Influence Of Heat Treatment Conditions Research Articles

Selective laser melting of AlSi10Mg alloy: influence of heat treatment condition on mechanical properties and microstructure

AlSi10Mg is the Al alloy most applied for selective laser melting (SLM) processing studies. The characteristics and the density obtained for SLM-processed material is extremely influenced by the quality of the starting powder. Since the microstructure obtained after SLM is often metastable, the required heat treatment to obtain an “optimized” microstructure can be significantly different than the one applied to conventionally cast or wrought Al alloys. In the present work, different thermal treatments have been applied to samples manufactured by SLM in order to investigate the effect on the microstructure and mechanical properties. The microstructural evaluation has been performed by SEM analysis and the mechanical properties have been determined by hardness measurements and tensile tests. Samples in the as-built condition, after stress relieving and under T6 heat treatment have been investigated to determine the best combination of properties.

Influence of Heat Treatment Conditions on the Magnetoresistive Properties of Three-layer Structures Fe0,2Co0,8/Cu/Fe0,2Co0,8

Influence of Heat Treatment Conditions on the Magnetoresistive Properties of Three-layer Structures Fe0,2Co0,8/Cu/Fe0,2Co0,8

Influence of heat treatment conditions on the mechanical properties of Ti–6Al–4V alloy

ABSTRACTIn the current work, several heat treatments were carried out below and above the beta-transition temperature of the Ti–6Al–4V alloy followed by aging at 550 °C for 6 hours. The resultant microstructures and their effects on the mechanical properties of Ti–6Al–4V alloy were investigated. The results showed that solution treatment of Ti–6Al–4V samples followed by water quenching from β and α/β fields raised the alloy hardness from 380 to 575 and 656 HV, respectively, while no remarkable changes were observed after aging. The hot tensile strength of the as-forged sample increased from 671 to 756 MPa after water quenching from the ß- or α/ß- field, while the air cooling from β-phase field decreased the tensile strength to 644 MPa. The fracture mode of the tensile samples was more ductile in case of the solution-treated samples compared to the as-forged samples. A subsurface layer was formed due to the diffusion of oxygen into the surface at high temperatures. This layer which is known as ‘oxygen diffusion layer’ masked the differences of wear behaviour of the specimens.

Influence of heat treatment conditions on bending characteristics of 6063 aluminum alloy sheets

Bending deformation behaviors of solution treated (ST), natural aged (NA) and T6 tempered 6063 aluminum alloy sheets were studied by three-point bending tests. The changes of bending force, interior angle, bending radius and sheet thickness in the fillet region were analyzed by experimental measurements and numerical simulations. The results showed that the bending characteristics were strongly dependent on the heat treatment conditions. The T6 alloy sheets were bent more sharply and local plastic deformation occurred severely in the fillet region. However, the ST and NA alloy sheets exhibited relatively uniform bending deformation and large bending radius. The bending force of T6 alloy was the highest, followed by the NA alloy and that of the ST alloy was minimum. After unloading, as compared with the ST and NA alloys, the springback of T6 alloys was markedly larger. The aging time showed a positive sensitivity on the springback and non-uniform bending deformability. The bending characteristics are attributed to the combined effects of yield strength, yield ratio and coefficient of neutral layer.

The influence of heat treatment conditions on the structure and properties of (As<sub>2</sub>Se<sub>3</sub>)<sub>100-x</sub>(SbSI)<sub>x</sub> glasses and composites on their basis

Приведені результати термографічних та рентгеноструктурних досліджень стекол і композитів в системі As 2 Se 3 -SbSI. Встановлено, що кристалізація стекол відбувається в декілька етапів і супроводжується аномаліями на температурних залежностях діелектричних параметрів. Структура фази, яка виникає в скляній матриці при низькотемпературному відпалі (393-453 К), відповідає структурі кристалічного сульфойодиду сурми. Визначена природа кристалічних включень, які формуються в структурній сітці в умовах високотемпературного відпалу.

