Porosity-dependence of elastic properties and ultrasonic velocity in polycrystalline alumina ? a model based on cylindrical pores

1996 ◽  
Vol 31 (1) ◽  
pp. 262-266 ◽  
Author(s):  
K. K. Phani
Keyword(s):  
Elastic Properties ◽  
Ultrasonic Velocity ◽  
Polycrystalline Alumina ◽  
Model Based ◽  
Porosity Dependence ◽  
Cylindrical Pores

Ultrasonic Characterization of the Elastic Constants in an Aging Ti-6Al-4V ELI Alloy

2019 ◽  
Author(s):  
Hector Carreon
Keyword(s):  
Elastic Properties ◽  
Ultrasonic Velocity ◽  
Precipitation Process ◽  
Material Microstructure ◽  
Clear Trend ◽  
Sem Image ◽  
Wave Velocities ◽  
Ultrasonic Characterization ◽  
Α Phase

Abstract In this paper, we report the experimental data of the elastic properties of the young and shear modulus based on the variation in the ultrasonic velocity parameter during the microstructural evolution in a Ti-6Al-4V alloy with two varying microstructures, bimodal and acicular respectively. The two different initial microstructures, were treated thermally by aging at 515°C, 545°C and 575°C at different times from 1 min to 576hr to induce a precipitation process. Ultrasonic measurements of shear and longitudinal wave velocities, scanning electron microscopy (SEM) image processing, optical microscopy (OM) and microhardness were performed, establishing a direct correlation with the measurements of the ultrasonic velocity and the elastic properties developed during the thermal treatment of the artificial aging. The results of the ultrasonic velocity show a very clear trend as the aging time progresses, which is affected by precipitation of Ti3Al particles inside the α phase. In this way, we can know, in a fast and efficient way, the elastic properties developed during the heat treatment of aging at long times, since the presence of these precipitates hardens the material microstructure affecting the final mechanical properties.

scholarly journals Micromechanical modeling of ultrasonic velocity for pore-structure and porosity characterization considering anisotropy in carbonate samples

2021 ◽  
Vol 60 (4) ◽  
pp. 294-319
Author(s):  
Joseline Mena-Negrete ◽  
Oscar C. Valdiviezo-Mijangos ◽  
Enrique Coconi-Morales ◽  
Rubén Nicolás-López
Keyword(s):  
Pore Structure ◽  
Elastic Properties ◽  
Ultrasonic Velocity ◽  
Compressional Wave ◽  
Micromechanical Modeling ◽  
Shear Wave Velocities ◽  
Aspect Ratios ◽  
Pore Types ◽  
Porosity Measurements ◽  
Wave Incidence

This work presents an approach to characterize the pore-structure and anisotropy in carbonate samples based on the Effective Medium Method (EMM). It considers a matrix with spheroidal inclusions which induce a transverse anisotropy. The compressional wave (VP), vertical (VSV)  and horizontal (VSH)  shear wave velocities are estimated taking into account parameters as characteristic length, frequency, angle of wave incidence, aspect ratio, mineralogy, and pore-filling fluid to predict pore shape in carbonates. Ranges of aspect ratios are shown to discriminate different pore types: intercrystalline, intergranular, moldic, and vuggy. The angle of wave incidence is a determinant parameter in the estimation of VP(0º, 45º, 90º), VSV(0º) and VSH(90º) to calculate dynamic anisotropic Young’s modulus (E33) and Poisson’s ratio (v31), as well as the Thomsen parameters, Epsilon, Gamma and Delta for quantification of the anisotropic pore-structure. The obtained results establish that the size, as well as the pore-structure, have a more significant impact on the elastic properties when the porosity takes values greater than 4% for the three frequencies, ultrasonic, sonic, and seismic. This investigation predicts the pore-structure and pore-size to improve characterization and elastic properties modeling of carbonate reservoirs. Validation of results includes porosity measurements and ultrasonic velocity data for different carbonate samples.

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