Effect of humidity on indentation crack growth in lead-free ferroelectric ceramics

H. J. Zhang; J. X. Li; W. Y. Chu; Y. J. Su; L. J. Qiao

doi:10.1117/12.841403

20 October 2009 Effect of humidity on indentation crack growth in lead-free ferroelectric ceramics

H. J. Zhang, J. X. Li, W. Y. Chu, Y. J. Su, L. J. Qiao

Proceedings Volume 7493, Second International Conference on Smart Materials and Nanotechnology in Engineering; 74935I (2009) https://doi.org/10.1117/12.841403
Event: Second International Conference on Smart Materials and Nanotechnology in Engineering, 2009, Weihai, China

Abstract

The effect of humidity on growth of unloaded indentation crack in KNN free-lead ferroelectric ceramics has been investigated. The results showed that crack growth of unloaded indentation in lead-free ferroelectric ceramics could occur in humid air of 70% and 90%RH without electric field and mechanical stresses, but did not in air with RH≤30%. The growth of indentation crack could occur in dry air when the field was larger than the threshold field E_th(y)=0.01E_C (normal to the poling direction) or E_th(z)=0.05E_C (parallel to the poling direction) and the larger the field, the shorter the incubation time. The increment of crack growth in humid air under sustained field, Δc, was composed of three parts, i.e., Δc=Δc₁ + Δc₂ + Δc₁₂, where Δc₁ was the increment in humid air without field, Δc₂ that in dry air under sustained field and Δc₁₂ that induced by combined effect of electric field and humidity because of humidity promoting domain switching. Crack growth of unloaded indentation could occur during hydrogen charging and the threshold stress intensity factor of hydrogen-induced delayed cracking, KIH, as well as the fracture toughness of hydrogenated ceramics, KIC(H), decreased with increasing hydrogen concentration.

Citation Download Citation

H. J. Zhang, J. X. Li, W. Y. Chu, Y. J. Su, and L. J. Qiao "Effect of humidity on indentation crack growth in lead-free ferroelectric ceramics", Proc. SPIE 7493, Second International Conference on Smart Materials and Nanotechnology in Engineering, 74935I (20 October 2009); https://doi.org/10.1117/12.841403

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

Includes PDF, HTML & Video, when available