ИССЛЕДОВАНИЕ ВЛИЯНИЯ РЕЖИМОВ ТЕРМИЧЕСКОЙ ОБРАБОТКИ НА СТРУКТУРУ И СВОЙСТВА ОПЫТНЫХ ПОКОВОК ИЗ СПЛАВА ВТ41 С МЕЛКОЗЕРНИСТОЙ СТРУКТУРОЙ

ИССЛЕДОВАНИЕ ВЛИЯНИЯ РЕЖИМОВ ТЕРМИЧЕСКОЙ ОБРАБОТКИ НА СТРУКТУРУ И СВОЙСТВА ОПЫТНЫХ ПОКОВОК ИЗ СПЛАВА ВТ41 С МЕЛКОЗЕРНИСТОЙ СТРУКТУРОЙ

Influence of heat treatment process on photocatalytic activity of photocatalyst TiO2/TiCxOy coatings during heat treatment in carbon powder

Photocatalyst TiO2/TiCxOy coatings on alumina (Al2O3) balls had been successfully fabricated by mechanical coating technique with titanium (Ti) powder and subsequent heat treatment in carbon powder. The influence of heat treatment conditions in carbon powder on the formed compounds, surface morphology and photocatalytic activity of photocatalyst TiO2/TiCxOy coatings was investigated. XRD results show that the compounds of TiCxOy and TiO2 were formed on the surface of Ti coatings during heat treatment in carbon powder. The relative amounts of TiCxOy and TiO2 remarkably varies with changing the heat treatment temperature and/or holding time. The formed nano-bump structure during heat treatment in carbon powder at 1073 or 1173 K, could increase the accessible surface area. The formation of Ti3+ and generated oxygen vacancies confirmed by XPS measurement, are in favor of narrowing band gap to enhance the visible-light photocatalytic activity of photocatalyst TiO2/TiCxOy coatings. The photocatalytic activity of the sample by heat treatment in carbon powder at 1173 K for 15 h shows highest. The fabrication strategy provides us a facile preparation procedure of visible-light responsive photocatalyst coatings.

Influence of Heat Treatment Conditions on the Properties of Vanadium Oxide Thin Films for Thermochromic Applications.

In present work, the effects of the heat treatment on the structural, optical, and thermochromic properties of vanadium oxide films were investigated. Vanadium dioxide (VO2) thin films were deposited on glass substrate by reactive pulsed DC magnetron sputtering from a vanadium metal target in mixture atmosphere of argon and oxygen gas. Various heat treatment conditions were applied in order to evaluate their influence on the crystal phases formed, surface morphology, and optical properties. The films were characterized by an X-ray diffraction (XRD) in order to investigate the crystal structure and identify the phase change as post-annealing temperature of 500-600 degrees C for 5 minutes. Surface conditions of the obtained VO2(M) films were analyzed by field emission scanning electron microscopy (FE-SEM) and the semiconductor-metal transition (SMT) characteristics of the VO2 films were evaluate by optical spectrophotometry in the UV-VIS-NIR, controlling temperature of the films.

Influence of Heat Treatment Condition for the Grain Boundary Serration on Deformation Behavior of Alloy 617 during Creep at 950℃

Influence of Heat Treatment Condition for the Grain Boundary Serration on Deformation Behavior of Alloy 617 during Creep at 950℃

Effect of Aging Time to the Commercial Aluminum Alloy Modified with Zirconium Addition

The influence of heat treatment condition with addition of zirconium on the some properties of aluminum alloy has been investigated. The composition of aluminum alloy cast produce from this research was supplied from the foundry. The cast alloys were given a solutionizing treatment at 520°C followed by artificial aging at 175°C for a different period of time up to 10 hours. Hardness of heat treated aluminum alloy then were determined by comparing to the as cast and natural aging alloy. The addition of zirconium will improve the properties of the alloy in term of hardness and conductivity. Grain size of alloy has no significant effect when aging time increased together with zirconium addition.

Influence of Heat Treatment Conditions on Properties of High-Speed P/M Steel Vanadis 30

The high-speed P/M steel Vanadis 30 was austenitized at 1100 °C, quenched and tempered at various combinations of processing parameters. For one set of specimens, also sub-zero period, made at -196 °C/4 hours between quenching and tempering. The microstructure and mechanical properties have been investigated as a function of austenitizing time, parameters of sub-zero processing and tempering. There were used metallographic analysis, hardness measurement and three point bending test for the evaluation effect of heat treatment conditions to observed materials.

