temperature ranged from 800 to 1200 °C. The dominant texture observed was {111}, and the volume fraction of {111} texture increased while the volume fractions of {100} and {110} textures decreased. Upon annealing at 1100 °C for 8 s, the elongated and flattened deformed structures were mainly replaced by equiaxed grains, indicating the completion of the recrystallization process. However, there was a noticeable distinction in the coarsening degree of equiaxed grains based on their orientations. The presence of λ-oriented grains was less prominent, while α-oriented and γ-oriented grains were relatively more abundant. As the annealing time increased from 8 s to 1 h, there was a decrease in the presence of λ-oriented and α-oriented grains, while the presence of γ-oriented grains significantly increased.

Mitigation of strength-ductility trade-off of CoCrNi medium entropy alloys with heterogenous structure by controlled Gd addition and annealing

In this work, we synthesized a series of (CoCrNi)100–xGdx (x = 0/0.3/0.5/1.0) medium entropy alloys (MEAs) using arc melting followed by homogenization, hot-rolling, and annealing at 700, 800, and 900 °C for 1 h. The effects of Gd content and annealing temperature on the microstructures and mechanical properties of Gd-doped CoCrNi MEAs were investigated. The heterogenous microstructure, consisting of the deformed grains, recrystallized grains and precipitates of GdNi5 phase, was obtained in the present study and it exhibited an excellent combination of strength and ductility. The optimum mechanical properties were obtained for CoCrNi MEA with 0.3–0.5 at.% Gd addition and annealed at 700 °C for 1 h to yield the heterogenous microstructure in the present study, and it had the tensile strength of ∼1.3 GPa and fracture strain of 30–40%. The synergetic hardening mechanisms included solid solution, precipitation, grain refinement, nanotwinning and pre-existing dislocation hardening. The relations among compositions, microstructures and mechanical properties of (CoCrNi)100–xGdx MEAs were addressed.

Microstructure and Mechanical Properties of a New TWIP Steel under Different Heat Treatments.

The effects of solution treatment and annealing temperature on the microstructure and mechanical properties of a new TWIP steel that was alloyed from aluminum (Al), silicon (Si), vanadium (V), and molybdenum (Mo) elements were investigated by a variety of techniques such as microstructural characterization and room tensile testing. The austenite grain size grew slowly with the increase in annealing temperature. The relatively weak effect of the solution treatment and annealing temperature on the austenite grain size was attributed to the precipitation of MC and M2C, which hindered the growth of the austenite grain. The plasticity of the TWIP steel in cold rolling and annealing after solution treatment was obviously higher than that in cold rolling and annealing without solution treatment. This was because the large-size precipitates redissolved in the matrix after solution treatment, which were not retained in the subsequently annealed structure. Through cold rolling and annealing at 800 °C after solution treatment, the prepared steel exhibited excellent strength and plasticity simultaneously, with a yield strength of 877 MPa, a tensile strength of 1457 MPa, and an elongation of 46.1%. The strength improvement of the designed TWIP steel was mainly attributed to the grain refinement and precipitation strengthening.

Effect of Cobalt Ion Concentration and Thermal Annealing Temperature on Structural and Magnetic Properties of CoFe2O4 Nanoparticles

Effect of Cobalt Ion Concentration and Thermal Annealing Temperature on Structural and Magnetic Properties of CoFe2O4 Nanoparticles

Effect of lanthanum substitution and annealing temperature on the structural and morphological properties of M-type calcium hexaferrite

To investigate the influence of annealing temperature and lanthanum substitution on the structural properties of M-type calcium hexaferrite, we prepared unsubstituted and lanthanum-substituted Ca1-xLaxFe12O19 (x = 0.3, 0.4 and 0.5) powders by mean of sol–gel auto-combustion procedure, annealed between 800 °C and 1350 °C during 5 h in a rate of 180 °C per hour. XRD analysis showed that the M-type phase does not appear in the unsubstituted samples even with annealing at 1200 °C. The XRD patterns of the substituted samples contained peaks of the M-type phase with the presence of α-Fe2O3 as a secondary phase, the intensity of α-Fe2O3 decreased with increasing annealing temperature between 1200 °C and 1350 °C, and also as a function of lanthanum substitution concentration, which shows that the best lanthanum substitution concentration was x = 0.5. Lattice parameters of synthesized Ca0.5La0.5Fe12O19 align with literature results of various M-type hexaferrite. SEM micrographs of the Ca0.5La0.5Fe12O19 annealed at 1350 °C revealed that the mean and median crystallite size values were calculated to be 4.37 μm and 4.32 μm respectively.

