Annealing Parameters Research Articles

Effect of annealing parameters on the microstructure and tribological properties of FeCoCrNiMn laser cladding layers

The FeCoCrNiMn laser cladding layer exhibits low hardness and poor wear resistance, limiting its applications in the tribology field. The effect of annealing temperature (500 °C-900 °C) and holding time (2 h-14 h) on the properties of FeCoCrNiMn layers which fabricated on the 45# steel substrate were systematically studied. The results demonstrate that the layers' surface hardness and wear resistance initially increase and decrease with increasing annealing temperature and holding time. The FeCoCrNiMn layers subjected to annealing at 700°C for 8h exhibit optimal performance. Specifically, the micro-hardness and wear resistance of the 700°C-8h annealed layers (T700-8) increased by 15.8% and 41.4%, respectively, compared to the substrate. The friction coefficient of T700-8 is 0.635, which is 0.025 lower than that of the substrate. The primary wear mechanisms of the T700-8 are adhesive wear and oxidative wear. Microstructural analysis indicates that annealing at 700°C for 8h forms a Ni-Cr-Fe solid solution phase, strengthening the solid solution. Besides, the average grain size of the layers decreases from 178.7 μm to 115.2μm, indicating grain optimization induced by the annealing process. However, excessively long annealing time or excessively high annealing temperatures lead to the dissolvement of the Ni-Cr-Fe solid solution phase, thus decreasing the surface hardness and wear resistance. Therefore, appropriate annealing parameters can refine the crystal grain, and improve the wear resistance of FeCoCrNiMn layers.

In-depth analysis of sintering, exposure time, and layer height (um) in LRS 3D printed devices with DLP

The technology of 3D printing, referred to as additive manufacturing, is widely acknowledged as a transformative innovation that has the potential to supplant traditional processing methods in numerous domains. The present study showcases a quantitative assessment of the mechanical properties of moon dust, also known as Lunar Regolith Simulants (LRS), printed through vat polymerization. In this study, we conduct a thorough investigation and explore the effects of layer height [LH] (LH = 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm]), exposure time [ET] (ET = 3000 ms, 5000 ms, 7000 ms, 11,000 ms), and sintering impact [1075 °C, 1082 °C, 1083 °C, 1085 °C, 1086 °C, 1087 °C, 1090 °C] on the mechanical properties of printed structures. Herein, we utilize a 55 % volume suspension of LRS to print rod and block configurations via digital light printing [DLP] that are subsequently consolidated through sintering in ambient air. This 55 % LRS via vat polymerization approach has not been previously reported. The morphology of the simulant powders exhibited irregular and angular features. Our experimental results show that a 30 um (LH) with (ET) 11,000 ms exhibits maximum compressive and flexural strength of 330 MPa and 100 MPa at 1085 °C. The sintering atmosphere greatly affects the microstructure, macroscopic features, and mechanical strength of 3D-printed LRS, which reveals diverse chemical compositions and underlying reaction mechanisms. This sintering process improves particle bonding, resulting in densification and reduced voids within the 3D-printed structure. It is essential to optimize the annealing parameters to achieve the desired strength while avoiding excessive sintering that may cause dimensional distortions or structural defects. This innovative approach opens new possibilities for future space exploration and extraterrestrial construction.

Formation of vanadium dioxide nanocrystal arrays via post-growth annealing for stable and energy-efficient switches

The abrupt and reversible semiconductor-metal phase transition in vanadium dioxide nanocrystals has attracted considerable attention for potential applications in oxide electronics, including neuromorphic systems. This study presents a systematic investigation of post-growth annealing conditions for the formation of single VO2 M-phase nanocrystals arrays from VOx films synthesized by atomic layer deposition. The composition of the initial VOx films and the annealing parameters were found to significantly affect the morphology, phase composition and electrical properties of the obtained single nanocrystal arrays. Our results demonstrate that the formation of VO2 M-phase nanocrystal arrays occurs at annealing temperatures of 650 °C and above, irrespective of the initial film composition. More homogeneous in size nanocrystals are formed from initial VOx films with higher V+4 content. The structures with the initial V+4 content of 60 % annealed at 650 °C for 2 h demonstrates the resistive switching with an energy less than 150 fJ, and a total number of stable switching cycles more than 101⁰. Our results pave the way for the novel energy-efficient nanoelectronic and nanophotonic devices based on VO₂ nanoparticles.

