scholarly journals Effect of Heat Treatment of Si3N4 on Grain Growth Behavior and Grain Boundary Structure

1997 ◽  
Vol 105 (1219) ◽  
pp. 218-222
Author(s):  
Naoto HIROSAKI ◽  
Hideaki MATSUBARA
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Grain Growth ◽  
Growth Behavior ◽  
Boundary Structure ◽  
Grain Boundary Structure ◽  
Grain Growth Behavior

Boundary Structure-Dependent Grain Growth Behavior in Polycrystals: Model and Principle

2013 ◽  
Vol 753 ◽  
pp. 377-382 ◽  
Author(s):  
Suk Joong L. Kang
Keyword(s):  
Grain Growth ◽  
Microstructural Evolution ◽  
Driving Force ◽  
Coupling Effect ◽  
Normal Growth ◽  
Growth Behavior ◽  
Boundary Structure ◽  
Mixed Control ◽  
Grain Boundary Structure ◽  
Grain Growth Behavior

This paper reviews our recent investigations on grain growth in ceramics. Grain growth behavior has been found to be governed by the grain boundary structure: normal growth with a stationary relative grain size distribution for rough boundaries and non-normal (nonstationary) growth for faceted boundaries. Based on the concept of nonlinear migration of faceted boundaries, the mixed control model of grain growth is introduced and the principle of microstructural evolution is deduced. This principle states that various types of grain growth behavior are predicted as a result of the coupling effect between the maximum driving force for growth and the critical driving force for appreciable migration of the boundary. A wealth of experimental results supports the theoretical predictions of grain growth behavior, showing the generality of the suggested principle of microstructural evolution. Application of this principle is also demonstrated for the fabrication of single crystals as well as polycrystals with desired microstructures.

Grain boundary structure in TiO2-excess barium titanate

1998 ◽  
Vol 13 (12) ◽  
pp. 3449-3452 ◽  
Author(s):  
Takahisa Yamamoto ◽  
Yuichi Ikuhara ◽  
Katsuro Hayashi ◽  
Taketo Sakuma
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
High Resolution Electron Microscopy ◽  
Growth Behavior ◽  
Boundary Structure ◽  
Grain Boundary Structure ◽  
Resolution Electron ◽  
Grain Growth Behavior ◽  
Electron Energy Loss

Grain boundary structure was examined in 0.1 mol% TiO2-excess BaTiO3 by high-resolution electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). Their grain boundaries were mostly faceted with {210} type habit. The faceted boundaries were characterized to be associated with an extra Ti–O2 bond with the rutile-like structure. The grain growth behavior in a small TiO2-excess BaTiO3 is discussed from the viewpoint of grain boundary structure.

Grain Growth Behavior and Mechanical Properties of the Friction Stir Welded Zone of 7055 Al Alloy Followed by Post Weld Heat Treatment

2007 ◽  
Vol 539-543 ◽  
pp. 4087-4092 ◽  
Author(s):  
Won Bae Lee ◽  
Chang Yong Lee ◽  
Yun Mo Yeon ◽  
Jong Bong Lee ◽  
Shur Chang Chae ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Growth ◽  
Weld Zone ◽  
Growth Behavior ◽  
Post Weld Heat Treatment ◽  
Friction Stir ◽  
Input Condition ◽  
Lower Heat ◽  
Grain Growth Behavior

The grain growth behavior and mechanical properties in the friction stir weld zone after post weld heat treatment (PWHT) have been investigated. As PWHT temperature increased, a normal grain growth of as-welded equaxied grains ceased and abnormally grown grains with elongated shape coarsened. Huge elongated grains changed into smaller equaxied grains at 500°C. In case of lower heat input condition, abnormal grain growth initiated faster due to smaller initial grain size. The weld zone with bigger initial grains had advantages to maintain the thermal stability at high temperature. The hardness near the weld zone was almost recovered to the 95% of the unaffected base metal at 500 °C and the weld zone under lower heat input condition resulted in the homogeneous recovery through the whole weld zone.

scholarly journals Grain and Grain Boundary Structure Evolution Without Texture Changes During Normal Grain Growth in 2-D Al Strips

1999 ◽  
Vol 32 (1-4) ◽  
pp. 187-195 ◽  
Author(s):  
V. Sursaeva ◽  
U. Czubayko ◽  
A. Touflin
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Columnar Structure ◽  
Boundary Structure ◽  
Structure Evolution ◽  
Grain Boundary Character Distribution ◽  
Grain Boundary Character ◽  
Grain Boundary Structure ◽  
Texture Change ◽  
Character Distribution

Changes of the grain boundary character distribution and texture during normal grain growth have been investigated using the SAC-SEM based method and a 4 circle X-ray texture goniometer on A1 strips with columnar structure. The microstructure of the strips consists of regions with oriented (clusters) and randomly oriented grains. All changes of microstructure are outside the clusters during normal grain growth and consequently no texture change was observed.

scholarly journals Machine Learning for Competitive Grain Growth Behavior in Additive Manufacturing Ti6Al4V

2020 ◽  
Vol 321 ◽  
pp. 03004
Author(s):  
Jinghao Li ◽  
Manuel Sage ◽  
Xianglin Zhou ◽  
Mathieu Brochu ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Additive Manufacturing ◽  
Grain Boundary ◽  
Grain Growth ◽  
Manufacturing Industry ◽  
Energy Deposition ◽  
Growth Behavior ◽  
Direct Energy Deposition ◽  
Direct Energy ◽  
Grain Growth Behavior ◽  
Metal Additive

Metal additive manufacturing (MAM) technology is now changing the pattern of the high-end manufacturing industry, among which MAM fabricated Ti6Al4V has been far the most extensively investigated material and attracts a lot of research interests. This work established a deep neural network (DNN) to investigate the grain boundary in competitive grain growth for a bi-crystal system, the column β grains of Ti6Al4V as an example. Because of the limited number of experimental samples, the DNN is trained based on the data coming from the Geometrical Limited criterion. A series of direct energy deposition experiment using Ti6Al4V is carried out under the Taguchi experimental design. The grain boundary angles between the column grains are measured in the experiment and used to evaluate the accuracy of DNN.

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