Method and apparatus for preparing slurry specimens for cryo-scanning

Abstract

Cement slurries and similar compositions of matter may be examined by cryogenic scanning electron microscopy by preparing samples of slurries in small cylindrical specimen forming capsules which may be immersed in cryogenic fluid to freeze the cement slurries at different stages in hydration of the cement for analysis of the hydration process. The capsules are frangible so as to be able to easily remove the specimens after freezing whereupon the specimens are immersed in a cryogenic fluid and mounted in a specimen holder having cooperating support jaws which are operable from a point out of the cryogenic fluid to engage and retain the specimen on the holder. The holder is placed in a specimen preparation chamber which is maintained at a sufficiently low temperature and vacuum condition to minimize contamination of the specimen during preparation. The specimen preparation chamber is formed by a housing which includes a fracturing knife which is actuated after placement of the specimen in the chamber to fracture the specimen and expose an uncontaminated surface of the specimen for further preparation of the specimen for examination by scanning electron microscopy.