Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics

Indentation size effect (ISE) and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics are investigated using micro-indentation and indentation-strength (IS) techniques, respectively. Vickers micro-indentations were applied on both materials at the load of 0.10–19.6 N to determine the load i...

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Main Authors: Alao, Abdur-Rasheed, Azmir, Azhari
Format: Article
Language:English
English
Published: Elsevier Ltd. 2021
Subjects:
Online Access:http://umpir.ump.edu.my/id/eprint/32457/1/Investigation%20of%20indentation%20size%20effect%20and%20R-curve%20behaviour_FULL.pdf
http://umpir.ump.edu.my/id/eprint/32457/2/Investigation%20of%20indentation%20size%20effect%20and%20R-curve%20behaviour%20.pdf
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author Alao, Abdur-Rasheed
Azmir, Azhari
author_facet Alao, Abdur-Rasheed
Azmir, Azhari
author_sort Alao, Abdur-Rasheed
collection UMP
description Indentation size effect (ISE) and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics are investigated using micro-indentation and indentation-strength (IS) techniques, respectively. Vickers micro-indentations were applied on both materials at the load of 0.10–19.6 N to determine the load influence on the measured hardness. For the IS-measured fracture toughness, the load ranged from 1.96 to 19.6 N. The hardness decreased with increasing load by 20% and 18% on Li2O–SiO2 and Li2O–2SiO2 glass ceramics, respectively, indicating the ISE behaviour on both materials. The fracture toughness increased with the load by 27% and 59% on Li2O–SiO2 and Li2O–2SiO2 glass ceramics, respectively, signifying the R-curve behaviour. The ISE behaviour of both materials was analysed using the Meyer's, Hays–Kendall (HK), proportional specimen resistance (PSR), Nix–Gao (NG), modified PSR (MPSR) and elastic plastic deformation (EPD) models while the R-curve behaviour was analysed by the fractional power law. The Meyer's index of both materials was less than 2, strongly confirming the ISE existence. The HK, PSR and NG models were only suitable to determine intrinsic Vickers hardness for Li2O–2SiO2 glass ceramic while the MPSR and EPD models were successful for both materials. The fractional power law gave higher R-curve steepness for Li2O–2SiO2 than Li2O–SiO2 glass ceramics. Also, material and brittleness indices predicted, respectively, higher quasi-plasticity and better machinability for Li2O–2SiO2 than Li2O–SiO2 glass ceramics indicating superior performance in the former to the latter. Finally, this study presents a new significant insight into the micro-mechanisms of fracture tolerance behaviour of these glass ceramics which is critical to their functional performance as structural ceramics.
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spelling UMPir324572021-11-08T02:34:57Z http://umpir.ump.edu.my/id/eprint/32457/ Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics Alao, Abdur-Rasheed Azmir, Azhari TS Manufactures Indentation size effect (ISE) and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics are investigated using micro-indentation and indentation-strength (IS) techniques, respectively. Vickers micro-indentations were applied on both materials at the load of 0.10–19.6 N to determine the load influence on the measured hardness. For the IS-measured fracture toughness, the load ranged from 1.96 to 19.6 N. The hardness decreased with increasing load by 20% and 18% on Li2O–SiO2 and Li2O–2SiO2 glass ceramics, respectively, indicating the ISE behaviour on both materials. The fracture toughness increased with the load by 27% and 59% on Li2O–SiO2 and Li2O–2SiO2 glass ceramics, respectively, signifying the R-curve behaviour. The ISE behaviour of both materials was analysed using the Meyer's, Hays–Kendall (HK), proportional specimen resistance (PSR), Nix–Gao (NG), modified PSR (MPSR) and elastic plastic deformation (EPD) models while the R-curve behaviour was analysed by the fractional power law. The Meyer's index of both materials was less than 2, strongly confirming the ISE existence. The HK, PSR and NG models were only suitable to determine intrinsic Vickers hardness for Li2O–2SiO2 glass ceramic while the MPSR and EPD models were successful for both materials. The fractional power law gave higher R-curve steepness for Li2O–2SiO2 than Li2O–SiO2 glass ceramics. Also, material and brittleness indices predicted, respectively, higher quasi-plasticity and better machinability for Li2O–2SiO2 than Li2O–SiO2 glass ceramics indicating superior performance in the former to the latter. Finally, this study presents a new significant insight into the micro-mechanisms of fracture tolerance behaviour of these glass ceramics which is critical to their functional performance as structural ceramics. Elsevier Ltd. 2021-12 Article PeerReviewed pdf en http://umpir.ump.edu.my/id/eprint/32457/1/Investigation%20of%20indentation%20size%20effect%20and%20R-curve%20behaviour_FULL.pdf pdf en http://umpir.ump.edu.my/id/eprint/32457/2/Investigation%20of%20indentation%20size%20effect%20and%20R-curve%20behaviour%20.pdf Alao, Abdur-Rasheed and Azmir, Azhari (2021) Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics. Journal of the Mechanical Behavior of Biomedical Materials, 124 (104842). pp. 1-13. ISSN 1751-6161. (Published) https://doi.org/10.1016/j.jmbbm.2021.104842 https://doi.org/10.1016/j.jmbbm.2021.104842
spellingShingle TS Manufactures
Alao, Abdur-Rasheed
Azmir, Azhari
Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics
title Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics
title_full Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics
title_fullStr Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics
title_full_unstemmed Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics
title_short Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics
title_sort investigation of indentation size effect and r curve behaviour of li2o sio2 and li2o 2sio2 glass ceramics
topic TS Manufactures
url http://umpir.ump.edu.my/id/eprint/32457/1/Investigation%20of%20indentation%20size%20effect%20and%20R-curve%20behaviour_FULL.pdf
http://umpir.ump.edu.my/id/eprint/32457/2/Investigation%20of%20indentation%20size%20effect%20and%20R-curve%20behaviour%20.pdf
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