Enhanced mechanical and tribological properties of 3D printed short carbon fiber reinforced polyether ether ketone composites

AbstractMaterial extrusion additive manufacturing provides an effective solution for fabrication of highly customized polyether ether ketone (PEEK) composite parts with any complex shape. Nevertheless, compared with conventional methods, the mechanical strength of 3D printed carbon fiber reinforced PEEK (CF/PEEK) composites is unsatisfactory due to the weak interface bonding strength and high voids content induced by the temperature difference. To overcome this challenge, a temperature‐control 3D printer was used to investigate the effects of ambient temperature and annealing temperature on the microstructure, crystallization behavior and mechanical properties of 3D printed parts. Moreover, the tribological properties of parts printed at different ambient temperature were also studied under various contact pressure. Experimental results showed that the ambient temperature and annealing treatment directly affected the interfacial bonding (fiber/matrix, filament/filament, layer/layer), crystallinity of printed samples, thus affecting their mechanical and tribological properties. The CF/PEEK parts printed at high ambient temperature of 200°C exhibited outstanding mechanical and tribological properties. This study has positive significance for promoting the application of 3D printed PEEK composites in the field of structural load‐bearing and friction materials.Highlights Structure–property relationships for 3D printed CF/PEEK composites. The ambient temperature strongly affects the thermal and microstructural properties Interaction between crystallization and molecular interface diffusion. Interfacial bonding and crystallinity determine the mechanical properties. Tribological properties are highly dependent on applied pressures.

Effect of intercritical annealing temperature on microstructure and mechanical properties of V-Ti-Mo microalloyed medium Mn steel

The effect of intercritical annealing temperature on the microstructure and mechanical properties of V-Ti-Mo microalloyed medium Mn steel were investigated using a scanning electron microscope, electron backscatter diffraction, X-ray diffraction and transmission electron microscope. The results showed that the microstructure of the experimental steel in the hot rolled state and after annealing at different temperatures consisted of martensite and reverted austenite. As the annealing temperature increased, the content of reverted austenite increased linearly and reached a maximum value of 29.08 % after annealing at 650 °C. It was difficult to occur austenitic reverted transformation at an annealing temperature of 580 °C. In addition, block-like reverted austenite appeared after annealing at 600 °C, and the austenite size had the largest after annealing at 650 °C. With the increase of annealing temperature, the mass fraction of M3C particles decreased gradually, while that of MC particles increased progressively. Specifically, the mass fraction of 1–5 nm sized MC particles increased first and then decreased, indicating the precipitation strengthening effect was enhanced initially and then weakened. As the annealing temperature rose, the yield strength and tensile strength of the steels decreased gradually, whereas the elongation and impact energy gradually increased. The steel annealed at 650 °C exhibited optimal comprehensive mechanical properties, with a strength-ductility product reaching 26.8 GPa· %.

Effect of annealing on corrosion resistance and mechanical properties of Cr–Fe–Ni–Co–Mo–Si–B amorphous coating

Cr–Fe–Ni–Co–Mo–Si–B amorphous coating was successfully prepared on 316 L steel using atmospheric plasma spraying (APS). The effects of different annealing temperatures on the crystallization process of amorphous coatings, thus on the corrosion resistance and mechanical properties of coatings were studied. The results indicated that heat treatment can increase the hardness of the amorphous coating by 12.5% and reduce the wear rate by 30%. In addition, compared to heat-treated coatings, the amorphous coating had the highest corrosion voltage (−0.506V) and lower corrosion current (5.609 × 10−6 A). The passivation film on the amorphous coating provided the best protection due to the relatively high content of Cr2O3. The molecular dynamics (MD) calculation results also indicated that the adsorption energy of hydrogen chloride molecules on Cr–Fe–Ni–Co–Mo–Si–B amorphous coating (−90.94 kcal/mol) was greater than that of 316 L (−293.03 kcal/mol).

The effect of different annealing temperatures on the mechanical and tribological properties of the Ti2AlN MAX phase films

Ti2AlN MAX phase films produced at different N2 flow rates and different annealing temperatures were deposited on 52100 steel substrates using the closed-field unbalanced magnetron sputtering technique. N2 flow rates were changed to 2, 3.5, and 5 sccm. Due to the increasing N2 flow rate, film thickness decreased from 2 to 1.3 µm. Then the produced films were subjected to annealing at temperatures of 700, 750, and 800°C. After the film produced at a flow rate of 2 sccm was annealed at 750°C, the presence of the Ti2AlN MAX phase was determined. The binding energies of Ti 2p, Al 2p, and N 1s determined in the XPS analysis confirmed the existence of the Ti2AlN film. The friction coefficient measured for Ti2AlN MAX phase films was calculated as 0.53, the hardness value as 22.8 GPa, the elastic modulus as 291.4 GPa, and the wear rate as 2.96 × 10−4 mm3/(N·m).

