scholarly journals Characterization and Prediction of Texture in Laser Annealed NiTi Shape Memory Thin Films

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Gen Satoh ◽  
Xu Huang ◽  
Ainissa G. Ramirez ◽  
Y. Lawrence Yao
Keyword(s):  
Thin Film ◽  
Monte Carlo ◽  
Shape Memory ◽  
Grain Growth ◽  
Electron Backscatter Diffraction ◽  
Three Dimensional ◽  
Laser Crystallization ◽  
Shape Memory Properties ◽  
Melting Regime ◽  
Grain Growth Model

Thin film shape memory alloys are a promising material for use in microscale devices for actuation and sensing due to their strong actuating force, substantial displacements, and large surface to volume ratios. NiTi, in particular, has been of great interest due to its biocompatibility and corrosion resistance. Effort has been directed toward adjusting the microstructure of as-deposited films in order to modify their shape memory properties for specific applications. The anisotropy of the shape memory and superelastic effects suggests that inducing preferred orientations could allow for optimization of shape memory properties. Limited work, however, has been performed on adjusting the crystallographic texture of these films. In this study, thin film NiTi samples are processed using excimer laser crystallization and the effect on the overall preferred orientation is analyzed through the use of electron backscatter diffraction and X-ray diffraction. A three-dimensional Monte Carlo grain growth model is developed to characterize textures formed though surface energy induced abnormal grain growth during solidification. Furthermore, a scaling factor between Monte Carlo steps and real time is determined to aid in the prediction of texture changes during laser crystallization in the partial melting regime.

scholarly journals Characterization and Prediction of Texture in Laser Annealed NiTi Shape Memory Thin Films

2010 ◽  
Author(s):  
Gen Satoh ◽  
Y. Lawrence Yao ◽  
Xu Huang ◽  
Ainissa Ramirez
Keyword(s):  
Thin Film ◽  
Monte Carlo ◽  
Shape Memory ◽  
Grain Growth ◽  
Electron Backscatter Diffraction ◽  
Laser Crystallization ◽  
3 Dimensional ◽  
Shape Memory Properties ◽  
Melting Regime ◽  
Grain Growth Model

Thin film shape memory alloys are a promising material for use in micro-scale devices for actuation and sensing due to their strong actuating force, substantial displacements, and large surface to volume ratios. NiTi, in particular, has been of great interest due to its biocompatibility and corrosion resistance. Effort has been directed toward adjusting the microstructure of as-deposited films in order to modify their shape memory properties for specific applications. The anisotropy of the shape memory and superelastic effects suggests that inducing preferred orientations could allow for optimization of shape memory properties. Limited work, however, has been performed on adjusting the crystallographic texture of these films. In this study, thin film NiTi samples are processed using excimer laser crystallization and the effect on the overall preferred orientation is analyzed through the use of electron backscatter diffraction and x-ray diffraction. A 3-dimensional Monte Carlo grain growth model is developed to characterize textures formed through surface energy induced abnormal grain growth during solidification. Furthermore, a scaling factor between Monte Carlo steps and real time is determined to aid in the prediction of texture changes during laser crystallization in the partial melting regime.

Three-dimensional monte-carlo simulation of grain growth in Pt-Co thin film

2002 ◽  
Vol 31 (10) ◽  
pp. 965-971 ◽  
Author(s):  
Sung Il Park ◽  
Sang Soo Han ◽  
Hyoung Gyu Kim ◽  
Joong Keun Park ◽  
Hyuck Mo Lee
Keyword(s):  
Thin Film ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Grain Growth ◽  
Three Dimensional

A Simple Statistical Theory for Grain Growth in Materials.

1990 ◽  
Vol 209 ◽  
Author(s):  
P. Mulheran ◽  
J.H. Harding
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Statistical Theory ◽  
Stochastic Model ◽  
Grain Growth ◽  
Three Dimensional ◽  
Monte Carlo Procedure ◽  
Short Time ◽  
2D And 3D ◽  
Good Agreement

A Monte Carlo procedure has been used to study the ordering of both two and three dimensional (2d and 3d) Potts Hamiltonians, further to the work of Anderson et al. For the 3d lattice, the short time growth rate is found to be much slower than previously reported, though the simulated microstructure is in agreement with the earlier studies. We propose a new stochastic model that gives good agreement with the simulations.

Monte-Carlo Simulation of Goss Abnormal Grain Growth in Fe-3%Si Steel by Sub-Boundary Enhanced Solid-State Wetting

2012 ◽  
Vol 715-716 ◽  
pp. 146-151
Author(s):  
K.J. Ko ◽  
A.D. Rollett ◽  
N.M. Hwang
Keyword(s):  
Monte Carlo ◽  
Solid State ◽  
Grain Boundary ◽  
Grain Growth ◽  
Boundary Energy ◽  
Three Dimensional ◽  
Abnormal Grain Growth ◽  
Grain Boundary Energy ◽  
Simulation Based ◽  
Mc Simulation

The selective abnormal grain growth (AGG) of Goss grains in Fe-3%Si steel was investigated using a parallel Monte-Carlo (MC) simulation based on the new concept of sub-boundary enhanced solid-state wetting. Goss grains with low angle sub-boundaries will induce solid-state wetting against matrix grains with a moderate variation in grain boundary energy. Three-dimensional MC simulations of microstructure evolution with textures and grain boundary distributions matched to experimental data is using in this study.

