Microstructure characterization of ZK60 magnesium alloys using TEM and HR-EBSD

Area of Science:

• Materials Science
• Metallurgy
• Mechanical Engineering

Background:

• Magnesium alloys, like ZK60 (Mg-Zn-Zr), are crucial for lightweight applications.
• Precipitate evolution during aging significantly impacts alloy properties.
• Understanding deformation mechanisms is vital for optimizing alloy performance.

Purpose of the Study:

• To investigate the microstructural and textural evolution of ZK60 alloys under indentation.
• To analyze the dominant deformation mechanisms (twinning and slip) in different aging states (T4 and T6).
• To correlate microstructure evolution with mechanical response.

Main Methods:

• Microindentation tests on T4 and T6 aged ZK60 alloys.
• Electron Backscatter Diffraction (EBSD) for microstructure and texture analysis.
• Uniaxial compression tests to examine strain-induced evolution.

Main Results:

• Twinning, primarily tensile twinning with two variants, was observed near indentation marks.
• Deformation mechanisms varied with initial grain orientation.
• Nonbasal oriented grains showed twinning followed by slip, while basal oriented grains exhibited only slip.

Conclusions:

• Deformation in ZK60 alloys is a complex interplay of twinning and slip.
• Aging state (T4 vs. T6) influences precipitate behavior and thus mechanical response.
• Grain orientation dictates the predominant deformation pathway, impacting texture evolution.