scholarly journals Measurement of the Anisotropic Dynamic Elastic Constants of Additive Manufactured and Wrought Ti6Al4V Alloys

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 638
Author(s):  
Ofer Tevet ◽  
David Svetlizky ◽  
David Harel ◽  
Zahava Barkay ◽  
Dolev Geva ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Elastic Constants ◽  
Electron Backscatter Diffraction ◽  
Mechanical Design ◽  
Rolling Direction ◽  
Micro Computed Tomography ◽  
Phase Layer ◽  
Anisotropic Elastic ◽  
Hot Rolled ◽  
Pulse Echo

Additively manufactured (AM) materials and hot rolled materials are typically orthotropic, and exhibit anisotropic elastic properties. This paper elucidates the anisotropic elastic properties (Young’s modulus, shear modulus, and Poisson’s ratio) of Ti6Al4V alloy in four different conditions: three AM (by selective laser melting, SLM, electron beam melting, EBM, and directed energy deposition, DED, processes) and one wrought alloy (for comparison). A specially designed polygon sample allowed measurement of 12 sound wave velocities (SWVs), employing the dynamic pulse-echo ultrasonic technique. In conjunction with the measured density values, these SWVs enabled deriving of the tensor of elastic constants (Cij) and the three-dimensional (3D) Young’s moduli maps. Electron backscatter diffraction (EBSD) and micro-computed tomography (μCT) were employed to characterize the grain size and orientation as well as porosity and other defects which could explain the difference in the measured elastic constants of the four materials. All three types of AM materials showed only minor anisotropy. The wrought (hot rolled) alloy exhibited the highest density, virtually pore-free μCT images, and the highest ultrasonic anisotropy and polarity behavior. EBSD analysis revealed that a thin β-phase layer that formed along the elongated grain boundaries caused the ultrasonic polarity behavior. The finding that the elastic properties depend on the manufacturing process and on the angle relative to either the rolling direction or the AM build direction should be taken into account in the design of products. The data reported herein is valuable for materials selection and finite element analyses in mechanical design. The pulse-echo measurement procedure employed in this study may be further adapted and used for quality control of AM materials and parts.

Elastic Properties of Human Osteon and Osteonal Lamella Computed by a Bidirectional Micromechanical Model and Validated by Nanoindentation

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Radim Korsa ◽  
Jaroslav Lukes ◽  
Josef Sepitka ◽  
Tomas Mares
Keyword(s):  
Cortical Bone ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Micromechanical Model ◽  
Degenerative Diseases ◽  
Coordinate Systems ◽  
Inverse Homogenization ◽  
Curvilinear Coordinate ◽  
Anisotropic Elastic ◽  
Good Agreement

Knowledge of the anisotropic elastic properties of osteon and osteonal lamellae provides a better understanding of various pathophysiological conditions, such as aging, osteoporosis, osteoarthritis, and other degenerative diseases. For this reason, it is important to investigate and understand the elasticity of cortical bone. We created a bidirectional micromechanical model based on inverse homogenization for predicting the elastic properties of osteon and osteonal lamellae of cortical bone. The shape, the dimensions, and the curvature of osteon and osteonal lamellae are described by appropriately chosen curvilinear coordinate systems, so that the model operates close to the real morphology of these bone components. The model was used to calculate nine orthotropic elastic constants of osteonal lamellae. The input values have the elastic properties of a single osteon. We also expressed the dependence of the elastic properties of the lamellae on the angle of orientation. To validate the model, we performed nanoindentation tests on several osteonal lamellae. We compared the experimental results with the calculated results, and there was good agreement between them. The inverted model was used to calculate the elastic properties of a single osteon, where the input values are the elastic constants of osteonal lamellae. These calculations reveal that the model can be used in both directions of homogenization, i.e., direct homogenization and also inverse homogenization. The model described here can provide either the unknown elastic properties of a single lamella from the known elastic properties at the level of a single osteon, or the unknown elastic properties of a single osteon from the known elastic properties at the level of a single lamella.