Manufacturing the current flow diverter architecture in REBCO tapes using silver inkjet printing

Abstract A low normal zone propagation velocity (NZPV) combined with critical current inhomogeneities favor the nucleation of destructive hot spots in rare-earth barium copper oxide (REBCO) tapes. Increasing the NZPV using the current flow diverter (CFD) concept is a promising solution to mitigate the risk of developing hot spots. The fabrication method of CFD REBCO tapes implies several steps consisting in masking, silver etching, mask removal, and silver deposition, which takes time and remains a barrier to the implementation of a low-cost industrial production of long-length CFD REBCO tapes. This work presents a cost-effective and maskless CFD fabrication approach that relies on inkjet printing (IJP) of silver patterns directly on top of the REBCO layer to create a non-uniform interfacial resistance between the silver and the REBCO surface, along the width of the tape. The parameters of IJP and oxygen annealing were optimized to obtain highly conductive silver patterns deposited on the surface of the REBCO layer. CFD REBCO tapes were successfully fabricated using commercial REBCO tapes and the proposed method without degrading the superconducting properties. Experimental measurements revealed an increase of the NZPV by a factor of 6-7 compared to commercial REBCO tapes.

Influence of Annealing and Aging Parameters on the Microstructure and Properties of 1200 MPa Grade Cold-Rolled Dual-Phase Steel

With the rapid development of the automotive industry, the requirements for bodywork materials are not only focused on high strength but also on improved forming properties. To develop a new generation of automotive steels with higher strength–plasticity matching, a high elongation 1200 MPa grade V-Nb microalloyed cold-rolled reinforced formable dual-phase steel was developed in this experiment through rational compositional design and precise process machining. The properties of the test steel are improved by varying the over-aging temperature as well as the annealing temperature to achieve a good strength–plasticity balance. The results show that as the aging temperature increases, the tensile strength and yield strength of the test steel decrease, while the elongation continues to increase. At an aging temperature of 310 °C, the steel exhibits not only high strength but also better ductility. As the annealing temperature increases, the tensile strength and yield strength of the test steel initially increase and then decrease, while the elongation continues to increase. When the heat treatment process involves an annealing temperature of 860 °C and an over-aging temperature of 310 °C, the test steel achieves the best strength–plasticity balance.

Empirical Model of Low-Ohmic Nickel-Based Contact Formation on N-Type 4H-SiC Depending on Thermal Budget

In this work, an empirical model of structural and material composition of low-ohmic nickel silicide contact formation on n-type 4H-SiC by laser annealing as well as by RTA is presented. For this purpose, systematic studies with different annealing parameters were performed. The development of the empirical model is based on results from characterization of the nickel silicide by FIB-SEM, TEM, XRD analysis as well as electrical characteristics received from 4-point-measurements.

Dark-field microscopy studies of single silicon nanoparticles fabricated by e-beam evaporation technique: effect of thermal annealing, polarization of light and deposition parameters.

Herein, we report the dark-field microscopic studies on single silicon nanoparticles (SiNPs) fabricated using different deposition parameters in the electron beam (e-beam) evaporation technique. The morphology of the fabricated SiNPs is studied using the Atomic Force Microscope. Later, for the first time, the effect of thermal annealing and deposition parameters (i.e., beam current and deposition time) on the far-field scattering images and spectra of single SiNPs is studied using a transmission-mode dark-field optical microscope to estimate the wavelength locations and full-width at half maxima of the optical resonances of single SiNPs. Finally, the role of polarization of incident light on the optical resonances of single SiNPs is also studied by recording their scattering images and spectra.&#xD.

