Reaction Routes of CaO–Fe2O3–TiO2 and Calcium Ferrite–TiO2 System in Continuous Heating Process

2018 ◽  
pp. 159-165 ◽  
Author(s):  
Chengyi Ding ◽  
Xuewei Lv ◽  
Gang Li ◽  
Chenguang Bai ◽  
Senwei Xuan ◽  
...  
Keyword(s):  
Calcium Ferrite ◽  
Continuous Heating ◽  
Heating Process ◽  
Reaction Routes

scholarly journals Plasmon-Enhanced Photothermal and Optomechanical Deformations of a Gold Nanoparticle

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1881
Author(s):  
Jiunn-Woei Liaw ◽  
Guanting Liu ◽  
Yun-Cheng Ku ◽  
Mao-Kuen Kuo
Keyword(s):  
Gold Nanoparticle ◽  
Liquid Layer ◽  
Viscoelastic Model ◽  
Dynamics Simulation ◽  
Photothermal Effect ◽  
Continuous Heating ◽  
Heating Process ◽  
Elastic Model ◽  
Linearly Polarized ◽  
Quasi Liquid Layer

Plasmon-enhanced photothermal and optomechanical effects on deforming and reshaping a gold nanoparticle (NP) are studied theoretically. A previous paper (Wang and Ding, ACS Nano 13, 32–37, 2019) has shown that a spherical gold nanoparticle (NP) irradiated by a tightly focused laser beam can be deformed into an elongated nanorod (NR) and even chopped in half (a dimer). The mechanism is supposed to be caused by photothermal heating for softening NP associated with optical traction for follow-up deformation. In this paper, our study focuses on deformation induced by Maxwell’s stress provided by a linearly polarized Gaussian beam upon the surface of a thermal-softened NP/NR. We use an elastic model to numerically calculate deformation according to optical traction and a viscoelastic model to theoretically estimate the following creep (elongation) as temperature nears the melting point. Our results indicate that a stretching traction at the two ends of the NP/NR causes elongation and a pinching traction at the middle causes a dent. Hence, a bigger NP can be elongated and then cut into two pieces (a dimer) at the dent due to the optomechanical effect. As the continuous heating process induces premelting of NPs, a quasi-liquid layer is formed first and then an outer liquid layer is induced due to reduction of surface energy, which was predicted by previous works of molecular dynamics simulation. Subsequently, we use the Young–Laplace model to investigate the surface tension effect on the following deformation. This study may provide an insight into utilizing the photothermal effect associated with optomechanical manipulation to tailor gold nanostructures.

scholarly journals Investigation of phase transformation in Fe microalloyed Ti6Al4V alloy during continuous heating process

2020 ◽  
Vol 321 ◽  
pp. 12010
Author(s):  
Changliang Wang ◽  
Feng Li ◽  
Can Ding ◽  
Hui Chang ◽  
Lian Zhou
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Expansion Method ◽  
Ti6al4v Alloy ◽  
Continuous Heating ◽  
Heating Process ◽  
Β Phase ◽  
Α Phase ◽  
Phase Transition Temperatures ◽  
Evolution Of Microstructure

The phase transformation and dilatometric curves in Fe microalloyed Ti6Al4V alloy (Ti6Al4V-Fe) during continuous heating at 1 ℃ /min heating rate had been studied by dilatometer and metallographic methods, and β phase transition temperatures of alloy were obtained. In order to validate the accuracy of these β phase transition temperature and microstructure evolution, the relative phase concentration and the evolution of microstructure which were acquired by cooling after tempering were analyzed by metallographic microscope. The results illuminated that the expansion method was able to accurately measure the β transformation temperature of Ti6Al4V-Fe alloy. The lathy-shaped α phase decreased significantly disappeared in the range of 838℃ to 988℃, and the α→β phase transformation occurred.

scholarly journals Prediction of microstructure composition in steel plate heated using high power Yb:YAG laser radiation

2019 ◽  
Vol 254 ◽  
pp. 02023
Author(s):  
Marcin Kubiak
Keyword(s):  
Heat Transfer ◽  
Phase Transformations ◽  
Steel Plate ◽  
Navier Stokes ◽  
Continuous Heating ◽  
Heating Process ◽  
Navier Stokes Equation ◽  
Coupled Heat Transfer ◽  
Laser Head ◽  
Kinetics Of

This work concerns numerical modelling and computer simulations of temperature field and phase transformations during Yb:YAG laser heating of sheets made of S355 steel. The distribution of laser power emitted by Trumpf laser head D70 is used in the analysis. The heat source is modelled on the basis of interpolation algorithms using geostatistical kriging method. Coupled heat transfer and fluid flow in the fusion zone are described respectively by transient heat transfer equation with convective term and Navier-Stokes equation. The kinetics of phase transformations and volumetric fractions of arising phases are obtained on the basis of Johnson-Mehl-Avrami (JMA) and Koistinen-Marburger (KM) models. Continuous Heating Transformation (CHT) diagram is used for heating process and Continuous Cooling Transformation (CCT) diagram is used for heated steel with the decomposition of final volume fractions of phases transformed form austenite dependant on cooling rates.

