Thermal Healing of Laser‐Induced Internal Cracks in Lithium Fluoride Crystals
作者:
Zhanyi Wang,
Yan Z. Li,
Martin P. Harmer,
Ye T. Chou,
期刊:
Journal of the American Ceramic Society
(WILEY Available online 1992)
卷期:
Volume 75,
issue 6
页码: 1596-1602
ISSN:0002-7820
年代: 1992
DOI:10.1111/j.1151-2916.1992.tb04231.x
出版商: Blackwell Publishing Ltd
关键词: lithium fluoride;cracks;heat treatment;kinetics;laser
数据来源: WILEY
摘要:
Laser‐induced internal cracks in LiF single crystals were annealed and healed at various temperatures in the absence of environmental contamination. The thermal healing process consists of three distinct stages: (a) pinching off of the crack into radially directed cylindrical pores within the rim of the crack front and within inner regions close to 〈110〉 directions, (b) ovulation of the 〈110〉 pores into rows of isolated, square‐shaped pores and, simultaneously, regression of the plate‐shaped subcracks situated near 〈100〉 directions, and (c) shrinkage of the isolated pores. A modified Arrhenius relationship between the rate of subcrack shrinkage and the annealing temperature was obtained. The apparent activation energy was found to be 2.0 eV (192.7 kJ/mol), suggesting that the healing process is controlled by
点击下载:
PDF
(843KB)
返 回