Implementation of Twin Reorientation and Softening Schemes in a Polycrystal Plasticity Model for Mg Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 1063-1068
Author(s):  
Shi Hoon Choi ◽  
Y.S. Song ◽  
Jong Kweon Kim ◽  
B.J. Jung ◽  
Yong Bum Park
Keyword(s):  
Uniaxial Compression ◽  
Work Hardening ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
Rolling Direction ◽  
Peak Stress ◽  
Deformation Twinning ◽  
Compression Tests ◽  
Polycrystal Plasticity ◽  
Hot Rolled

Uniaxial compression tests on hot-rolled AZ31 Mg alloy were carried out at a temperature of 300°C. In order to investigate work hardening and texture evolution during plastic deformation, cylindrical specimens were compressed to the rolling direction. Experimental investigation reveals that flow curves are strongly dependent on microstructure evolution such as deformation twinning and softening phenomenon. The occurrence of deformation twinning and softening phenomenon was revealed by the observation of microtexture using electron backscatter diffraction (EBSD). A visco-plastic self-consistent (VPSC) polycrystal model was used to simulate the work hardening, softening and texture evolution during the uniaxial compression. In order to calculate orientation of deformation twins, predominant twin reorientation (PTR) scheme was implemented into the polycrystal model. A softening scheme was also implemented in the polycrystal model to predict softening phenomenon and texture evolution after a peak stress.

Effect of Bi2O3 on Elastic Properties of Silica Bismuthate Glasses by Pulse-Echo Method

2012 ◽  
Vol 2 (5) ◽  
pp. 546-548
Author(s):  
P. Vasantharani P. Vasantharani ◽  
◽  
I.Sankeeda I.Sankeeda
Keyword(s):  
Elastic Properties ◽  
Pulse Echo ◽  
Pulse Echo Method

INVERSION OF ANISOTROPIC ELASTIC CONSTANTS AND MUD SPEED USING BOREHOLE SONIC MODES

2020 ◽  
Author(s):  
Ting Lei ◽  
◽  
Romain Prioul ◽  
Adam Donald ◽  
Edgar Ignacio Velez Arteaga ◽  
...  
Keyword(s):  
Elastic Constants ◽  
Anisotropic Elastic

Elastic properties of grain boundaries in copper and their relationship to bulk elastic constants

1989 ◽  
Vol 40 (14) ◽  
pp. 9479-9484 ◽  
Author(s):  
James B. Adams ◽  
Wilhelm G. Wolfer ◽  
Stephen M. Foiles
Keyword(s):  
Grain Boundaries ◽  
Elastic Properties ◽  
Elastic Constants

scholarly journals High temperature and pressure effects on the elastic properties of B2 intermetallics AgRE

Open Physics ◽  
2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Lili Liu ◽  
Xiaozhi Wu ◽  
Weiguo Li ◽  
Rui Wang ◽  
Qing Liu
Keyword(s):  
High Temperature ◽  
Intermetallic Compounds ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Second Order ◽  
Pressure Effects ◽  
High Temperature And Pressure ◽  
Normal Behavior ◽  
Temperature And Pressure ◽  
Temperature And Pressure Effects

AbstractThe high temperature and pressure effects on the elastic properties of the AgRE (RE=Sc, Tm, Er, Dy, Tb) intermetallic compounds with B2 structure have been performed from first principle calculations. For the temperature range 0-1000 K, the second order elastic constants for all the AgRE intermetallic compounds follow a normal behavior: they decrease with increasing temperature. The pressure dependence of the second order elastic constants has been investigated on the basis of the third order elastic constants. Temperature and pressure dependent elastic anisotropic parameters A have been calculated based on the temperature and pressure dependent elastic constants.

ELASTIC PROPERTIES OF METAL SUPERLATTICES

1985 ◽  
Vol 56 ◽  
Author(s):  
A.F. JANKOWSKI ◽  
T. TSAKALAKOS
Keyword(s):  
Thin Film ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Vapor Deposition ◽  
Short Wavelength ◽  
Plastic Behavior ◽  
Average Composition ◽  
Strain Effects ◽  
Modulated Structure ◽  
Appreciable Increase

AbstractThe elastic properties of modulated structure materials are presented. An enhanced modulus effect has been observed in several composition modulated thin film systems containing short wavelength modulations.8-10nm. The foils were produced by vapor deposition using two or three source evaporator. As compared with homogeneous foils of the same average composition, the modulated foils exhibited an appreciable increase (up to 300%) in modulus. The dependence of various moduli on the modulation parameters (wavelength, composition and amplitude) are described. The plastic behavior, breaking and microhardness of these foils are also presented as a function of the modulation parameters. Current theories based on electronic and strain effects on the elastic constants of metals are also presented to explain the origin of the supermodulus effect.

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