Heterogeneous Nucleation of Voids in Quenched Aluminum

Abstract

Aluminum of three different purities have been quenched in the atmospheres of hydrogen, carbon monoxide, dry air, wet air and vacuum, respectively, and secondary defects formed have been examined by electron microscopy. Voids are preferentially formed by quenching in atmospheres of hydrogen and wet air, while they are hardly formed in carbon monoxide, dry air and vacuum. These results are interpreted as the heterogeneous formation of all voids by dissolved hydrogen atoms. Discussions are given on the possibility of heterogeneous nucleation of voids, their formation mechanism and the effect of metallic impurities on the formation of voids. Previously published data of the void formation are reconsidered from the stand point of the heterogeneous nucleation of voids.