OPTIMIZATION OF ANNEALING AND 3D PRINTING PROCESS PARAMETERS OF PLA PARTS

Fused Filament Fabrication (FFF) has gained significant popularity as the prevalent additive manufacturing technique due to its ability to reduce production time and expenses. However, the constraints of limited dimensional precision, poor surface quality, and relatively low Ultimate Tensile Strength (UTS) hinder compliance with the stringent regulatory norms of conventional manufacturing, necessitating post-processing for enhancement. In this investigation, the response surface method was used to optimize annealing and certain printing parameters in order to enhance the quality of PLA parts produced by FFF. The optimization technique aimed to enhance the UTS and match the CAD dimensions while also minimizing surface roughness. The RSM optimization analysis identified the optimal parameters as: layer height of 0.1 mm, build orientation at 0 degrees, annealing temperature of 110 degrees, and annealing time of 180 dk mm. The proposed models are substantiated by the consistent achievement of high levels of agreement between estimated and experimental response values. A composite desirability value of 0.80 was derived for the variables as a consequence of the optimization investigation.

Impact of Residual Strains on the Carrier Mobility and Stability of Perovskite Films.

Solution-based inorganic-organic halide perovskites are of great interest to researchers because of their unique optoelectronic properties and easy processing. However, polycrystalline perovskite films often show inhomogeneity due to residual strain induced during the film's post-processing phase. In turn, these strains can impact both their stability and performance. An exhaustive study of residual strains can provide a better understanding and control of how they affect the performance and stability of perovskite films. In this work, we explore this complex interrelationship between residual strains and electrical properties for methylammonium CH3NH3PbI3-xClx films using grazing incidence X-ray diffraction (GIXRD). We correlate their resistivity and carrier mobility using the Hall effect. The sin2(ψ) technique is used to optimize the annealing parameters for the perovskite films. We also establish that temperature-induced relaxation can yield a significant enhancement of the charge carrier transports in perovskite films. Finally, we also use Raman micro-spectroscopy to assess the degradation of perovskite films as a function of their residual strains.

A STUDY OF THE EFFECT OF ANNEALING HEAT TREATMENT ON THE FATIGUE PROPERTIES OF 0.17%C HSLA STEELS: A STATISTICAL APPROACH

The present study investigated the effect of annealing heat treatment on the fatigue properties of 0.17%C of HSLA steels using a statistical approach. The Carbon equivalent (CE) was first calculated to determine the ideal starting point for annealing which is 840oC from the Iron Carbon phase diagram. The steel samples were then exposed to multi-régimes of annealing temperatures namely; 840 oC, 870 oC, 900oC, 930oC, 960oC and 990oC at 30oC interval they were then soaked for 30 minutes. Some of the samples were thereafter machined into fatigue samples before being subjected to fatigue test. Quantitative metallography was also carried to examine its microstructure; results showed that for the steel under study, higher annealing temperature improved the fatigue properties significantly. Highest number of cycles being recorded at 3.9 Ⅹ 103 and 1.3 X 103 at 321.3 MPa and 1606.57 MPa stress levels for samples annealed at 990 oC, this is followed closely by samples annealed at 960 oC which had 3.5 X 103 and 0.8 X 103 number of cycles at the same stress levels before failure. The control had the least number of cycles of about 0.9 X 103 and 0.1 X 103 at the same stress levels, and, standard deviation of 5.960 and a mean of 26.881 which shows that annealing greatly improved the fatigue life of the steel. The implemented software (ANOVA) test confirmed the results at 95% confidence which further showed that there was significant difference amid the annealing parameters and, it shows promising results.

