scholarly journals Residual Stress Determination from a Laser-Based Curvature Measurement

2000 ◽  
Author(s):  
W.D. Swank ◽  
R.A. Gavalya ◽  
J.K. Wright ◽  
R.N. Wright
Keyword(s):  
Residual Stress ◽  
Thermal Expansion ◽  
Bond Coat ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Substrate Material ◽  
304 Stainless Steel ◽  
Cte Mismatch ◽  
Mismatch Stress ◽  
Sprayed Coating

Abstract Thermally sprayed coating characteristics and mechanical properties are in part a result of the residual stress developed during the fabrication process. The total stress state in a coating/substrate is comprised of the quench stress and the coefficient of thermal expansion (CTE) mismatch stress. The quench stress is developed when molten particles impact the substrate and rapidly cool and solidify. The CTE mismatch stress results from a large difference in the thermal expansion coefficients of the coating and substrate material. It comes into effect when the substrate/coating combination cools from the equilibrated deposit temperature to room temperature. This paper describes a laser-based technique for measuring the curvature of a coated substrate and the analysis required to determine residual stress from curvature measurements. Quench stresses were determined by heating the specimen back to the deposit temperature thus removing the CTE mismatch stress. By subtracting the quench stress from the total residual stress at room temperature, the CTE mismatch stress was estimated. Residual stress measurements for thick (>1mm) spinel coatings with a Ni-Al bond coat on 304 stainless steel substrates were made. It was determined that a significant portion of the residual stress results from the quenching stress of the bond coat and that the spinel coating produces a larger CTE mismatch stress than quench stress.

Effect of Thermal Residual Stresses on Polymer/Metal Interfacial Adhesion

1999 ◽  
Author(s):  
Qizhou Yao ◽  
Jianmin Qu
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Coefficient Of Thermal Expansion ◽  
Interfacial Crack ◽  
Thermal Residual Stress ◽  
Element Analysis ◽  
Thermal Residual Stresses ◽  
Interfacial Cracks ◽  
Cte Mismatch ◽  
Elastic Mismatch

Abstract In this study, the apparent fracture toughness of the interfaces of several epoxy-based polymeric adhesives and metal (aluminum) substrate is experimentally measured. Double layer specimens with initial interfacial cracks are made for four-point bending tests. Thermal residual stresses exist on the interface due to the coefficient of thermal expansion (CTE) mismatch between the underfill and aluminum. Silica fillers are used to modify the CTE of the epoxy-based adhesives so that various levels of interface thermal residual stresses are achieved. Finite element analysis is also performed to quantify the effects of CTE mismatch as well as the elastic mismatch across the interface. It is found that the apparent interfacial toughness is significantly affected by the thermal residual stress, while the effect of elastic mismatch is negligible. In general thermal residual stress undermines the resistance to an interfacial crack. In some cases the residual stress is sufficient to result in adhesive and/or cohesive failure.

Tangguh LNG Project Statistical Young’s Modulus and Thermal Expansion Coefficient Testing of Clad Pipe Specimens

2011 ◽  
Author(s):  
Terry Griffiths ◽  
Isabel Hadley ◽  
Richard Johnson ◽  
Fabio Micari
Keyword(s):  
Thermal Expansion ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Structural Reliability ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Linear Thermal Expansion ◽  
Upheaval Buckling ◽  
Analysis Of Results ◽  
Mean And Variance

Material testing was undertaken on samples taken from clad pipe manufactured by JSW for the Tangguh LNG project. The test programme involved testing Young’s Modulus (E) and Coefficient of Linear Thermal Expansion (α) from room temperature to above 110° on each layer. This paper summarises testing and analysis of results which enabled mean and variance on each material property to be found. Checks were also undertaken for any correlations in properties between clad and parent layers, and between Young’s Modulus and Coefficient of Thermal Expansion. Analysis results are compared to existing industry norms and their implications for the Tangguh project UHB (Upheaval Buckling) SRA (Structural Reliability Analysis) are summarised.

scholarly journals Effect of Residual Stress on Thermal Deformation Behavior

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4141
Author(s):  
Sasaki ◽  
Yoshida ◽  
Ogawa ◽  
Shitaka ◽  
McGibboney
Keyword(s):  
Residual Stress ◽  
Thermal Expansion ◽  
Deformation Behavior ◽  
Thermal Deformation ◽  
Coefficient Of Thermal Expansion ◽  
Speckle Pattern ◽  
Steel Specimen ◽  
Fringe Analysis ◽  
Dissimilar Joints ◽  
Optical Visualization

