Inclusion Assessment in Magnesium and Magnesium Base Alloys

Inclusion types and methods for inclusion assessment in magnesium and magnesium base alloys are reviewed. In pure magnesium oxides are the dominating inclusion type, while in alloys e.g. AM60 and AZ91D intermetallic particles may be equally dominant. Inclusion assessment may consist of sampling, followed by quantitative microscopy of parts of the sample, giving number size distributions and/or total contents of each particle type. In refined metal it is difficult to obtain results with statistical significance unless inclusions from a large volume are preconcentrated. In a recent method reflected light from a fracture sample is examined and inclusion content is represented by a number only. Emerging technologies include adaption of LiMCA to magnesium. No methods satisfy requirements related to rapid response, ability to distinguish between particle types, satisfactory resolution, large sample size and low cost.