Rigorous Metallogrpahic Technique for the Examination of Cast and Homogenized 6xxx Log Cross Sections

摘要

Comprehensive examination of cast and homogenized log quality generally requires microstructural evaluation. This can, of course, be a tedious and inexact process, often involving rather extensive metal cutting, or gross appraisals by way of "macro-etching." Using advanced lapping, polishing and micro-and macro-etching techniques, Rensselaer has established comparatively economical capabilities for rigorous microstructural evaluation on the entire log cross-section. This paper outlines these techniques in detail, as applied to logs in the 15 to 23 cm diameter range. Microstructural representations of dendrite structure, surface and near-surface anomalies, and precipitate distributions are presented. Emphasis is placed on radial variations in structure, best seen with a complete log section.