The Grain Growth of Austenitic Model Steel during Fast Heating

2014 ◽  
Vol 644-650 ◽  
pp. 4772-4775
Author(s):  
Shao Qiang Yuan ◽  
Guo Li Liang ◽  
Yue Hui Yang
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Ti Alloy ◽  
Parent Metal ◽  
Simulation Test ◽  
Fast Heating ◽  
Metallographic Observation ◽  
Welding Line ◽  
Quantitative Statistics ◽  
Different Parts

The metallographic observation, thermo-simulation test and quantitative statistics were used to investigate the grain growth on different parts of the samples for Fe-40Ni-Ti alloy. The experiment results demonstrate that: near the center of the sample corresponding to the summit point of the temperature, the grain grows rapidly in 5s when the temperature reaches 1350°C, whose size is about 180μm; While the grain size of parent metal and HAZ (4mm to the welding line) remains nearly unchanged, whose size is about 80μm. The size of TiN particles in the welding line is fine than that of the parent metal obviously and the hinder to the grain boundaries can be observed. With the aid of Fe-40Ni-Ti alloy, the austenitic grain growth in the steel can be simulated.

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.

Eco-Friendly Grain Refinement for A3003 Alloy

2009 ◽  
Vol 620-622 ◽  
pp. 89-92
Author(s):  
Hoon Cho ◽  
Jae Hong Ha ◽  
Byoung Soo Lee ◽  
Sung Ho Chang ◽  
Je Sik Shin
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Grain Growth ◽  
Heterogeneous Nucleation ◽  
Aluminum Matrix ◽  
Graphite Crucible ◽  
Holding Time ◽  
Ti Alloy ◽  
Grain Refiner ◽  
Prolonged Holding

Eco-friendly grain refinement of A3003 alloy was studied by addition of non-toxic Al-Ti alloy because of toxic-fluorine in Al-Ti-B alloys which used as a representative grain refiner for aluminum and its alloys. TiAl3 phase in Al-Ti alloy bring to decrease grain size of A3003 alloy. But, grain growth occurred with prolonged holding time due to the solution of Ti into aluminum matrix. In contrast, lasting grain refinement of A3003 alloy was occurred in graphite crucible. It can be mentioned that carbon comes from graphite crucible was combined with Ti solute in aluminum melt and then TiC acts as a heterogeneous nucleation for A3003 alloy.

Annealing Phenomena in Cu/Ni Composite Electrodeposit

2012 ◽  
Vol 715-716 ◽  
pp. 952-952
Author(s):  
K.H. Kim ◽  
D.H. Kang ◽  
Yong Bum Park
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Abnormal Grain Growth ◽  
The Other ◽  
Atomic Diffusion ◽  
Copper Sheet ◽  
Interfacial Stresses ◽  
Mean Size ◽  
Electroplated Copper ◽  
Different Parts

Cu/Ni composite electrodeposit was fabricated by electroplating nickel on the both sides of an electroplated copper sheet. In order to lower interfacial stresses between copper and nickel, the microstructure of nickel was controlled to consist of grains with a mean size of 15 nanometers. The different parts of the composite electrodeposit underwent different evolution of textures and microstructures during annealing. In the Cu electrodeposit, the as-deposited texture characterized by a relatively high <100>//ND and twin components transformed to be diffuse due to grain growth during annealing above 300°C. This is attributed to a large number of twins conducting the as-deposited microstructure. On the other hand, in the Ni electrodeposit, grain growth that takes place during annealing above 250°C corresponds to abnormal grain growth in terms of the scale change of the grain size. This grain growth also transformed the as-deposited texture of strong <100>//ND into a diffuse texture. In the interface between copper and nickel, the atomic diffusion was generated by excessive vacancies resulting from the grain growth during the annealing of nanostructured Ni electrodeposit. An 'interface texture' began to developed in the previous Cu region above 500°C, and the microtexture development was similar to the growth texture of the annealed Ni electrodeposit.

scholarly journals Relevance of processing parameters for grain growth of metal halide perovskites with nanoimprint

2021 ◽  
Vol 127 (9) ◽  
Author(s):  
Andre Mayer ◽  
Tobias Haeger ◽  
Manuel Runkel ◽  
Johannes Rond ◽  
Johannes Staabs ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Secondary Growth ◽  
Processing Parameters ◽  
Post Processing ◽  
Perovskite Layer ◽  
Processing Step ◽  
Similar Preparation ◽  
Materials Used ◽  
Log Normal

AbstractThe quality and the stability of devices prepared from polycrystalline layers of organic–inorganic perovskites highly depend on the grain sizes prevailing. Tuning of the grain size is either done during layer preparation or in a post-processing step. Our investigation refers to thermal imprint as the post-processing step to induce grain growth in perovskite layers, offering the additional benefit of providing a flat surface for multi-layer devices. The material studied is MAPbBr3; we investigate grain growth at a pressure of 100 bar and temperatures of up to 150 °C, a temperature range where the pressurized stamp is beneficial to avoid thermal degradation. Grain coarsening develops in a self-similar way, featuring a log-normal grain size distribution; categories like ‘normal’ or ‘secondary’ growth are less applicable as the layers feature a preferential orientation already before imprint-induced grain growth. The experiments are simulated with a capillary-based growth law; the respective parameters are determined experimentally, with an activation energy of Q ≈ 0.3 eV. It turns out that with imprint as well the main parameter relevant to grain growth is temperature; to induce grain growth in MAPbBr3 within a reasonable processing time a temperature of 120 °C and beyond is advised. An analysis of the mechanical situation during imprint indicates a dominance of thermal stress. The minimization of elastic energy and surface energy together favours the development of grains with (100)-orientation in MaPbBr3 layers. Furthermore, the experiments indicate that the purity of the materials used for layer preparation is a major factor to achieve large grains; however, a diligent and always similar preparation of the layer is equally important as it defines the pureness of the resulting perovskite layer, intimately connected with its capability to grow. The results are not only of interest to assess the potential of a layer with respect to grain growth when specific temperatures and times are chosen; they also help to rate the long-term stability of a layer under temperature loading, e.g. during the operation of a device.

