Contribution of interferometry to Vickers indentation toughness determination of glass and ceramic glass

Mohamed Bentoumi; Ahmed Mdarhri; Habib Benzaama; Alain Iost; Didier Chicot

doi:10.1117/1.OE.58.3.034102

6 March 2019 Contribution of interferometry to Vickers indentation toughness determination of glass and ceramic glass

Mohamed Bentoumi, Ahmed Mdarhri, Habib Benzaama, Alain Iost, Didier Chicot

Author Affiliations +

Optical Engineering, Vol. 58, Issue 3, 034102 (March 2019). https://doi.org/10.1117/1.OE.58.3.034102

Abstract

Cracking resistance or fracture toughness of brittle materials, such as optical glasses, can be determined by Vickers indentation, which allows generating cracks along the diagonals of the indent whose length depends of the loading rate. Subsequently, a relationship between the crack length and the corresponding indentation load is applied to calculate the indentation fracture toughness. As a result, the precision of the fracture toughness will depend on the accuracy of the crack length measurement. To minimize the uncertainties of this parameter, we propose its measurement more precisely by a profilometric method. On the other hand, as the glass surface roughness is recognized to have an important influence on the crack growth, different surface preparations are studied to minimize this roughness effect. In this work, four types of glasses are studied, namely Classical Crown K5, Borosilicate Crown BK7, Dense Flint SF2, and Ceramic Zerodur^® glasses. The surface polishing is performed by using CeO₂ pellets, which allow obtaining a roughness value for R_a to be <10 nm. Vickers instrumented indentation tests, allowing the plot of the applied load as a function of the indenter displacement, are performed with various maximum applied loads of up to 90 N. Different relationships based on assumptions on the crack shape (half-penny/median or Palmqvist cracks) are then used to calculate the indentation fracture toughness. Additionally, to accurately measure the crack length, we present an original approach based on the analysis of the interferometry map obtained with an optical profilometer using a monochromatic wavelength.

Citation Download Citation

Mohamed Bentoumi, Ahmed Mdarhri, Habib Benzaama, Alain Iost, and Didier Chicot "Contribution of interferometry to Vickers indentation toughness determination of glass and ceramic glass," Optical Engineering 58(3), 034102 (6 March 2019). https://doi.org/10.1117/1.OE.58.3.034102

Received: 3 October 2018; Accepted: 5 February 2019; Published: 6 March 2019

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

;

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE