Wear Behavior and Microstructure of Mg-Sn Alloy Processed by Equal Channel Angular Extrusion

Area of Science:

• Materials Science
• Mechanical Engineering
• Metallurgy

Background:

• Magnesium-tin (Mg-Sn) alloys are crucial for portable electronics and automotive applications due to their lightweight properties.
• Understanding the mechanical behavior of Mg-Sn alloys under processing is vital for optimizing their performance.

Purpose of the Study:

• To characterize the mechanical properties, specifically hardness and wear behavior, of Mg-5wt.% Sn alloy after Equal Channel Angular Extrusion (ECAE).
• To investigate the influence of ECAE processing on the microstructure and its correlation with mechanical performance.

Main Methods:

• Vickers hardness testing and pin-on-disc wear testing were employed to evaluate mechanical properties.
• Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used for microstructural analysis.
• The study involved processing Mg-Sn alloy through multiple passes of ECAE.

Main Results:

• ECAE significantly refined the grain size of Mg-Sn alloy, decreasing it from 117.6 μm (as-cast) to 24.4 μm (four passes).
• Hardness of the alloy improved substantially with ECAE processing.
• Maximum wear resistance of 73.77 m/mm³ was observed after one ECAE pass, linked to grain refinement and Mg₂Sn precipitation.

Conclusions:

• Grain refinement through ECAE enhances the hardness and wear resistance of Mg-Sn alloys.
• While single-pass ECAE improves wear resistance, multi-pass processing can lead to increased oxidative and abrasive wear due to higher internal energy and oxide debris formation.
• The study highlights the trade-offs in optimizing Mg-Sn alloy performance through ECAE, balancing grain refinement benefits against increased oxidation in multi-pass treatments.