Properties of Mg laser alloyed with Al or AlSi20

Abstract

The alloyed surface layers were produced using thin Al or AlSi20 plates, which were first diffusion bonded and then melted into the Mg substrate. The microscopic analysis showed that alloying with Al led to the formation of an Al-enriched surface layer containing a high volume fraction of an Mg₁₇Al₁₂ phase. Applying AlSi20, on the other hand, resulted in the formation of an Al/Si-enriched layer containing Mg₂Si, Mg₂Al₃ and Mg₁₇Al₁₂ phases. The experimental results indicate that surface alloying of Mg with Al or AlSi20 using the presented method improved the properties of the material. The microhardness of the Al- and Al/Si-enriched layers was much higher than that of the substrate. Higher wear resistance was observed for the Al/Si-enriched layer. The alloyed layers provided a certain level of protection of Mg against corrosion. The specimens alloyed with Al showed better anticorrosive properties than those alloyed with AlSi20.

Keywords:

• Magnesium
• Laser alloying
• Intermetallic phases
• Microstructure
• Microhardness
• Wear resistance
• Corrosion resistance