In this work, an artificial neural network model is established to understand the relationship among the tensile properties of as-printed Ti6Al4V parts, annealing parameters, and the tensile properties of annealed Ti6Al4V parts. The database was established by collecting published reports on the annealing treatment of selective laser melting (SLM) Ti6Al4V, from 2006 to 2020. Using the established model, it is possible to prescribe annealing parameters and predict properties after annealing for SLM Ti-6Al-4V parts with high confidence. The model shows high accuracy in the prediction of yield strength (YS) and ultimate tensile strength (UTS). It is found that the YS and UTS are sensitive to the annealing parameters, including temperature and holding time. The YS and UTS are also sensitive to initial YS and UTS of as-printed parts. The model suggests that an annealing process of the holding time of fewer than 4 h and the holding temperature lower than 850°C is desirable for as-printed Ti6Al4V parts to reach the YS required by the ASTM standard. By studying the collected data of microstructure and tensile properties of annealed Ti6Al4V, a new Hall-Petch relationship is proposed to correlate grain size and YS for annealed SLM Ti6Al4V parts in this work. The prediction of strain to failure shows lower accuracy compared with the predictions of YS and UTS due to the large scattering of the experimental data collected from the published reports.

In the present work, the effect of annealing temperature on the microstructure, mechanical and tribological properties of NiCr–WC–Co coatings produced by the high-velocity oxy-fuel (HVOF) technique has been investigated. X-ray diffraction and scanning electron microscopy revealed the dissolution of WC into the NiCr matrix to form W2C and Cr3C2 with the annealing process. This dissolution became complete at 800 °C. The mechanical properties of the coatings were investigated using nano-indentation and Vickers fracture toughness measurements. These measurements suggested that the hardness, Young's modulus, and fracture toughness values increased because of the newly formed carbide phases as a result of the dissolution of the WC particles. The overall properties of the coatings were found to be optimum for annealing temperatures of 800 °C. The wear mechanism appears to be abrasive in the as-sprayed coating, and it becomes a combination of an abrasive and oxidative wear with increasing the annealing temperature.

The formation of shear bands during hot deformation of a two-phase (α2 + γ) titanium aluminide and its consequences on dynamics softening has been investigated. The starting material consists of a colony of lamellar grains along with the segregated vanadium and niobium which was subjected to hot deformation in the temperature range 1000–1175 °C at the strain rate 10 s−1. Microstructures of the deformed samples indicate that, with increase in the deformation temperature, the orientation of shear bands changes. Moreover, the extent of dynamic recrystallization also increases with deformation temperature. The softening behaviour and crystallographic orientation change within lamellae during hot deformation have been explored. The nucleation of newly recrystallized grains has been observed at twin–parent grain boundary and within the twined γ phase. Lamellae of the γ and α2 phase have been also observed to be twisted and tilted, leading to the band formations under the load, whose mechanisms have also been explored in the present study.

Graphene enticed the scientific community for its interesting properties since its discovery. Among different synthesis routes of graphene, reduction of graphene oxide (GO) is mostly preferred because of scalability and advantage of modulation of properties of the end product. Thermal reduction of GO is considered to be the simplest and economic among different reduction techniques. The current work reports an experimental analysis of the structural evolution of GO to reduced graphene oxide (rGO) during thermal treatment. GO has been thermally annealed at an optimized temperature of 350 °C in ambient. Thermal reduction is observed after 7 min of annealing and confirmed by shifting of the first major peak from 12° to 23° in X-ray diffraction pattern. Significant carbon content enrichment and exfoliation are two aspects of the thermal reduction of GO. Carbon content suddenly enriches from 38 wt% in GO to 77 wt%. Exfoliation is confirmed by morphological alterations and decrease in carbon layers from eleven to three.

To study the interface characteristics between substrates and homoepitaxially grown single crystalline diamond layers, the high-pressure/high-temperature Ib diamond seeds with homoepitaxial diamond layers were annealed by low-pressure/high-temperature treatment in a hydrogen environment. The stress evolution and related impurity transformation near the interface were characterized by Raman spectroscopy, photoluminescence, and micro-infrared spectroscopy before and after annealing. It is found that the stress is the smallest in a 100 μm wide zone near the interface, accompanying with the similar change in substitutional nitrogen (Ns) concentration. After annealing at 1050 °C, 1250 °C, and 1450 °C, the local compressive stress is released gradually with temperature change. It is decreased by 1.03 GPa in maximum after annealing at 1450 °C. The concentration of nitrogen–vacancy (NV) complexes in the chemical vapor deposition (CVD) layer is dramatically reduced at 1450 °C. The value of ${{I_{{\rm{NV}}^ \hbox- } } \mathord{\left/ {\vphantom {{I_{{\rm{NV}}^ - } } {I_{{\rm{diamond}}} }}} \right. \kern-\nulldelimiterspace} {I_{{\rm{diamond}}} }}$ decreases much more than ${{I_{{\rm{NV}}^0 } } \mathord{\left/ {\vphantom {{I_{{\rm{NV}}^0 } } {I_{{\rm{diamond}}} }}} \right. \kern-\nulldelimiterspace} {I_{{\rm{diamond}}} }}$ in the CVD layer, which is due to the lower stability of NV− compared with NV0 at high temperature.