Influence of Heat Treatment Conditions on Microstructure and Mechanical Properties of Austempered Ductile Iron After Dynamic Deformation Test

Abstract In this article, an attempt was made to determine the effect of dynamic load on the austempered ductile iron resistance obtained under different conditions of heat treatment. Tests were carried out on six types of cylindrical ductile iron samples austempered at 320, 370 and 400oC for 30 and 180 minutes. For each type of material, two samples were collected. As a next step in the investigations, the samples were subjected to a Taylor impact test. The samples after striking a non-deformable, rigid target were deformed on their front face. After Taylor test, a series of material tests was performed on these samples, noting a significant increase of hardness in the deformed part. This was particularly well visible in the ductile iron isothermally quenched at higher temperatures of 370 and 400oC. Inthezone of sample deformation, an increase in the content of ferromagnetic phase was also reported, thus indicating the occurrence of martensitic transformation in the microstructure containing mechanically unstable austenite. A significant amount of deformed graphite was also observed, which was a symptom of the deformation process taking place in samples. The ductile iron was characterized by high toughness and high resistance to the effect of dynamic loads, especially as regards the grade treated at a temperature of 370oC.

Influence of Heat Treatment Process on the Acceptability of Pasteurized Beetroot

Abstract: A heat-treated beet is defined as a food that is subject to a temperature, high enough to destroy microorganisms and to preserve all the nutrients. The aim of the study presented in this paper was to investigate the effect by cooking on the properties of heat threated beetroot in the temperature range between 75 °C and 115 °C during the 40, 50 and 60 minutes of cooking. In order to determine the optimal conditions for the implementation of various heat treatment procedures consequently, was followed the influence of heat treatment conditions (temperature/time) on the composition, rheological properties, pH, color change (L*, a*, b*) and sensory characteristics during the development of the “pasteurized/sterilized” beet product. This study has shown that the optimum time and temperature for processing of beetroot is 105 °C at 50 minutes. Samples of beetroot, processed under these conditions had the best softness, the most acceptable taste and color (sensory and instrumentally determined).

Optimal Conditions for Preparing Sintered Glass-Ceramics with Glass Frit from a Waste Water Flocculate

Sintered glass-ceramics have been successfully prepared using glass particles derived from a waste water flocculate. Influence of heat treatment conditions (sintering temperature and soaking time, heating rate) and size of the glass particles on the microstructure and density, hardness of the obtained glass-ceramics has been studied. The results show that the prepared glass-ceramics have gehlenite and anorthite as main crystalline phases. SEM analysis indicates that the size and morphology of the crystallites vary with the preparation conditions. A dense glass-ceramic with a high hardness can be obtained by sintering glass powder sized smaller than 0.075mm with a relatively slow ramping rate (3°C/min) to a temperature higher than the crystallization peak temperature of the parent glass for a short period of 30min to 1h.

無電解Ni-P/SiC複合めっき皮膜の熱処理条件が摩擦係数に与える影響

無電解Ni-P/SiC複合めっき皮膜の熱処理条件が摩擦係数に与える影響

Influence of heat treatment conditions on the structure of hollow carbon fibers prepared from solid PVA fibers using iodine pretreatment

The influence of heating conditions on the structure of hollow carbon fibers (H-CFs) during their fabrication from solid poly(vinyl alcohol) (PVA) fibers is reported. The hollow structure of PVA-derived carbon was formed by selective iodination and subsequent stabilization of precursor PVA fiber close to the fiber surface followed by carbonization. The broadening of X-ray diffraction peaks due to disorder and the small size effects of the (002) plane were strongly reduced by increasing the heat treatment temperature (HTT) from 800 to 3000 °C, but the asymmetric shape of (10) and (110) reflections suggests turbostratic layer stacking. The increase of HTT to 3000 °C increased the degree of graphitization evident from the decrease of interplanar spacing from 0.360 to 0.338 nm and the intensity ratio of D to G bands in Raman spectra from 0.93 to 0.58. The crystallite size, orientation and electrical conductivity of the resultant H-CFs were also improved with higher HTT. Besides, the size of the hollow core was also influenced by the HTT and both wall thickness and carbon yield decreased with higher HTT. The core of the H-CFs could be easily filled with polymer by bulk polymerization of monomer.

