Mutation Growth of Ice Crystal During Frost Formation

Frost formation on flat cold surfaces was experimentally investigated, particularly the dynamic process was visually observed. During test runs, a plastic film was used to separate the cold surface from moist air, and formation of ice crystals was observed using microscope visualization technique as the film was removed and the cold surface reached to a specified temperature. In crystal growth stage of frost formation, a new phenomenon was found during ice crystal growth process. A layer of irregular crystal embryos was formed at the earlier stage, and these crystal embryos vanished when ice crystals with regular form grew up along nicks on the plate. And then, ice crystals on the plate kept growing slowly, while the area without ice crystals kept clean. This process is divided into three stages: formation of crystal embryos, mutation of ice crystals, and growth of ice crystal. Duration times of the first two stages seemed to be constant for different cases.