Titanium (Ti) has been extensively used in medical devices owing to their low density, high strength, excellent corrosion resistance, and biocompatibility. However, thrombus formation and bacterial infections are still challenges for their application in specific clinical cases. Hence, we have developed a simple, efficient, and stable strategy that endow Ti with anticoagulant and antibacterial properties through chemical bonding and electrostatic bonding. A large number of hydroxyl groups were produced on the surface of Ti by annealing at 500 °C. Then, heparin was immobilized on annealed surface with chemical bonding and chitosan was captured in an electrostatically bound manner by simply soaking in solution. The results indicated that the surface-functionalized Ti exhibited excellent anticoagulant properties by a reduction in platelet adhesion and prolonged blood clotting time. Furthermore, the modified Ti also showed antibacterial properties against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

The phase evolution of reactive radio frequency (RF) magnetron sputtered Cr0.28Zr0.10O0.61 coatings has been studied by in situ synchrotron X-ray diffraction during annealing under air atmosphere and vacuum. The annealing in vacuum shows t-ZrO2 formation starting at ∼750–800 °C, followed by decomposition of the α-Cr2O3 structure in conjunction with bcc-Cr formation, starting at ∼950 °C. The resulting coating after annealing to 1140 °C is a mixture of t-ZrO2, m-ZrO2, and bcc-Cr. The air-annealed sample shows t-ZrO2 formation starting at ∼750 °C. The resulting coating after annealing to 975 °C is a mixture of t-ZrO2 and α-Cr2O3 (with dissolved Zr). The microstructure coarsened slightly during annealing, but the mechanical properties are maintained, with no detectable bcc-Cr formation. A larger t-ZrO2 fraction compared with α-Cr2O3 is observed in the vacuum-annealed coating compared with the air-annealed coating at 975 °C. The results indicate that the studied pseudo-binary oxide is more stable in air atmosphere than in vacuum.

The LiCoO2 films were directly deposited on stainless steel (SS) using medium-frequency magnetron sputtering, and the effects of annealing parameters, such as ambiences, temperatures, holding times, and heating rates, were systematically compared based on surface morphologies, crystal structures, and electrochemical properties. The results demonstrate that an aerobic atmosphere with 3.5 Pa is the most important parameter to maintain the performance of LiCoO2 films. The influence of the annealing temperature (>550 °C) ranks second because the formed (101) or (104) planes of LiCoO2 facilitate Li+ migration. A short holding time of 20 min and a moderate heating rate of 3 °C/min are selected to reduce the oxidation or inter-diffusion between the LiCoO2 films and the SS substrate. Finally, the optimal annealing process is confirmed and corresponds to the initial discharge capacity of 37.56 μA h/(cm2 μm) and the capacity retention of 83.81% at the 50th cycle.

A novel solid-clad-by-liquid method was developed to form a 10-m long by 10-mm wide by 80-μm thick Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite tape. Three deformation routes (cold rolling, cold rolling with intermediate annealing, and cold rolling combined with warm rolling) have been investigated in short Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite substrate. To optimize the dynamic continuous annealing parameters for the long composite substrates, air-cooled and furnace-cooled annealing procedures were compared in short Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite substrates. Improved cube texture of 98.7% in a 10-m long by 10-mm wide by 80-μm thick Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite substrate was achieved via warm rolling deformation at 550 °C and two-step dynamic continuous annealing (750 °C for 1 h followed by 1200 °C for 1 h). The yield strength, Curie temperature, and saturation magnetization of 176 MPa, 324 K, and 18 emu/g, respectively, were obtained.

This article mainly focuses on stabilization treatments that influence stress corrosion resistance of an AA5383-H15 alloy after undergoing sensitization treatment at 100 °C/168 h. The results show that without stabilization of the sensitized AA5383-H15 alloy, the β precipitates are distributed continuously like a mesh at grain boundary, and this is the main cause of intergranular corrosion failure. However, applying 3 different stabilization treatments (220 °C/3 h, 250 °C/3 h, and 280 °C/3 h) to the AA5383-H15 alloy shows a dramatic decrease in the β phase precipitation routes along the grain boundaries after the sensitization treatment, and thus an effective improvement in the corrosion resistance performance of AA5383-H15 alloys. Of all the stabilization treatments, the application of 250 °C/3 h stabilization treatment is found to be most effective. Applying 250 °C/3 h stabilization treatment facilitated partial recrystallization of the matrix, leading to suppress the continuous precipitation of the β phase along the grain boundaries during sensitization but instead precipitate in discontinuous mesh-like distribution, which can decrease its sensitivity to stress corrosion.

