The Surface Energy of {100} Potassium Chloride
Abstract
A modified Obreimov-Gilman cleavage technique utilizing the apparent variation of cleavage sur face energy with crack length and specimen di mensions has been used to determine the true sur face energy of the planes of potassium chloride at room temperature. The true surface energy of KCl was found to be 110 = 5 ergs/cm2, in good agreement with Born and Stern's theoretical estimation but not with more recent estimates of this quantity. Possible causes for this dis crepancy are discussed. Other experiments re vealed that the presence of a solvent environ ment at the crack tip increased the cleavage fracture energy of potassium chloride only some two or three times. This suggests that the Gurney-Pulliam phenomenon of precipitation at a crack tip is not primarily responsible for the increased strength and ductility observed when certain ionic crystals are tested in solvent environments (Joffe's effect).
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1963
- Accession Number
- AD0409566
Entities
People
- A. R. Westwood
- T. T. Hitch
Organizations
- Martin Marietta