Abstract
In this research study, the effect of heat treatment on mechanical properties, and microstructure characteristics of magnesium alloy with 99.94 % magnesium was studied. The heat treatment of samples was conducted at 150 ⁰C, 300 ⁰C, and 450 ⁰C for 2 hours. The samples were characterized by microstructure characterization using optical microscope (OEM) by observing the evolution of the microstructure of the heat-treated magnesium alloy. The hardness test was done on the surface of each sample using the load of 50 N to show the effect of heat treatment on the cross-section surface of magnesium alloy. From the results, the average grain sizes of the materials are different due to the different heat treatment and cooling rate of the materials.it is found that the hardness of the surface of the samples is higher at the edges of the samples than in the middle. The changes in average hardness of magnesium with the increase in temperature is due to an increase in grain size.