scholarly journals Improvement on Thermal Stability of Nano-Domains in Lithium Niobate Thin Films

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 74 ◽  
Author(s):  
Yuejian Jiao ◽  
Zhen Shao ◽  
Sanbing Li ◽  
Xiaojie Wang ◽  
Fang Bo ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Lithium Niobate ◽  
Treatment Process ◽  
Annealing Treatment ◽  
Heat Treatment Process ◽  
Atomic Force ◽  
Thermal Annealing Treatment ◽  
Charge Field ◽  
Thermal Stability Of

We present a simple and effective way to improve the thermal stability of nano-domains written with an atomic force microscope (AFM)-tip voltage in a lithium niobate film on insulator (LNOI). We show that nano-domains in LNOI (whether in the form of stripe domains or dot domains) degraded, or even disappeared, after a post-poling thermal annealing treatment at a temperature on the order of ∼100 ∘ C. We experimentally confirmed that the thermal stability of nano-domains in LNOI is greatly improved if a pre-heat treatment is carried out for LNOI before the nano-domains are written. This thermal stability improvement of nano-domains is mainly attributed to the generation of a compensating space charge field parallel to the spontaneous polarization of written nano-domains during the pre-heat treatment process.

Effects of Different Heat Treatments on Transformation of Residual Austenite in Bearing Steel

2014 ◽  
Vol 670-671 ◽  
pp. 56-60
Author(s):  
H.S. Liu ◽  
M.H. Wang ◽  
X.Y. Ge ◽  
H.S. Luo
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Treatment Process ◽  
Cryogenic Treatment ◽  
Residual Austenite ◽  
Bearing Steel ◽  
Heat Treatment Process ◽  
Austenite Content ◽  
Quenching Process ◽  
Thermal Stability Of

The effect of heat treatment on transformation of residual austenite in bearing steel is studied, by adding the cryogenic treatment into the normal heat treatment process. The results indicate that the residual austenite content is decreased and the hardness is improved obviously, when putting the cryogenic treatment at -70°C or lower directly behind the quenching process. While when the tempering is added between quench and cryogenic treatment, the temperature of cryogenic treatment must be much lower than -70°C to offset the thermal stability of residual austenite, which is given by tempering.

Study of Cu Addition on Precipitation Behaviors and Mechanical Properties in AA6082 Al-Mg-Si Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 825-828 ◽  
Author(s):  
Man Jin ◽  
Jing Li ◽  
Guang Jie Shao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Thermal Stability ◽  
Treatment Process ◽  
Mechanical Tests ◽  
Age Hardening ◽  
Heat Treatment Process ◽  
Softening Process

The precipitation behaviors and microstructures of nano-precipitates in AA6082 Al-Mg-Si alloy with and without Cu additions during heat treatment process were studied using hardness measurements, TEM, mechanical tests and 3DAP. Meanwhile, the softening process of 6082 alloys with Cu and without Cu, isothermally conditioned at 250°C, has also been investigated. It was found that the rate of age hardening, mechanical properties and thermal stability are higher for the Cu-containing alloy. The TEM and 3DAP observations showed that Q’ precipitates were existed after aged at 170°C for 8h in the alloy with Cu addition. Comparing the hardness, mechanical properties and thermal stability curves, it was concluded that the Q’ precipitates play a major role in improving the age hardening kinetics and properties of 6082 alloy with Cu addition.

Optimization of Heat Treatment Process of ZE41A Magnesium Alloy Using Grey- Based Taguchi Method

2008 ◽  
Vol 3 (2) ◽  
pp. 63-69
Author(s):  
M. Sivapragash ◽  
◽  
V. Sateeshkumar ◽  
P.R. Lakshminarayanan ◽  
R. Karthikeyan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Taguchi Method ◽  
Treatment Process ◽  
Heat Treatment Process

