Magnesium-based nanocomposites developed through multi-pass friction stir processing and strengthening mechanisms exploration Entwicklung von magnesiumbasierten Nanoverbundwerkstoffen durch einen mehrstufigen Rührreibschweißprozess und Erforschung der Verfestigungsmechanismen

Abstract

In the current experimental work, using secondary phase hard nano titanium carbide (TiC) particles as reinforcement, two different magnesium metal matrices i. e., AZ31B/TiC and AZ61 A/TiC composite materials were synthesized by friction stir processing. Using the traditional testing approach for the developed materials, the simultaneous gain in metallurgical, mechanical, electrical, and tribological characteristics compared to the base substrate was examined. The microstructure study results for AZ31B/TiC and AZ61 A/TiC composites showed a uniform distribution of reinforced particles as well as an evolution in grain size, from 82 μm to 4.2 μm and from 74 μm to 3.7 μm, respectively, which consequently contribute in a significant gain in the microhardness of both composites i. e., around 2.2 times and 2.67 times respectively, greater than the base metal. When compared to monolithic alloys, the synthesized AZ31B/TiC and AZ61 A/TiC composites showed improvements in the areas of tensile strength, compressive strength, and coefficient of friction up to 1.81 times, and 1.64 times, 1.74 times and 1.58 times, and 57.92 % and 58.47 %, respectively. Furthermore, these improvements in characteristics also increase the final strengthening of the nanocomposite and reduce electrical conductivity.