This paper evaluates the micro-hardness and corrosion behavior of friction stir processed AZ91D magnesium alloy in the process of effecting fine grained structure. The yield strength, ultimate tensile strength, percentage of elongation of the base mental being cast along AZ91D of 12 mm thickness are analyzed the through tensile behavior and micro hardness properties and are studied and compared with the processed material of the same alloy composition. Scanning electron microscope was employed to analyze the microstructure of the studied alloys. The study further contrasts the tensile properties and micro hardness properties at the cross section of the base metal and the processed fine gained materials. The micro structural analysis is carried using optical metallographic and scanning electron microscope and the fine grained friction stir processed AZ91D magnesium alloy is further processed for equal channel angular pressing. The angular pressing method is exclusively used to carry out study of the corrosion behavior of material. © 2016 Elsevier B.V., All rights reserved.