EFFECT ON HARDNESS and MICRO STRUCTURAL BEHAVIOUR OF TOOL STEEL AFTER HEAT TREATMENT PROCESS

2017 ◽  
Vol 4 (24) ◽  
Author(s):  
Karanbir Singh ◽  
Aditya Chhabra ◽  
Vaibhav Kapoor ◽  
Vaibhav Kapoor
Keyword(s):  
Heat Treatment ◽  
Empirical Study ◽  
Tool Steel ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Structural Behaviour ◽  
Treatment Processes ◽  
En 31

This study is conducted to analyze the effect on the Hardness and Micro Structural Behaviour of three Sample Grades of Tool Steel i.e. EN-31, EN-8, and D3 after Heat Treatment Processes Such As Annealing, Normalizing, and Hardening and Tempering. The purpose of Selecting Tool Steel is Because Tool Steel is Mostly Used in the Manufacturing Industry.This study is based upon the empirical study which means it is derived from experiment and observation rather than theory.

Thermal stability of phase-separated nanograin structure during heat treatment

2021 ◽  
Vol 875 ◽  
pp. 160055
Author(s):  
Hua Guo ◽  
Fawei Tang ◽  
Yong Liu ◽  
Zhi Zhao ◽  
Hao Lu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Thermal Stability Of

Influence of trisilanol isooctyl POSS content on the structure, morphology and rheological properties of thermoplastic polyurethane (TPU)

2020 ◽  
Vol 40 (9) ◽  
pp. 727-735
Author(s):  
Rudinei Fiorio ◽  
Chaitanya Danda ◽  
João Maia
Keyword(s):  
Thermal Stability ◽  
Rheological Properties ◽  
Thermoplastic Polyurethane ◽  
Reactive Extrusion ◽  
Strain Rates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Extensional Strain ◽  
Oligomeric Silsesquioxane ◽  
Thermal Stability Of

AbstractIn this study, thermoplastic polyurethanes (TPUs) containing trisilanol isooctyl polyhedral oligomeric silsesquioxane (POSS), a reactive nanofiller, were synthesized and characterized rheologically and morphologically, and the effects of POSS content on the melt thermal stability of the TPUs are investigated. Samples containing 0, 0.23, 0.57, 1.14, and 2.23% (w/w) POSS were synthesized by reactive extrusion and characterized by Fourier transform infrared spectroscopy (FTIR), oscillatory and extensional rheometry, atomic force microscopy (AFM), and small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). The rheological properties of molten TPU are time-dependent and the melt thermal stability of the TPU is maximal at 1.14% of POSS. The addition of 0.23 and 0.57% POSS promotes strain-hardening at low extensional strain rates (0.01 and 0.10 s−1), not affecting the extensional characteristics at higher strain rates. The addition of increasing amounts of POSS leads to the formation of POSS-rich clusters well dispersed in the TPU matrix. SAXS and WAXS results show that the POSS domains are amorphous and that POSS does not modify the crystalline structure of TPU. Therefore, this work indicates that synthesizing TPU in the presence of trisilanol isooctyl POSS can increase the melt thermal stability of the polymer, facilitating its processing.

Failure Analysis on a Counterweight Assembly of an Aeroengine

2011 ◽  
Vol 339 ◽  
pp. 342-348
Author(s):  
Hai Jun Tang ◽  
Hong Yu Yao
Keyword(s):  
Heat Treatment ◽  
Stress Concentration ◽  
Failure Analysis ◽  
Failure Mechanism ◽  
Treatment Process ◽  
Hardness Test ◽  
Heat Treatment Process ◽  
Material Loss ◽  
Structure Strength ◽  
Crucial Part

The paper presents a failure analysis on a counterweight assembly installed on crank shaft which resulted in an in-flight shutdown of a piston aeroengine. The counterweight assembly failure includes counterweight block material loss and fractured washer which is the most crucial part for in-flight shutdown in this type of aeroengine. Macro observation, fractography analysis, metallography analysis and hardness test were conducted on the failed counterweight assembly. The result shows that failure mechanism of counterweight block and washer is fatigue. The washer failure is likely due to inappropriate heat treatment process and continuous impact in flight by slightly tilted roller. Counterweight material loss is attributed to stress concentration, low structure strength and impact came from the tilted roller. Finally some safety suggestion on design and maintenance is given.

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