This paper discusses a non-destructive measurement technique of residual stress through optical visualization. The least amount of deformation possible is applied to steel plates by heating the specimens +10 °C from room temperature for initial calibration, and the thermal expansion behavior is visualized with an electronic speckle pattern interferometer sensitive to two dimensional in-plane displacement. Displacement distribution with the thermal deformation and coefficient of thermal expansion are obtained through interferometric fringe analysis. The results suggest the change in the thermal deformation behavior is affected by the external stress initially applied to the steel specimen. Additionally, dissimilar joints of steel and cemented carbide plates are prepared by butt-brazing. The residual stress is estimated based on the stress dependence of thermal expansion coefficient.

Control of zero-crossing temperature of coefficient of thermal expansion and reduction of mechanical residual stress for TiO2–SiO2glass optical cavity

2015 ◽  
Vol 54 (9) ◽  
pp. 096702 ◽  
Author(s):  
Mototaka Arakawa ◽  
Jun-ichi Kushibiki ◽  
Yuji Ohashi ◽  
Yuko Maruyama ◽  
Naofumi Yamada ◽  
...  
Keyword(s):  
Residual Stress ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Optical Cavity ◽  
Zero Crossing

The Influence of Microstructure, Heat-Treatment and Type of Crystal Lattice of Iron Aluminides on Coefficient of Thermal Expansion

2016 ◽  
Vol 368 ◽  
pp. 41-44 ◽  
Author(s):  
Martin Švec
Keyword(s):  
Phase Transition ◽  
Heat Treatment ◽  
Thermal Expansion ◽  
High Temperature ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Iron Aluminides ◽  
Sharp Drop ◽  
Structural Application ◽  
Phase Transition Temperatures

The iron aluminides seem to be very perspective materials for high temperature structural application. They have many advantages, but unfortunately also some negative properties – e.g. sharp drop in strength above 600°C or limited ductility at room temperature. These disadvantages can be reduced by alloying of binary alloy by other elements.Present work deals with a study of coefficient of thermal expansion (CTE). It was investigated the influence of microstructure and heat-treatment on the values of CTE. Secondary, it was studied the possibilities, how to determine phase transition temperatures from CTE curves. Influence of type of iron aluminides lattice on CTE values was also examined as well as the influence of addition of alloying elements into binary iron aluminides.

scholarly journals Thermal expansion and atomic displacement parameters of cubic KMgF3perovskite determined by high-resolution neutron powder diffraction

2002 ◽  
Vol 35 (3) ◽  
pp. 291-295 ◽  
Author(s):  
I. G. Wood ◽  
K. S. Knight ◽  
G. D. Price ◽  
J. A. Stuart
Keyword(s):  
Thermal Expansion ◽  
High Resolution ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Atomic Displacement ◽  
Debye Model ◽  
Neutron Powder Diffraction ◽  
First Derivative ◽  
Atomic Displacement Parameters

The structure of KMgF3has been determined by high-resolution neutron powder diffraction at 4.2 K, room temperature and at 10 K intervals from 373 K to 1223 K. The material remains cubic at all temperatures. The average volumetric coefficient of thermal expansion in the range 373–1223 K was found to be 7.11 (3) × 10−5 K−1. For temperatures between 4.2 and 1223 K, a second-order Grüneisen approximation to the zero-pressure equation of state, with the internal energy calculatedviaa Debye model, was found to fit well, with the following parameters: θD= 536 (9) K,Vo= 62.876 (6) Å3, K_{o}^{\,\prime} = 6.5 (1) and (VoKo/γ′) = 3.40 (2) × 10−18 J, where θDis the Debye temperature,Vois the volume atT= 0, K_{o}^{\,\prime} is the first derivative with respect to pressure of the incompressibility (Ko) and γ′ is a Grüneisen parameter. The atomic displacement parameters were found to increase smoothly withTand could be fitted using Debye models with θDin the range 305–581 K. At 1223 K, the displacement of the F ions was found to be much less anisotropic than that in NaMgF3at this temperature.