The effect of severe warm rolling on microstructure and texture homogeneities was investigated in a lamellar (L12 + B2) AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA). The EHEA 90% warm-rolled at 400 °C showed disordering of the L12 phase and a remarkable increase in hardness. A much finer microstructure was observed on ND-RD (Normal Direction-Rolling Direction) plane as compared with that on the RD-TD (Rolling Direction-Transverse Direction) plane. The L12/Face Centered Cubic (FCC) phase developed α-fiber texture ND//〈110〉 with a particularly strong brass ({110}〈112〉) component, while the B2 phase developed the usual RD (//〈110〉) and ND (//〈111〉) fibers. Nevertheless, inhomogeneities in texture were noticed. Upon annealing at 800 °C, the ND-RD showed an ultrafine microduplex structure, while the RD-TD showed a retained lamellar structure. A rather uniform microduplex structure evolved after annealing at 1200 °C due to the accelerated kinetics of transformation at higher temperatures. The L12/FCC phase showed the retention of the α-fiber components, while the B2 phase showed stronger ND-fiber after annealing, although inhomogeneities in texture existed.

Polymeric conjugated materials are convenient for developing future soft-material-based semiconductors, conductors, electronic and optoelectronic devices due to their inherent features. Similar to their inorganic counterparts, the addition of certain minority molecules, or dopants, to polymeric conjugated materials can significantly alter the electronic and optoelectronic properties of the host conjugated polymers or composites. This allows for tunability of a variety of electronic and optoelectronic applications. One way to improve device performance is through the process of thermal annealing. Annealing allows for a polymer matrix to self-assemble into a lower energy state, which leads to an increase in crystallinity and higher charge mobility. Previous research does not explicitly define how dopants can affect this process. This study involves an evaluation of the effects of annealing with doped P3HT films to demonstrate changes in optoelectronic and electronic properties.

Polymeric conjugated materials are very promising for developing future soft material-based semiconductors, conductors, electronic and optoelectronic devices due to their inherent advantages such as flexibility, low-cost, ease of processability, and decreased harmful waste. Like their inorganic counterparts, the addition of certain dopants can significantly alter the electronic and optoelectronic properties of the host conjugated polymers or composites allowing modification for a variety of electronic/optoelectronic applications. One way to improve device performance is through the process of thermal annealing. Annealing allows for polymer matrices to self-assemble into a lower energy state which typically leads to increased crystallinity and higher charge mobility. In this work, we plan to evaluate the effects of annealing on doped P3HT films to understand its effects on optoelectronic and electronic properties focusing solely on crystallinity and charge carriers. Further understanding of the connection between annealing and doping in polymeric conjugated materials and thermoelectric properties will allow for an increase net output from multi-function materials and devices.

Graphene specimens produced by chemical vapor deposition usually show p-type characteristics and significant hysteresis in ambient conditions. Among many methods, current annealing appears to be a better way of cleaning the sample due to the possibility of in-situ annealing in the measurement setup. However, long-time current annealing could increase defects in the underlying substrate. Studying the hysteresis with different anneal currents in a graphene device is, therefore, a topic of interest. In this experimental work, we investigate electron/hole transport in a graphene sample in the form of a Hall bar device with a back gate, where the graphene was prepared using chemical vapor deposition on copper foils. We study the hysteresis before and after current annealing the sample by cooling down to a temperature of 35 Kfrom room temperature with a back-gate bias in a closed cycle refrigerator.

A supersaturated single-phase Cu–26 at.% Co alloy was produced by high-pressure torsion deformation, leading to a nanocrystalline microstructure with a grain size smaller than 100 nm. The nonequilibrium solid solution decomposed during subsequent isothermal annealing. In situ high-energy X-ray diffraction was used to map changes linked to the separating phases, and the development of a nanoscale Cu–Co composite structure was observed. To gain further information about the relationship of the microstructure and the mechanical properties after phase separation, uniaxial tensile tests were conducted on as-deformed and isothermally annealed samples. Based on the in situ diffraction data, different isothermal annealing temperatures were chosen. Miniaturized tensile specimens with a round cross section were tested, and an image-based data evaluation method enabled the evaluation of true stress–strain curves and strain hardening behavior. The main results are as follows: all microstructural states showed high strength and ductility, which was achieved by a combination of strain-hardening and strain-rate hardening.