Exploring the effect of facile i-line photolithography on the structure and physicochemical properties of photosensitive glass ceramics

Photosensitive glass-ceramics exhibit significant potential to replace silicon materials in the microfabrication of micro-electro-mechanical-system (MEMS) devices. However, they are constrained by the limitations of a conventional 320-nm photolithography process. Therefore, developing an ideal industrial i-line (365 nm) photolithography for Li2O–Al2O3–SiO2 photosensitive glass-ceramics is urgently needed. This study initially explores the impact of a facile i-line photolithography on the structure and physicochemical properties of photosensitive glass ceramics. We experimentally showcase a direct, scalable, and straightforward i-line photolithography technique for Li2O–Al2O3–SiO2 photosensitive glass ceramics. Our research concentrates on how the exposure time affects the properties of Li2O–Al2O3–SiO2 photosensitive glass ceramics, particularly regarding nucleation and crystallization. This is achieved by adjusting the exposure time parameter and utilizing XRD, etching experiments, SEM, TEM, and other tests under a i-line light source. By optimizing the exposure process parameters, we also modify the annealing process parameters affecting the crystallization of lithium metasilicate in the exposed areas. Under a treatment process involving an exposure time of 20 min, a nucleation temperature of 500 °C, a crystallization temperature of 630 °C, and a nucleation/crystallization duration of 2 h, the sample achieves the highest crystal quantity and the optimal thickness-etching rate ratio.

One-Step Fabrication for CsPbBr3 Perovskite Thin Film via a Facile Ion-Solution Spraying Approach

In the current work, a facile ion-solution spraying strategy was employed for one-step fabrication of CsPbBr3 perovskite thin films under atmosphere. The dependences of sample properties on annealing parameters (toleration temperature and duration time) were investigated in detail. As the results suggested, the sample prepared at 200 °C for 15 min featured better properties than others. The sample displayed a cubic phase with good crystallinity, a dense and compact morphology, a bandgap energy of 2.289 eV, and an average decay lifetime of 55.536 ns. Furthermore, the sample presented a Br-rich state, which was favorable for the carrier behavior and structure stability.

P‐111: A Machine Learning Perspective for the Optimization of Annealing Parameters in Solution Processed Thin Film Devices

This work adopts machine learning to refine the annealing process in solution‐processed thin films, such as QDs, perovskites, and organic semiconductors. The annealing temperature and time of PbS QD thin film is optimized using a machine learning algorithm. This method offers a systematic approach to determine the optimal annealing parameters, surpassing the traditional, less‐efficient methods. This adaptive model minimizes human bias, handles complex nonlinear relationships, and capable of optimizing multiple parameters simultaneously. By introducing machine learning algorithm, this method provides a universal and effective strategy for the optimization of parameters during the fabrication of thin films.

Effects of Initial Grain Orientation and Annealing Parameters on Grain Size, Texture, and Magnetic Properties of Ultra-Thin Grain-Oriented Silicon Steel

Effects of Initial Grain Orientation and Annealing Parameters on Grain Size, Texture, and Magnetic Properties of Ultra-Thin Grain-Oriented Silicon Steel

Highly reproducible and CMOS-compatible VO2-based oscillators for brain-inspired computing.

With remarkable electrical and optical switching properties induced at low power and near room temperature (68°C), vanadium dioxide (VO2) has sparked rising interest in unconventional computing among the phase-change materials research community. The scalability and the potential to compute beyond the von Neumann model make VO2 especially appealing for implementation in oscillating neural networks for artificial intelligence applications, to solve constraint satisfaction problems, and for pattern recognition. Its integration into large networks of oscillators on a Silicon platform still poses challenges associated with the stabilization in the correct oxidation state and the ability to fabricate a structure with predictable electrical behavior showing very low variability. In this work, the role played by the different annealing parameters applied by three methods (slow thermal annealing, flash annealing, and rapid thermal annealing), following the vanadium oxide atomic layer deposition, on the formation of VO2 grains is studied and an optimal substrate stack configuration that minimizes variability between devices is proposed. Material and electrical characterizations are performed on the different films and a step-by-step recipe to build reproducible VO2-based oscillators is presented, which is argued to be made possible thanks to the introduction of a hafnium oxide (HfO2) layer between the silicon substrate and the vanadium oxide layer. Up to seven nearly identical VO2-based devices are contacted simultaneously to create a network of oscillators, paving the way for large-scale implementation of VO2 oscillating neural networks.