The Linear Coefficient of Thermal Expansion of Silicon at Room Temperature

1991 ◽  
Vol 6 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Liu Fengchao ◽  
Zheng Bin
Keyword(s):  
Thermal Expansion ◽  
Single Crystal ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Silicon Single Crystal ◽  
Linear Coefficient ◽  
X Ray ◽  
Crystal State ◽  
Powder Diffractometer ◽  
Powder Samples

AbstractThe linear coefficient of thermal expansion for three silicon single-crystal samples, taken from the head, middle, and tail of the same boule, and their powder samples have been measured at room temperature by using an X-ray powder diffractometer. All samples yield the same expansion value α=2.45 (± 0.04) × 10−6 °C at 25 °C. The results of this experiment show that the linear coefficient of thermal expansion of silicon at room temperature is not dependent on its single-crystal state or its powder state.

Li2O-Al2O3-SiO2 Glass-Ceramics Used As Anodic Bonding Materials

2008 ◽  
Vol 368-372 ◽  
pp. 1436-1438 ◽  
Author(s):  
Hong Li ◽  
Yun Du ◽  
Jin Shu Cheng ◽  
Tian He Wang
Keyword(s):  
Heat Treatment ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Glass Ceramics ◽  
Treatment Method ◽  
Substrate Material ◽  
Anodic Bonding ◽  
Treatment Schedule ◽  
Crystal Phases ◽  
Step Heat Treatment

The glass-ceramics, whose coefficient of thermal expansion approximately matched to that of silicon, were studied to replace conventional heat-resistant glass as substrate material for anodic bonding. The basic glasses of the Li2O-Al2O3-SiO2 system with TiO2 and ZrO2 as nucleation agents were prepared by melting technology, and the temperatures of nucleation and crystallization were determined. The glass-ceramics were obtained by two-step heat-treatment method. The oriented crystallization of glasses in gradient temperature field was studied. The crystal phases and microstructures of glass- ceramics were analyzed. Effect of heat-treatment schedule on the coefficient of thermal expansion was discussed. The results showed that the most of the main crystal phases of the samples were β-spodumene. The coefficient of thermal expansion of sample was about 32.5×10-7/°C, which was approach to that of silicon.

X-Ray Stress Measurement of Alloy Steels X-Ray Study of Elastic Deformation for Alloy Steels with Composite Microstructures

1993 ◽  
Vol 37 ◽  
pp. 317-325
Author(s):  
Masaaki Tsuda ◽  
Tokimasa Goto ◽  
Toshihiko Sasaki ◽  
Yukio Hirose
Keyword(s):  
Residual Stress ◽  
Thermal Expansion ◽  
Elastic Deformation ◽  
Stress Measurement ◽  
Coefficient Of Thermal Expansion ◽  
Ray Method ◽  
Toughening Mechanisms ◽  
X Ray ◽  
Alloy Steels

Residual stress is inevitably introduced into composites because of the mismatch of the coefficient of thermal expansion, and it is different for each phase. The x-ray method can detect separately the stress in each phase, so will yield useful information for analyzing the toughening mechanisms of composites.

Functionally Gradient 3YSZ-IN713LC Composites

2008 ◽  
Vol 47-50 ◽  
pp. 5-8
Author(s):  
D.H. Kuo ◽  
R.K. Shiue ◽  
W.Y. Tseng ◽  
C.H. Shih ◽  
T.Y. Yeh ◽  
...  
Keyword(s):  
Residual Stress ◽  
Thermal Expansion ◽  
Compressive Stress ◽  
Coefficient Of Thermal Expansion ◽  
Functionally Gradient Materials ◽  
Monotonic Change ◽  
Gradient Materials ◽  
Linear Mode ◽  
Functionally Gradient ◽  
Fracture Behaviors

Functionally gradient materials (FGMs) composed of 3YSZ and IN713LC were developed in three different configurations. A linear-mode FGM had its compositions with a monotonic change in coefficient of thermal expansion (CTE). Negative- and positive-deviated FGMs had their compositions with lower and higher CTEs, respectively, on the ceramic sides. Fracture behaviors of these three types of FGMs were evaluated with aids of residual stress analyses. FGMs with a positive CTE deviation demonstrated the best performance in the experiment. The brittle ceramic side was under high compressive stress, and high tensile stresses were primarily initiated in the metal-rich gradient layers.

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