Methodology for the Quantitative Evaluation of the Structure in Cast Magnesium Alloys

Magnesium alloys with alkaline earth elements are attractive materials for components working at elevated temperature (ca. 180 °C) in the automotive industry. It is well known that properties of engineering materials depends on the microstructure. Therefore, complex procedures for the quantitative description of the microstructure, which enable to obtain repeatable and unequivocal results, are very important in process control of technology parameters as well as to determine the relationship between properties and microstructure of materials. This chapter presents a comprehensive procedure consistent with modern quality assurance systems for the quantitative assessment of primary grains and intermetallic compounds in magnesium alloys containing aluminum and strontium. The presented procedure for this alloy includes: a methodology of metallographic specimens preparation, a methodology of image acquisition with light microscopy and finally automatic image analysis operations sequence enabling detection of grain boundaries and intermetallic compounds. Moreover, the procedure contains guidelines for statistical analysis which allows for an objective interpretation of results.