Papers by Keyword: Ca Content

Abstract: Magnesium (Mg) has a great potential to be used in various field of work since it is lightweight and has low density properties. However, its application is limited due to its poor properties for Mg has a relatively low strength. Improvement is made by mixing Mg with calcium (Ca) as composite element for it is lightweight and non-toxic. In this research, Mg is prepared with different weight percentage (0, 0.5, 1, 1.5, 2 wt. %) of Ca with pure Mg as reference prepared by powder metallurgy (PM) method to study the mechanical properties. Morphological analysis carried out by optical microscope shows increase grain refinement with the increase of calcium content in Mg-Ca composites. The phase transition upon addition of Ca is determined using XRD method detects formation of Mg₂Ca. Range from 1.78 g/cm³ to 1.83 g/cm³, the density of each sample composite increase. While porosity profiles show inverse characteristics upon addition of Ca. Microhardness strengths also intensifies up to 193.20 MPa as more Ca content added in.

Abstract: Having the benefit of lightweight and low density makes magnesium (Mg) a good element with high potential to be used in various field of work. Yet, its application is limited for Mg is relatively low in term of strength. Hence, calcium (Ca) is chosen to be mixed with Mg as additional element for it is lightweight and non-toxic. In this research, Mg is prepared with different weight percentage (0, 1, 2 wt. %) of Ca via powder metallurgy (PM) method. The effect of sintering was investigated by focusing on the microstructure and properties of sintered sample. The samples were sintered at two sintering temperature (500 and 600 °C) in argon atmosphere. Morphological analysis carried out by optical microscope shows increase pores refinement with the increase of sintering temperature together with calcium content in Mg-Ca composites. Results show that the grain size and hardness of the samples increase as sintering temperature increase.

Abstract: The effect of Ca and Sr content on the microstructure and mechanical properties of a cast AZ91 magnesium alloy is investigated. Ca and Sr additions in AZ91 magnesium alloy are expected high creep resistance. The microstructure of the alloy exhibits the dendritic α-matrix and the second-phases forming networks on the grain boundary. Tensile tests at elevated temperatures between 448 and 523K reveal that the creep resistance was improved with increasing the additional amount of Ca, especially more than 1.0wt%. From the perspective of grain refinement effect, it is expected that the additions of Ca and Sr to AZ91 magnesium alloy not only improve creep resistance but also improve mechanical properties at room temperature.