Effect Of Low Temperature Heat Treatment Research Articles

The effect of low-temperature heat treatment on hydrogen embrittlement of sheared edge in advanced high-strength steels

Hydrogen embrittlement (HE) has become an important issue in ultra-strong automotive steel applications. This study investigated the HE mechanism of the sheared edge in complex phase (CP) steel and examined the HE improvement achieved via low-temperature soaking (150 °C). To this end, changes in the microstructures of both the steel matrix and sheared edge were analyzed, and various mechanical properties were evaluated before and after soaking. In addition, the HE resistances of the steel and sheared edges were evaluated using slow-strain-rate tensile and immersion tests, respectively. Before soaking, the CP microstructure comprised of tempered martensite and lath bainite with island-shaped polygonal bainite. After soaking, the overall microstructure remained largely unchanged, the yield strength and fracture toughness increased, and uniform localized nanohardness was achieved through carbon redistribution. The intrinsic resistance to HE is enhanced by carbon clustering or carbide precipitation, which impedes hydrogen diffusion. Immersion tests revealed that HE occurred only in the sheared edge with a burr upward, indicating the cut-edge condition significantly affected HE susceptibility. H-induced cracks in the CP microstructure before soaking propagated along interfaces between the island bainite and the matrix, where stress concentration occurred because of large differences in nanohardness. After soaking, cracks penetrated the island bainite, suggesting a reduced stress concentration caused by the more uniform nanohardness across phases. Overall, soaking improved the HE resistance of the sheared edge by altering crack propagation behavior. The enhanced fracture toughness improved damage tolerance to pre-existing defects and enhanced the resistance to HE, along with reduced H diffusivity.

Effects of Low-Temperature Heat Treatment on Mong Hsu Rubies

Effects of Low-Temperature Heat Treatment on Mong Hsu Rubies

Effects of Low-Temperature Heat Treatment on Mechanical and Thermophysical Properties of Cu-10Sn Alloys Fabricated by Laser Powder Bed Fusion.

This study investigated the impact of low-temperature heat treatments on the mechanical and thermophysical properties of Cu-10Sn alloys fabricated by a laser powder bed fusion (LPBF) additive manufacturing (AM) process. The microstructure, phase structure, and mechanical and thermal properties of the LPBF Cu-10Sn samples were comparatively investigated under both the as-fabricated (AF) condition and after low-temperature heat treatments at 140, 180, 220, 260, and 300 °C. The results showed that the low-temperature heat treatments did not significantly affect the phase and grain structures of the Cu-10Sn alloys. Both pre- and post-treatment samples displayed consistent grain sizes, with no obvious X-ray diffraction angle shift for the α phase, indicating that atom diffusion of the Sn element is beyond the detection resolution of X-ray diffractometers (XRD). However, the 180 °C heat-treated sample exhibited the highest hardness, while the AF samples had the lowest hardness, which was most likely due to the generation of precipitates according to thermodynamics modeling. Heat-treated samples also displayed higher thermal diffusivity values than their AF counterpart. The AF sample had the longest lifetime of ~0.19 nanoseconds (ns) in the positron annihilation lifetime spectroscopy (PALS) test, indicating the presence of the most atomic-level defects.

Thermal Stability of Electrodeposited Fe-55wt%Ni Alloy and Effect of Low-Temperature Heat Treatment on Magnetic Properties

Electrodeposited nanocrystalline soft magnetic materials have emerged as one of the hottest research topics in the field of magnetic materials due to they are easy to implement in miniaturization, lightweight, and energy-saving of electronic devices. The thermal stability and grain growth process of electrodeposited Fe-55wt%Ni alloy were investigated. Results indicated that the grain growth was rapid at a temperature of about 678 K, while the exothermic peak appeared in DSC with an exothermic heat of about 12 ± 1 J g−1. The activation energy for grain growth was obtained through the optimized Kissinger equation and isothermal kinetics calculations, and the growth mechanism was evaluated based on the calculation results. Below 678 K, the activation energy required for grain growth was low, which implied the growth mechanism was the rearrangement of atoms at the grain boundary; Above 678 K, the growth mechanism was grain boundary diffusion. After the low-temperature heat treatment, the coercivity (H c) decreased and the saturation magnetization (M s) increased slightly, which was attributed to the reduction of internal stress and the ultra-fine nanocrystalline structure. The optimal heat treatment process was 573 K heat treatment for 5 h, where M s and H c of 160 emu g−1 and below 1 Oe, respectively.

