X-ray diffraction analysis and williamson-hall method in usdm model for estimating more accurate values of stress-strain of unit cell and super cells (2 × 2 × 2) of hydroxyapatite, confirmed by ultrasonic pulse-echo test

Rabiei, M ; Sharif University of Technology | 2021

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  1. Type of Document: Article
  2. DOI: 10.3390/ma14112949
  3. Publisher: MDPI AG , 2021
  4. Abstract:
  5. Taking into account X-ray diffraction, one of the well-known methods for calculating the stress-strain of crystals is Williamson-Hall (W–H). The W-H method has three models, namely (1) Uniform deformation model (UDM); (2) Uniform stress deformation model (USDM); and (3) Uniform deformation energy density model (UDEDM). The USDM and UDEDM models are directly related to the modulus of elasticity (E). Young’s modulus is a key parameter in engineering design and materials development. Young’s modulus is considered in USDM and UDEDM models, but in all previous studies, researchers used the average values of Young’s modulus or they calculated Young’s modulus only for a sharp peak of an XRD pattern or they extracted Young’s modulus from the literature. Therefore, these values are not representative of all peaks derived from X-ray diffrac-tion; as a result, these values are not estimated with high accuracy. Nevertheless, in the current study, the W-H method is used considering the all diffracted planes of the unit cell and super cells (2 × 2 × 2) of Hydroxyapatite (HA), and a new method with the high accuracy of the W-H method in the USDM model is presented to calculate stress (σ) and strain (ε). The accounting for the planar density of atoms is the novelty of this work. Furthermore, the ultrasonic pulse-echo test is per-formed for the validation of the novelty assumptions. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
  6. Keywords:
  7. Cells ; Cytology ; Deformation ; Hydroxyapatite ; X ray powder diffraction ; Average values ; Engineering design ; High-accuracy ; Materials development ; Ultrasonic pulse ; Uniform deformation ; Uniform stress ; Williamson-Hall ; Ultrasonic testing
  8. Source: Materials ; Volume 14, Issue 11 , 2021 ; 19961944 (ISSN)
  9. URL: https://www.mdpi.com/1996-1944/14/11/2949