In-situ investigation on the structural evolution of mesomorphic isotactic polypropylene in a continuous heating process

Polymer ◽  
2016 ◽  
Vol 105 ◽  
pp. 133-143 ◽  
Author(s):  
Qianhong Jiang ◽  
Ying Zhao ◽  
Chunbo Zhang ◽  
Jian Yang ◽  
Yizhuang Xu ◽  
...  
Keyword(s):  
Isotactic Polypropylene ◽  
Structural Evolution ◽  
Continuous Heating ◽  
Heating Process ◽  
In Situ Investigation

scholarly journals Influence of Heat-Treatment on Enhancement of Yield Strength and Hardness by Ti-V-Nb Alloying in High-Manganese Austenitic Steel

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 299 ◽  
Author(s):  
Zaifeng Zhou ◽  
Zhexuan Zhang ◽  
Quan Shan ◽  
Zulai Li ◽  
Yehua Jiang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Impact Toughness ◽  
Yield Strength ◽  
Austenitic Steel ◽  
Brinell Hardness ◽  
Strengthening Mechanism ◽  
Continuous Heating ◽  
Heating Process ◽  
High Manganese ◽  
High Manganese Austenitic Steel

To deal with the problem of poor yield strength and hardness in the initial use of high-manganese austenitic steel, we investigated the alloying design, microstructure, precipitates, mechanical properties, and comprehensive strengthening mechanism of high-manganese austenitic steel through two novel heat-treatment processes, namely continuous heating process (CHP) and segmented heat preservation process (SHPP). In this work, austenitic Fe-0.9C-17Mn-0.8Si-2.0Cr-0.3Ni-0.5Cu-0.7Mo steels alloyed with Ti, V, and Nb were designed. The grain size of SHPP steels was smaller than that of CHP steels due to the smaller size of precipitates. The results of mechanical experiments showed that the yield strength and impact toughness of SHPP steel were obviously higher than those of CHP steel, but the Brinell hardness of CHP steel was higher than that of SHPP steel. The higher Brinell hardness and poorer impact toughness of CHP steel were mainly due to the larger-sized precipitates. Finally, solid-solution strengthening played the most effective role of increasing the yield and tensile strengths of the two steels.

Effect of Continuous Heating on Grain Growth in Fe-40Ni-Ti Alloy

2014 ◽  
Vol 988 ◽  
pp. 151-155
Author(s):  
Shao Qiang Yuan ◽  
Yue Hui Yang ◽  
Zhen Liang Wang
Keyword(s):  
Mathematical Model ◽  
Grain Size ◽  
Grain Growth ◽  
Experimental Results ◽  
Continuous Heating ◽  
Heating Process ◽  
Ti Alloy ◽  
Size Growth ◽  
Metallographic Observation ◽  
The Mathematical Model

The grain growth of Fe-40Ni-Ti alloy was investigated by means of metallographic observation during continuous heating. The experimental results indicate that: the microstructures consist of multi-polygon austenite. No transformation happens of tested alloy during heating only the grain size increases gradually. The size of grain grows steadily below 1160°C until 1200°C, the grain size growth unusually. The process of grain growth has relations with the dissolving of TiN particles. Finally, the mathematical model of grain growth in continuous heating process was obtained for the tested alloy.

scholarly journals Precipitation behaviour during the β → α/ω phase transformation and its effect on the mechanical performance of a Ti-15Mo-2.7Nb-3Al-0.2Si alloy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tiewei Xu ◽  
Shanshan Zhang ◽  
Sen Liang ◽  
Ning Cui ◽  
Lei Cao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transformation ◽  
Tensile Properties ◽  
Mechanical Performance ◽  
Continuous Heating ◽  
Precipitation Process ◽  
Heating Process ◽  
Ω Phase ◽  
Precipitation Behaviour ◽  
Different Temperatures

AbstractThe activation energy of the β → α/ω phase transformation increased monotonously with the application of a continuous heating process to a Ti-15Mo-2.7Nb-3Al-0.2Si alloy. Precipitation behaviour of the alloy aged at different temperatures were analysed with scanning electron microscopy, electron backscattered diffraction and transmission electron microscopy. Selected-area diffraction patterns of the ω, ω/α and α phases in the alloy aged at different temperatures indicated that the type of phase transformation was influenced by the precipitation process. Precipitate-free zones in the alloy aged at 450 °C for 8 h were harmful to the mechanical performance. Fine α precipitates with an obvious texture were obtained in the alloy aged at 500 °C. A good combination of tensile properties with an ultimate tensile strength of 1310 MPa and an elongation of 13.5% were obtained due to the expected microstructure and texture of the precipitates that transformed in the specimen when it was aged at 500 °C for 8 h. The size of the precipitates increased with increasing aging temperature. Furthermore, the amount of precipitates and their degree of texture decreased substantially in the alloy aged at 600 °C. The investigation of the tensile properties and fractures also revealed a correlation between the mechanical properties and precipitation behaviour in the Ti-15Mo-2.7Nb-3Al-0.2Si alloy aged at different temperatures.