Improvement of mechanical properties of Co–Cr–W–Ni alloy tube suitable for balloon-expandable stent applications through heat treatment

This study focuses on the changes in the microstructure and mechanical properties of the Co–20Cr–15W–10Ni (CCWN, mass%) alloy tube, which, with heat treatment, is used as a balloon-expandable stent. To the best of our knowledge, this is the first report on the improvement of mechanical properties by microstructure control in CCWN alloy tubes. In addition, optimized heat treatment conditions are proposed for the development of next-generation small-diameter stents. The cold-worked CCWN alloy tube for stents was statically recrystallized by heat treatment at temperatures of 1373–1473 K for holding times of 60–900 s. The recrystallized alloy tubes exhibited a microstructure with a γ(fcc)-phase matrix and an average grain size of 5.8–34.1 μm. The strength and plastic elongation increased with decreasing grain size. In the coarse-grained structure, a large plate-like ε-phase formed along the twin boundary and stacking fault. The ε-phase grew to the grain boundaries, such that large cracks could form, resulting in early fracture. In the fine-grained structure, a small ε-phase formed by strain-induced martensitic transformation was uniformly dispersed, and the formation of large cracks was suppressed, leading to high ductility. The effect of low-temperature heat treatment (LTHT) at 873 K after recrystallization depended on the grain size of the alloy tube. In the alloy tube with a grain size of >15 μm, ε(hcp)-phase formation during plastic deformation was suppressed through the decrease in stacking fault density during LTHT, which resulted in improved ductility. In contrast, in the alloy tube with a grain size of <15 μm, the amount of precipitates increased during LTHT, resulting in reduced ductility.

Effect of low-temperature annealing on the superelastic response and electrochemical corrosion behaviour of equi-atomic Ni-Ti alloy

ABSTRACT Nickel–Titanium (Ni–Ti) alloys have exemplary properties such as good thermo-mechanical response and biocompatibility. Hence, they are one of the prime materials of interest in today’s context for the fabrication of advanced biomedical devices. Such properties can be exemplified with certain techniques such as heat-treatment techniques. However, peer-reviewed literature for the same appears to be inadequate to efficiently quantify the effect of such techniques on the overall performance of such materials. Therefore, the present study focuses on analysing the effect of low-temperature heat treatment on the superelastic behaviour and corrosion resistance of titanium-rich Ni–Ti alloys. The superelastic behaviour has been evaluated for different strains. Meanwhile, the Tafel extrapolation method is incorporated to assess the electrochemical corrosion of these materials. It is noticed that the low-temperature heat treatment has marginal effects on the superelastic behaviour of the alloy. The Ni–Ti alloy annealed at 450°C at 6% predetermined strain rate showed the best enhancement in the superelastic behaviour and the corrosion resistance increased upto treatment temperatures of 350°C. Therefore, the most optimum temperature of annealing is found to be 350°C, resulting in about 35.72% improvement in the corrosion resistance of the alloy when compared to their untreated counterparts.

Изменение цветовых характеристик кулинарных изделий из мяса индейки, изготовленных с применением низкотемпературной тепловой обработки

The paper presents the results of the study on the effect of low-temperature heat treatment on color characteristics and protein oxidation products depending on the method, temperature and duration of heat treatment of culinary products from turkey meat. At present, the use of low-temperature processing in the production technology for meat products with improved organoleptic indices is a topical direction.