Effect of the Intercalation of the Carbon Layer on the Kinetics of Grain Growth of FePt Magnetic Thin Film during Ordering Reaction - A Monte Carlo Simulation Study

2007 ◽  
Vol 558-559 ◽  
pp. 1237-1242
Author(s):  
M.C. Kim ◽  
D.A. Kim ◽  
Joong Kuen Park
Keyword(s):  
Thin Film ◽  
Monte Carlo Simulation ◽  
Grain Size ◽  
Monte Carlo ◽  
Grain Growth ◽  
Carbon Layer ◽  
Carbon Addition ◽  
Monte Carlo Simulation Study ◽  
Ordering Kinetics ◽  
Kinetics Of

The effect of carbon addition on the grain growth and ordering kinetics of FePt film has been experimentally studied by sputter-depositing a monolithic FePt-20at.%C film of 24 nm. Carbon addition of 20at.% to FePt thin film in a form of FePt (20 nm)/Cn (4 nm) (n = 1, 4) significantly reduced both the grain growth and ordering kinetics. Reducing the thickness of carbon layer, i.e. from n = 1 to n = 4, led to a much finer grain size distribution as well as to a finer grain size. The Monte Carlo simulation study indicated that the decrease of grain growth and ordering kinetics is primarily due to a continuous decrease of the mobility of order – disorder inter-phase with the progress of ordering reaction. This can eventually lead to a stable 2-phase grain structure inter-locked by low mobility inter-phases and is responsible for the formation of a fine grain size distribution in the FePt/Cn film with n = 4.

scholarly journals Mechanical, Thermal, and Shape Memory Properties of Three-Dimensional Printing Biomass Composites

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1234 ◽  
Author(s):  
Hongjie Bi ◽  
Min Xu ◽  
Gaoyuan Ye ◽  
Rui Guo ◽  
Liping Cai ◽  
...  
Keyword(s):  
Shape Memory ◽  
Wood Flour ◽  
Memory Performance ◽  
Thermoplastic Polyurethane ◽  
Tensile Elongation ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Shape Memory Properties ◽  
Shape Memory Composites ◽  
Recovery Angle

In this study, a series of heat-induced shape memory composites was prepared by the hot-melt extrusion and three-dimensional (3D) printing of thermoplastic polyurethane (TPU) using wood flour (WF) with different contents of EPDM-g-MAH. The mechanical properties, microtopography, thermal property analysis, and heat-induced shape memory properties of the composites were examined. The results showed that, when the EPDM-g-MAH content was 4%, the tensile elongation and tensile strength of the composites reached the maximum value. The scanning electron microscopy and dynamic mechanical analysis results revealed a good interface bonding between TPU and WF when the EPDM-g-MAH content was 4%. The thermogravimetric analysis indicated that the thermal stability of TPU/WF composites was enhanced by the addition of 4% EPDM-g-MAH. Heat-induced shape memory test results showed that the shape memory performance of composites with 4% EPDM-g-MAH was better than that of unmodified-composites. The composites’ shape recovery performance at a temperature of 60 °C was higher than that of the composites at ambient temperature. It was also found that, when the filling angle of the specimen was 45°, the recovery angle of the composites was larger.

Characteristics of Ti-Ni-Zr Thin Film Metallic Glasses / Thin Film Shape Memory Alloys for Micro Actuators with Three-Dimensional Structures

2015 ◽  
Vol 9 (6) ◽  
pp. 662-667 ◽  
Author(s):  
Junpei Sakurai ◽  
◽  
Seiichi Hata
Keyword(s):  
Thin Film ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Metallic Glasses ◽  
Microelectromechanical Systems ◽  
Three Dimensional ◽  
Eutectic Point ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region

In this paper, we investigate the characteristics of Ti-Ni-Zr thin film metallic glasses (TFMGs)/ shape memory alloys (SMAs) for microelectromechanical systems (MEMS) applications with three-dimensional structures. The amorphous Ti-Ni-Zr thin films having a Ni content of more than 50 at.% and Zr content of more than 11 at.% undergo glass transitions and are TFMGs. The Ti39Ni50Zr11TFMG has the lowest glass transition temperatureTgof 703 K and a wide supercooled liquid region ΔTof 57 K. Moreover, it has high thermal stability atTg. However, the apparent viscosity of the Ti39Ni50Zr11is higher than those of other Ti-Ni-Zr TFMGs. Moreover, the Ti-Ni-Zr TFMG exhibits higher viscosity than conventional TFMGs because the alloy composition of Ti-Ni-Zr TFMGs/SMAs is far from the eutectic point.

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