Microstructure Evolution of Deformed Magnesium Alloy in Semi-Solid State

2005 ◽  
Vol 488-489 ◽  
pp. 313-316
Author(s):  
Sen Yuan ◽  
Wu Xiao Wang ◽  
Bai Ling Jiang
Keyword(s):  
Solid State ◽  
Magnesium Alloy ◽  
Microstructure Evolution ◽  
High Energy ◽  
Mg Alloy ◽  
Continuous Heating ◽  
Heating Process ◽  
Semisolid State ◽  
Semi Solid ◽  
Temperature Time

Magnesium alloy slurry was prepared using Strain-Induced Melt Activation(SIMA) technique. The samples were quenched into water so as to fix the high temperature instantaneous microstructures. The microstructure evolution of compressed deformation Mg alloy is studied in the process of continuous heating and iso-temperature of semi-solid state. The results indicate that deformed Mg alloy (AZ91) has first occurred to have the conversion of dendrite crystal-oriented isometric crystals in the continuous heating process. When the temperature rises to the range of semisolid state, the region with high energy at the pressed stripes begins to melt, showing that the cellular structures emerge in the crystal boundary and melting micro-pool phenomena appear within the crystals. With the iso-temperature time in semisolid state prolongs, the isometric crystals can be gradually converted into spherical crystal grains.

scholarly journals Molecular Dynamics Study on Structural and Atomic Evolution Between Au and Ni Nanoparticles Through Coalescence

2021 ◽  
Author(s):  
Bangquan Li ◽  
Jing Li ◽  
Xiaoqiang Su ◽  
Yimin Cui
Keyword(s):  
Molecular Dynamics ◽  
Md Simulations ◽  
Thermal Control ◽  
Structure Evolution ◽  
Continuous Heating ◽  
Heating Process ◽  
Au Nps ◽  
Atomic Segregation ◽  
Spherical Structures ◽  
Increasing Temperature

Abstract Motivated by the structure evolution experiments of Janus NiAu nanoparticles (NPs), we present a detailed study on the thermodynamic evolution of Ni and Au NPs with different ratios of Au and Ni through the molecular dynamics (MD) simulations. It is found that, for fixed Ni particle size (5.8 nm in diameter), the energy variation with the increasing temperature is related to the Au sizes (1.5–9.6 nm in diameter), due to the diverse atomic segregation modes. For a small Au particle, due to lattice induction, the structure will change from order to disorder and then to order. The interface defects of the merging NPs could be automatically eliminated by coalescence processes. The change in energy as the temperature increases is similar to that of monometallic NPs. For larger Au particles, the irregular variation of energy occurs and the atomic energy experience one or two reductions with the increase of the temperature. The segregation of Au atoms to the surface of Ni particle is dominant during the continuous heating process. The coalescence processes of Au atoms strongly determine the final morphology of the particles. Dumbbell-like, Janus and eccentric core-shell spherical structures could be obtained during the heating process. Our results will provide an effective approach to the design of novel materials with specific properties through thermal control.

scholarly journals Molecular dynamics study on structural and atomic evolution between Au and Ni nanoparticles through coalescence

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bangquan Li ◽  
Jing Li ◽  
Xiaoqiang Su ◽  
Yimin Cui
Keyword(s):  
Molecular Dynamics ◽  
Md Simulations ◽  
Thermal Control ◽  
Structure Evolution ◽  
Continuous Heating ◽  
Heating Process ◽  
Au Nps ◽  
Atomic Segregation ◽  
Spherical Structures ◽  
Increasing Temperature

AbstractMotivated by the structure evolution experiments of Janus NiAu nanoparticles (NPs), we present a detailed study on the thermodynamic evolution of Ni and Au NPs with different ratios of Au and Ni through the molecular dynamics (MD) simulations. It is found that, for fixed Ni particle size (5.8 nm in diameter), the energy variation with the increasing temperature is related to the Au sizes (1.5–9.6 nm in diameter), due to the diverse atomic segregation modes. For a small Au particle, due to lattice induction, the structure will change from order to disorder and then to order. The interface defects of the merging NPs could be automatically eliminated by coalescence processes. The change in energy as the temperature increases is similar to that of monometallic NPs. For larger Au particles, the irregular variation of energy occurs and the atomic energy experience one or two reductions at least with the increase of the temperature. The segregation of Au atoms to the surface of Ni particle is dominant during the continuous heating process. The coalescence processes of Au atoms strongly determine the final morphology of the particles. Dumbbell-like, Janus and eccentric core–shell spherical structures could be obtained during the heating process. Our results will provide an effective approach to the design of novel materials with specific properties through thermal control.

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