Domain wall dynamics in stress annealed microwires

In this work we investigate the effect of stress-annealing on the magnetic properties and domain wall dynamics of CoFeNi-based microwires with nearly-zero magnetostriction. Among the annealing parameters whose influence we studied are time and temperature, as well as the magnitude of the stresses applied during annealing. We demonstrate that heat treatment and stress application have the opposite effects on the switching field and domain wall mobility. Therefore, their combination can be used to tune the parameters of the domain wall dynamics over the wide range. We found that stress annealing can increase the domain wall mobility by up to 3 times comparing to annealing without any stress. The maximum domain wall mobility achieved for the studied microwire is 95 m2/sA.

Unexpected texture transition induced by grain growth during static annealing of a dilute Mg-1Al alloy

Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains, resulting in poor formability at room temperature. Therefore, the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets. The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al (wt.%) alloy during various annealed temperatures ranging from 300 °C to 450 °C, have been investigated using the quasi in-situ electron backscatter diffraction (EBSD) method. The as-rolled Mg-1Al alloy shows a dominant basal texture, which weakens and broadens in the rolling direction (RD) during the subsequent annealing, accompanied by the formation of 〈101¯0〉 texture component. Particularly, the 〈101¯0〉 texture component is more pronounced after annealing at high temperatures. The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands, which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45° from the normal direction (ND). Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process, resulting in a reduction in the texture intensity. Moreover, recrystallized grains belonging to the 〈101¯0〉 texture component grow preferentially compared to those with other orientations, which is attributed to low energy grain boundaries, especially grain boundaries with ∼30° misorientation angles. Furthermore, the high temperature annealing facilitates the rapid growth of grain boundaries having a 30° misorientation angle, leading to the occurrence of distinct 〈101¯0〉 texture after annealing at 450 °C for 1 h. The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters.

Refinement of Large Primary Carbides by Adjusting Annealing Parameters in 45Cr9Si3 Valve Steel

Refinement of Large Primary Carbides by Adjusting Annealing Parameters in 45Cr9Si3 Valve Steel

Optimization of laser annealing parameters based on bayesian reinforcement learning

AbstractDeveloping new semiconductor processes consumes tremendous time and cost. Therefore, we applied Bayesian reinforcement learning (BRL) with the assistance of technology computer-aided design (TCAD). The fixed or variable prior BRL is tested where the TCAD prior is fixed or is changed by the experimental sampling and decays during the entire RL procedure. The sheet resistance (Rs) of the samples treated by laser annealing is the optimization target. In both cases, the experimentally sampled data points are added to the training dataset to enhance the RL agent. The model-based experimental agent and a model-free TCAD Q-Table are used in this study. The results of BRL proved that it can achieve lower Rs minimum values and variances at different hyperparameter settings. Besides, two action types, i.e., point to state and increment of levels, are proven to have similar results, which implies the method used in this study is insensitive to the different action types.

Investigating the annealing effects on the performance of polyvinyl alcohol-graphite-based triboelectric nanogenerator

Annealing plays a crucial role in enhancing the performance, stability, and durability of triboelectric nanogenerators (TENGs). By carefully controlling the annealing parameters, the material properties can be optimized and improve the overall efficiency of TENG devices for various practical applications. Herein, graphite (Gr) embedded polyvinyl alcohol (PVA) composite films are prepared by a solution casting technique and subjected to annealing at various temperatures below the glass transition temperature (Tg) of PVA. The annealed effects are thoroughly examined through characterizations involving PXRD, SEM, EDS, FTIR, and TGA. Subsequently, TENGs are fabricated utilizing the annealed composite films as the tribopositive material, polypropylene as the tribonegative material, and the impact of annealing on the device performance is investigated. At an annealing temperature of 80°C, the PVA-Gr TENG exhibited notably higher output voltage (VOC) and short-circuit current (ISC) of 200.24 V and 12.68 µA, respectively. In addition, the PVA-Gr TENG successfully charges electrolytic capacitors, powers a digital watch, operates a humidity and temperature sensor, and lights a series of green LEDs. Thus, the present study highlights the significant impact of annealing on the performance of PVA-Gr TENG, leading to enhanced output power and stability.