Refractory high-entropy alloys (RHEAs) have recently attracted much attention, primarily due to their mechanical properties at elevated temperatures. However, the equilibrium phase-stability of these alloy systems is not well established. The present investigation focuses on the phase stability of Al0.5NbTa0.8Ti1.5V0.2Zr RHEA at temperatures ranging from 600 to 1200 °C. The detailed phase characterization involves coupling of scanning electron microscopy, transmission electron microscopy, and atom probe tomography. The stable phases present at these temperatures are (i) 1200 °C—body-centered cubic (BCC) matrix with nano-B2 precipitates; (ii) 1000 °C and 800 °C—a BCC matrix phase with Al–Zr rich hexagonal closed packed intermetallic precipitates and, (iii) 600 °C—a BCC + B2 microstructure, comprising a continuous BCC matrix with discrete B2 precipitates. These results highlight the substantial changes in phase stability as a function of temperature in RHEAs, and high-entropy alloys in general, and also the importance of accounting for these changes especially while designing alloys for high temperature applications.

Pyrrhotites in polished sections from more than twenty stratabound massive sulphide and magmatic nickel-copper deposits in Norway were studied under the microscope using the magnetic colloid method. In both types of deposits, two distinct styles of intergrowths between monoclinic and hexagonal pyrrhotites were found: crystallographically-controlled lamellar intergrowths and fissure-controlled irregular intergrowths.

Lamellar intergrowths consist of crystallographically oriented monoclinic lamellae occurring in a hexagonal matrix and were produced originally by exsolution from hexagonal pyrrhotite on cooling. Irregular intergrowths comprise blades and patches of monoclinic pyrrhotite occurring along fissures and grain boundaries of hexagonal pyrrhotite, and were formed by interactions between hexagonal grains and sulphur-rich hydrothermal solutions.

Increase in lamella thickness and spacing, development of lamella zonations, wedge-shaped composite ends, boxworks and composite lamellae were caused by progressive lamellae coarsening and maturation during natural annealing, which could have been promoted by anisotropic stress. Metamorphic recrystallization and annealing tend to homogenize pyrrhotite and erase preexisting exsolution lamellae.

Coronas of symplectic pargasite [XMg = 68, XCa = 69, XSi = 68] + spinel [SP45] and orthopyroxene [EN70] separate cumulus plagioclase [AN64] and olivine [FO64] in troctolitic gabbro from Risör, Norway. Coronas with a primary microstructure characterized by low-angle grain boundaries have the mineral assemblage layer sequence,

PLAGIOCLASE : PARGASITE + SPINEL : ORTHOPYROXENE + SPINEL : ORTHOPYROXENE : OLIVINE, whereas those with an annealed microstructure have the layer sequence,

PLAGIOCLASE : PARGASITE + SPINEL : PARGASITE : ORTHOPYROXENE : OLIVINE.

Primary symplectite consists of fan-shaped grains of pargasite that open toward plagioclase and are ribbed by rods of spinel. On annealing to a single grain, low-angle grain boundaries disappear and spinel rods rotate into parallel positions. Primary orthopyroxene, initially radial to layer contacts, anneals to a single grain, rimming olivine. Irregular discontinuous layers and plumes of symplectic orthopyroxene+spinel disappear on annealing and a monomineralic layer of pargasite forms between orthopyroxene and the amphibole symplectite.

The identity of composition of intercumulus pargasite and orthopyroxene with the same phases in primary coronas, the occurrence of primary and annealed coronas rimming cumulus ilmenite and the occurrence of radial orthopyroxene separating grains of cumulus olivine and separating cumulus olivine and plagioclase argue for the origin of primary coronas by fractional crystallization of spinel-saturated troctolitic magma at a pressure greater than 5 kbar.

Irreversible thermodynamic calculations show that the mineral assemblage layer sequence of the primary coronas is diffusionally unstable and that this instability provides the driving force for their spontaneous transformation to the stable mineral assemblage layer sequence of the annealed coronas.

Al–12.6Si was annealed at both 500 and 560 °C for different lengths of time in this study. Additionally, the effects of annealing treatment on the spheroidization of eutectic Si and the mechanical properties of the Al–Si alloy have been investigated. The morphology of these particles was described using surface shape factor (φ), and it was found that the optimal annealing time of Al–12.6Si at 500 and 560 °C is seven hours and five hours, respectively. The average size of the Si particles in the Al–Si alloy annealed at 500 °C is less than that of the particles at 560 °C. The roundness of the Si particles within the Al–Si alloy annealed at 500 °C is slightly better than that at 560 °C. The elongation of the alloy apparently increases, while the tensile strength of the Al–Si alloy decreases. The tensile strength and elongation of the eutectic Al–Si alloy annealed at 500 °C is higher than that at 560 °C.