scholarly journals Mean Field Analysis of Orientation Selective Grain Growth Driven By Interface-Energy Anisotropy

1994 ◽  
Vol 343 ◽  
Author(s):  
J. A. Floro ◽  
C. V. Thompson
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Growth ◽  
Texture Evolution ◽  
Mean Field ◽  
Orientation Distribution ◽  
Interface Energy ◽  
Abnormal Grain Growth ◽  
Field Analysis ◽  
Energy Anisotropy

ABSTRACTAbnormal grain growth is characterized by the lack of a steady state grain size distribution. In extreme cases the size distribution becomes transiently bimodal, with a few grains growing much larger than the average size. This is known as secondary grain growth. In polycrystalline thin films, the surface energy γs and film/substrate interfacial energy γi vary with grain orientation, providing an orientation-selective driving force that can lead to abnormal grain growth. We employ a mean field analysis that incorporates the effect of interface energy anisotropy to predict the evolution of the grain size/orientation distribution. While abnormal grain growth and texture evolution always result when interface energy anisotropy is present, whether secondary grain growth occurs will depend sensitively on the details of the orientation dependence of γi.

The Effect of Grain Size on Superplastic Deformation of Ti-6Al-4V Alloy

2007 ◽  
Vol 551-552 ◽  
pp. 387-392 ◽  
Author(s):  
Wen Juan Zhao ◽  
Hua Ding ◽  
D. Song ◽  
F.R. Cao ◽  
Hong Liang Hou
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Superplastic Deformation ◽  
Initial Strain Rate ◽  
Deformation Mode ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Coarse Grained ◽  
Transmission Electron ◽  
Grain Growth Model

In this study, superplastic tensile tests were carried out for Ti-6Al-4V alloy using different initial grain sizes (2.6 μm, 6.5μm and 16.2 μm) at a temperature of 920°C with an initial strain rate of 1×10-3 s-1. To get an insight into the effect of grain size on the superplastic deformation mechanisms, the microstructures of deformed alloy were investigated by using an optical microscope and transmission electron microscope (TEM). The results indicate that there is dramatic difference in the superplastic deformation mode of fine and coarse grained Ti-6Al-4V alloy. Meanwhile, grain growth induced by superplastic deformation has also been clearly observed during deformation process, and the grain growth model including the static and strain induced part during superplastic deformation was utilized to analyze the data of Ti-6Al-4V alloy.

Change in Grain Size Distribution during Grain Growth

1992 ◽  
Vol 94-96 ◽  
pp. 325-330 ◽  
Author(s):  
Y. Takayama ◽  
T. Tozawa ◽  
H. Kato ◽  
Norio Furushiro ◽  
S. Hori
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Growth ◽  
Grain Size Distribution

A Study on The Phase Transformation and Exchange-Coupling of (Nd0 95La0 05)9 5FebalCo5Nb2B10.5 Nanocomposites

1999 ◽  
Vol 577 ◽  
Author(s):  
Q. Chen ◽  
B. M. Ma ◽  
B. Lu ◽  
M. Q. Huang ◽  
D. E. Laughlin
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Phase Transformation ◽  
Thermal Treatment ◽  
Grain Growth ◽  
Exchange Coupling ◽  
Phase Distribution ◽  
Maximum Energy ◽  
Treatment Temperature ◽  
Phase Identification

ABSTRACTThe phase transformation and the exchange coupling in (Ndo095Lao005)9.5FebaICOsNb 2BI05 have been investigated. Nanocomposites were obtained by treating amorphous precursors at temperatures ranging from 650TC to 9500C for 10 minutes. The magnetic properties were characterized via the vibrating sample magnetometer (VSM). X-ray diffraction (XRD), thermomagnetic analysis (TMA), and transmission electron microscopy (TEM) were used to perform phase identification, measure grain size, and analyze phase distribution. The strength of the exchange coupling between the magnetically hard and soft phases in the corresponding nanocomposite was analyzed via the AM-versus-H plot. It was found that the remanence (Br), coercivity (Hci), and maximum energy product (BHmax) obtained were affected by the magnetic phases present as well as the grain size of constituent phases and their distribution. The optimal magnetic performance, BHm, occurred between 700°C to 750°C, where the crystallization has completed without excessive grain growth. TMA and TEM indicated that the system was composed of three phases at this point, Nd2(Fe Co) 14B, ca-Fe, and Fe3B. The exchange coupling interaction among these phases was consistently described via the AM-versus-H plot up to 750°C. The Br, Hci, and BHmax degraded severely when the thermal treatment temperature increased from 750°C. This degradation may be attributed to the grain growth of the main phases, from 45 to 68nm, and the development of precipitates, which grew from 5nm at 750°C to 12nm at 850°C. Moreover, the amount of the precipitates was found to increase with the thermal treatment temperatures. The precipitates, presumably borides, may cause a decrease in the amount of the a-Fe and Fe 3B and result in a redistribution of the Co in the nanocomposites. The increase of the Co content in the Nd 2(Fe Co) 14B may explain the increase of its Curie temperature with the thermal treatment temperatures. In this paper, we examine the impacts of these factors on the magnetic properties of (Ndo 95Lao 05)9 5FebaICosNb2B10.5 nanocomposite.

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