New Magnesium Composite with Mg₁₇Al₁₂ Intermetallic Particles 

Abstract

Although magnesium is one of the materials with the lowest density, its application is limited amongst other commercial materials due to insufficient strength. Generally, the strength of magnesium can be increased by introducing the Mg₁₇Al₁₂ phase into the structure with the addition of aluminum. In this study, as a different approach, Mg₁₇Al₁₂ particles were added to pure magnesium to form a composite structure. For this purpose, Mg composites with different Mg₁₇Al₁₂ contents were fabricated by powder metallurgy methods. Pure Mg and Mg₁₇Al₁₂ particles were mixed in a vacuum ball milling equipment for 1 h using zirconia balls to obtain the Mg metal matrix composite with homogeneously distributed intermetallic reinforcements. While for pure Mg powders, the sintering temperature was selected as 600 °C, for Mg + Mg₁₇Al₁₂ mixtures, it was 420 °C due to the eutectic transformation between Mg and Al. The sintering time and pressure of the Mg-based mixtures were held constant for 30 min and 50 MPa, respectively. All sintering processes were carried out under a 10^–2 Pa vacuum atmosphere. Microstructural characterization was performed using optical microscopy and scanning electron microscopy. The hardness and wear properties of the composites produced have also been studied. The hardness and wear resistance of composites increased significantly as the Mg₁₇Al₁₂ particle content increased. Although the particle-enhanced composite density increased from 1.72 to 1.92 g/cm³, a 2.4-fold increase in hardness and a two-fold increase in wear resistance was observed. This magnesium composite produced with a new design could be used in many different areas.