Investigation on the Solution-Based Metal-Oxide Semiconductor Film and its Properties

In this paper, the ZrInZnO thin film has been prepared by solution method. The influence of heat treatment conditions on film properties has been analyzed. With the treatment temperature and time increase, the Hall mobility and square resistance of the film were increased and reduced respectively. In addition, we analyzed the role of heavy metal Zr on oxygen vacancies in the semiconductor oxide combined with heat treatment results and the chemical reaction process. It has been found that heavy metal Zr has binding effect on oxygen, it effectively inhibits the generation of oxygen vacancies, thereby reducing the number of oxygen vacancies, but at the same time causing certain binding effect to carriers.

High Cycle Fatigue of Cast Mg-3Nd-0.2Zn Magnesium Alloys

This paper investigates the high cycle fatigue properties of a recently developed high-strength cast magnesium alloy [Mg-3Nd-0.2Zn (all compositions in wt pct except when otherwise stated)] with varied Zr contents for grain refinement (NZ30K) and the influence of heat treatment conditions. The NZ30K alloy containing 0.45Zr and heat treated to the peak-aged T6 condition [14 hours at 473 K (200 °C)] shows the highest fatigue strength, about 100 MPa, which is about 25 pct higher than that of commercial AZ91D-T6 alloy. In the absence of casting flaws, the high cycle fatigue properties of the NZ30K alloy strongly depend on its grain size and heat treatment conditions. The dependency of fatigue strength on grain sizes follows the Hall–Petch relationship. The NZ30K alloy also shows a significant response to heat treatments. The fatigue strength increases in a near linear fashion with increasing yield strength of the material through heat treatment.

Preliminary Evaluation of the Thermally Affected Metallurgical Condition of Extruded and Drawn CuFe2P Tubes

The influence of heat treatment conditions on the mechanical behavior and microstructure of CuFe2P (ASTM C19400) in comparison to deoxidized-high-phosphorus (DHP-Cu/ASTM C12200) tubes was investigated. The aim of this study was the enhancement of understanding of microstructure/thermal treatment/strength relationships which could be further utilized for the manufacturing of components exhibiting superior performance and reliability for refrigeration and heat exchanger applications. Microstructural examination employing optical metallography and scanning electron microscopy is used for the evaluation of the recrystallization progress and grain growth processes. In addition, tensile testing was conducted to CuFe2P and DHP tubes following the application of heat treatment cycles, in accordance to the EN 10002-1 specifications. Mechanical properties and microstructure evaluation showed that CuFe2P material is fully recrystallized at 740 °C and DHP at 400 °C for 20 min. Recrystallization initiation varies within the range of 640-660 °C for CuFe2P and below 400 °C for DHP tubes. The tensile strength of the CuFe2P tube decreased from 513 to 367 MPa, the hardness was reduced from 144 to 126 HV, while tensile elongation was significantly improved from 3 to 17%. At 640 °C, only isolated recrystallized areas were evident mainly at the Fe-based intermetallic particle/copper matrix interface areas.

Influence of the Heat Treatment Condition upon the High-Speed Cutting Mechanism of Aluminum Alloy A2017

This paper discusses the influence of heat treatment condition of aluminum alloy upon cutting mechanism. The orthogonal cutting experiments of A2017-T3 and A2017-O with a cutting speed of from 0.5 m/s to 160 m/s are conducted. The experiments obtain the following results: A2017-T3 forms discontinuous and serrated chip, while A2017-O forms continuous flow-type chip, regardless of cutting speed. The tendencies of the changes in shear angle, cutting forces, friction angle and the shear stress on the shear plane with the cutting speed are the same between A2017-T3 and A2017-O, when the cutting speed is less than 80 m/s. The significant dissimilarities in the cutting mechanism, however, between A2017-T3 and A2017-O come to appear gradually, when the cutting speed exceeds 80 m/s. For A2017-T3, the shear stress on the shear plane is steady, and the friction angle at the tool-chip interface increases slightly in such a high-speed cutting condition. In contrast, for A2017-O, the shear stress on the shear plane rises gradually, while the friction angle keeps decreasing with the cutting speed. An analysis based on the simple shear model shows that the shear strain rate at the shear zone reaches up to 107 1/s when the cutting speed is beyond 80 m/s. The appearance of these dissimilarities in the cutting mechanism due to the difference in the heat treatment conditions will depend on the characteristics of dynamic plastic behavior and dynamic friction property of aluminum alloy appearing at high-strain-rate fields.