Excellent corrosion resistance and hardness in Al alloys by extended solid solubility and nanocrystalline structure

Abstract

Development of ultra-high strength and corrosion-resistant aluminum (Al) alloys is demonstrated by a combination of suitable alloying elements and processing technology able to cause extended solid solubility and nanocrystalline structure. Binary Al-transition metal (M: Cr, Ni, Mo, Si, Ti, Mn, V, Nb) alloys, produced by high-energy ball milling and subsequent cold compaction, have exhibited significantly high hardness and corrosion resistance compared to any commercial Al alloy. The cyclic potentiodynamic polarization tests revealed a significant improvement in pitting and repassivation potentials. X-ray diffraction analysis revealed the grain refinement <100nm and extended solid solubility. IMPACT STATEMENT High-energy ball-milled Al alloys, owing to excellent corrosion resistance and high hardness, are expected to be a new class of Al alloys and initiate a multidisciplinary research direction.