THE ATTACK OF ZINC MONOCRYSTALS BY STRONG ACIDS AND SURFACE DISINTEGRATION OF THE DISSOLVING METAL
Abstract
The attack of Zn monocrystals by acids (HCl, H2SO4, HClO4 and HNO3) was studied. Crystals of high purity (99.999+%) as well as those containing small amounts (0.01 to 0.05% by weight) of Al, Mg and Au were used. The crystal planes behaved very similarly in the first 3 acids: the (0001) planes were attacked perpendicularly, the dissolution process penetrated to a depth of 4 to 8 microns, then spread laterally, followed by renewed penetration. In more concentrated acids the bottom of the etch pits became smooth, resisting further attack of the acid, before the next layer was penetrated. Branched, very fine material, consisting of pure Zn remained at some sites in the form of elevations (surface disintegration). The attack of the (1010) plane in dilute acids occurred by penetration into the depth between several basal planes. Irregular etch pits were formed. In more concentrated acids, the (1010) plane shifted parallel to itself. The attack of the pyramidal planes was similar. Strong HNO3 worked like an electropolisher. An explanation of the various dissolution phenomena is given.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1965
- Accession Number
- AD0473137
Entities
People
- M. E. Straumanis
- Yaonan Wang