Effect of Low-Temperature Heat Treatment on PM2.5 Adsorption Properties of GO Films

To explore the mechanism of GO acting on PM[Formula: see text], a graphene oxide (GO) film was prepared via a spraying method for air purification. The effects of different media, temperature and heat treatment times on the adsorption of PM[Formula: see text] on GO film were investigated. The morphology, composition and structure of GO materials were characterized by scanning electron microscopy (SEM), electron spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FT-IR) and Raman spectroscopy. When the vacuum heat-treatment temperature is below 80∘C and the atmospheric heat-treatment temperature is below 100∘C, the air purification performance of the film does not change significantly. With the increase in the vacuum heat-treatment temperature, the removal efficiency of PM[Formula: see text] by GO film decreases gradually from 95% to 83%. At different times, the vacuum heat treatment increases with time, and the film removal rate shows a downward trend. As the heat-treatment temperature and time increase, a certain redox reaction occurs in the GO, and the air purification performance decreases. At a temperature of 120∘C and a time of 8[Formula: see text]h, the removal rate drops to 81.68%. The adsorption of PM[Formula: see text] by GO film mainly relies on the action of oxygen-containing functional groups.

The Effect of Low-Temperature Heat Treatment on the Superelasticity in Ti–50.6 at % Ni Single Crystals

As a result of low-temperature aging at 573 K for 1.5 h of Ti–50.6 at% Ni [001]-oriented single crystals quenched from 1253 K, a high-strength state is obtained due to the precipitation of Ti3Ni4 nanoscale particles (d < 10 nm). The aging leads to the development of the B2–B19' martensitic transformation through an intermediate R phase, a reduction in the B19' martensite formation temperatures by 40–60 K, an increase in the strength properties of the B2 phase from 730 to 2100 MPa, and an extension of the superelasticity interval ΔTSE in compression from ΔTSE = 60 to 170 K (compared to quenched crystals).

Effects of thermal annealing on microstructure and magnetic properties of electrodeposited Co-Fe alloys

Thermal annealing could potentially serve as important instrument for controlling and improving the properties of the soft magnetic films. A systematic investigation is carried out in this study to determine and analyze the effects of low-temperature heat treatment on the microstructure and magnetic properties of CoFe films of different chemical compositions. The coercivity of the alloys is found to be critically influenced by surface roughness and uniaxial anisotropy, which is in turn affected by thermal annealing. The saturation magnetization on the other hand is controlled mainly by chemical compositions.

The effect of low-temperature heat treatment on the magnetic properties of biogenic ferrihydrite nanoparticles

We have studied the influence of low-temperature heat treatment (annealing) on the magnetic properties of superparamagnetic nanoparticles of biogenic ferrihydrite. It is established that the proposed treatment leads to an increase in the blocking temperature and magnetic susceptibility of samples. After subsequent exposure in aqueous medium, the magnetic properties of annealed sol remain constant. The character of changes in the magnetic properties of samples studied shows that low-temperature heat treatment allows nanoparticle dimensions to be increased in a controlled way.

Al&amp;ndash;Fe&amp;ndash;Mn合金箔の硬化現象に及ぼす低温熱処理の影響

Al&amp;ndash;Fe&amp;ndash;Mn合金箔の硬化現象に及ぼす低温熱処理の影響

Effect of low-temperature heat treatment and subsequent re-shot peening on surface characteristics and fatigue limit of shot-peened carbon steel

Effect of low-temperature heat treatment and subsequent re-shot peening on surface characteristics and fatigue limit of shot-peened carbon steel

Effect of low-temperature heat treatment on the physical properties of orthodontic wire: By Edward A. Kemler, D. D. S., Northwestern University Dental School, Chicago, Ill.

Effect of low-temperature heat treatment on the physical properties of orthodontic wire: By Edward A. Kemler, D. D. S., Northwestern University Dental School, Chicago, Ill.