Effect of Annealing Temperature and Time on the Magnetic Properties and Magnetic Anisotropy of a Temper-Rolled, Semi-processed Non-oriented Electrical Steel

The effect of final annealing temperature and time on the core loss, magnetic permeability, and magnetic anisotropy of a temper-rolled, semi-processed 0.5 wt.% Si non-oriented electrical steel was investigated. The magnetic properties of the steel sheets at 50–400 Hz and 0.5–1.50 T were measured by the Epstein frame method on strips cut along both the rolling (RD) and transverse directions (TD). Optimal magnetic properties were obtained when the annealing temperature was at 800–825°C, and the annealing time was 2–4 h. Relatively large magnetic anisotropy between the RD and TD was observed in samples after recrystallization (~ 10% in core loss and ~ 70% in relative permeability), while deformed and non-recrystallized samples showed small anisotropy in magnetic properties. Regardless of the processing state of the steel, i.e., temper-rolled, recovered, or recrystallized, the core loss followed quadratic polynomial functions with respect to both the frequency and magnetic flux density, while the relative magnetic permeability followed cubic polynomial functions with respect to both the frequency and magnetic flux density. The microstructure and texture of selected samples were characterized by electron backscatter diffraction, which revealed the correlations between the magnetic properties of the steel and the microstructure and texture.

Annealing Temperature Effect on the Physical Properties of NiO Thin Films Grown by DC Magnetron Sputtering

AbstractNickel oxide is a promising material for transparent electronics applications. This semiconductor demonstrates the possibility of modifying its physical properties depending on the method of growth and subsequent processing. Here the effects of the discharge power are reported during reactive dc magnetron sputtering, as well as the modes of subsequent annealing of NiO films, on their structural, electrical, and optical properties. NiO films are annealed at various temperatures both in an oxygen‐containing environment and under vacuum conditions. Deposited NiO films have a polycrystalline structure with a preferred orientation (200) for the low discharge power mode and (111) for the high discharge power mode. However, obtained NiO films exhibit crystallinity improvement after annealing. The presence of both Ni2+ and Ni3+ oxidation states in the deposited films is found. In addition, it is shown that the relative carrier concentration (Ni3+/Ni2+ peak area ratio) can be controlled by choosing the NiO film preparation mode. The trend in this ratio corresponds to the trend in film conductivity and the number of free‐charge carriers. The deposited films are semitransparent, and the estimated optical bandgap of NiO is in the range from 3.50 to 3.74 eV.

Microstructure, texture and magnetic properties of the semi-processed strip-cast non-oriented electrical steel

{100}&lt;0vw&gt; texture is the favorable texture in non-oriented electrical steels (NOES). However, the conventional processes are difficult to produce NOES with strong {100}&lt;0vw&gt; texture. In this study, the 0.35 mm thick 3.1% Si NOES with strong {100}&lt;0vw&gt; texture was produced by the top-side pouring twin-roll casting, cold rolling with or without intermediate annealing, and final annealing process. The microstructure and texture were characterized by optical microscopy, X-ray diffraction and electron backscatter diffraction. Compared to the one-stage cold-rolled strip-cast NOES, the semi-processed (two-stage cold-rolled) strip-cast NOES with intermediate annealing at 650 °C and 700 °C have stronger {100}&lt;0vw&gt; texture and better magnetic properties. The reason is that the semi-processing method can avoid the encroachment on {100}&lt;0vw&gt; grains by other oriented grains, which can encroach on the {100}&lt;0vw&gt; grains by strain-induced grain boundary migration mechanism. Furthermore, the effect of intermediate annealing temperature on the microstructure, texture, and magnetic properties of the semi-processed strip-cast NOES were studied.

Optical, morphological and electrical properties of rapid thermally annealed CoPc/n-Ge heterostructures for photodiode applications

Effect of rapid thermal annealing (RTA) temperature on electrical, morphological and optical properties of cobalt phthalocyanine (CoPc)/n-Ge heterostructures is investigated. UV–Vis measurements of as-deposited and annealed CoPc thin films show the presence of Q band transition at 618 nm and 690 nm absorption wavelength suggesting π-π* transitions. A phase transition is evidenced for the 300 °C annealed CoPc sample. Further, no degradation of Q band intensities is noticed which signifies highly stable CoPc thin films even after annealing at 400 °C. AFM measurements of CoPc thin film on Ge substrate reveal an increased RMS roughness with increased annealing temperature until 200 °C and further roughness was found to be decreased for the sample annealed at 300 °C. A clear change in the morphology of CoPc thin films is observed for the 300 °C annealed sample than 200 °C annealed sample which shows an evidence for the phase transition of CoPc thin films from α-phase to β-phase. This phase transition of CoPc thin films was also confirmed using XRD measurements. FESEM with EDS measurements were carried out for the as-deposited and annealed heterostructures. The surface topography of all the samples reveals a spherical-grained morphology and the grains seem to be highly dispersed in 400 °C annealed CoPc/Ge layers. The electrical and current transport mechanisms of the Au/CoPc/n-Ge heterostructure have been explored at different annealing temperatures by using I–V and C–V characteristics. Notably, the results reveal that superior barrier parameters are observed for the heterostructure annealed at 300 °C than as-deposited heterostructure. Rapid thermal annealing of the Au/CoPc/Ge heterostructure shows its promising applications in the areas of optoelectronic or photoresponsive devices.