An investigation of microstructure evolution of RAP processed ZK60 magnesium alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2009-02, Vol.501 (1), p.146-152
• Main Authors: Luo, Shoujing, Chen, Qiang, Zhao, Zude
• Format: Article
• Language: English
• Subjects: Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Magnesium alloys; Materials science; Microstructure; Physics; RAP; Semi-solid state; Treatment of materials and its effects on microstructure and properties
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2008.09.059

The effect of compression ratio on the microstructure evolution of semi-solid ZK60 magnesium alloy produced by the recrystallisation and partial melting (RAP) process was investigated. The microstructure evolution within the semi-solid zone of a ZK60 alloy through a direct isothermal holding process from as-received and as-deformed conditions was also investigated. The results show that as-received alloys reheated to the semi-solid state had solid particles predominantly elongated along original extrusion direction. For as-deformed alloys, the compression deformation gradually refined the recrystallised α-Mg grains by increasing their nucleation to growth ratio. During isothermal holding, intragranular liquid droplets were present in a large number of solid particles, reducing in number and increasing in average size with increasing holding time. The coarsening behavior of solid particles in the semi-solid state obeyed an Ostwald ripening mechanism. The coarsening rate constant obtained was 556 μm 3s −1 at 590 °C.