Dehydration of potassium alum induced by shock loading

18th APS-SCCM; 24th AIRAPT

Kishimura, H.^1 ; Imasu, Y.^1 ; Matsumoto, H.^1

Department of Materials Science and Engineering, National Defense Academy, 1-10-20 Hashirimizu, Kanagawa, Yokosuka

239-8686, Japan^1

关键词: Amorphous phase;    Copper containers;    Irreversible phase;    Potassium alum;    Sample surface;    Shock compressions;    Shock loadings;    Water molecule;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/18/182020/pdf
DOI  :  10.1088/1742-6596/500/18/182020

来源: IOP

【 摘 要 】

Potassium alum (KAl(SO4)2·12H2O) powder filled into a copper container were shock loaded up to 6.3 GPa by flyer plate impact. Recovered samples were characterized by X-ray diffraction (XRD) analysis, Raman spectroscopy, and scanning electron microscopy (SEM). XRD and Raman results of samples shocked at 4.4 GPa and below indicated that there was no sign of phase transition. In contrast, the XRD pattern of the sample shocked at 6.3 GPa was clearly different from the initial sample. Unlike previous results obtained from hydrostatic pressure experiments, an irreversible phase transition to an amorphous phase occurred under shock compression at 6.3 GPa. The morphology of the sample surface indicated the ejection of water vapor caused by shock loading. The amorphization may be attributed to the vaporization of water molecules caused by shock pressure and shock-induced heat.