Microstructure, mechanical properties and damping capacity of Fe-Mn-Co Alloys reinforced with graphene

Fe-17Mn-3Co-xGR alloys (x = 0,0.5,1,1.5 wt%) reinforced with Graphene were systematically characterized and analyzed to investigate effect of Graphene on microstructure, mechanical properties, and damping capacity of the composites. With the increase of Graphene content, the grain size of the alloys gradually decreases while the hardness, tensile strength, and fracture elongation gradually increase. When Graphene content was 1.5 wt%, the tensile strength, fracture elongation, and hardness of the alloy were 438.8 MPa, 11.1 %, and 392.9 HV respectively, which increased by 72.3 %, 101.1 %, and 45.1 % compared to the alloy without Graphene. Results show that the alloy is mainly composed of γ-austenite, ε-martensite, and α՛-martensite, simultaneously, the carbides of Fe and the carbides of Mn are formed at the grain boundaries. As the Graphene content increases, the carbides formed at the grain boundaries gradually increase to the extent that reunion even occurs. The damping capacity increases and then decreases with an increased Graphene content, which is mainly related to the grain boundary damping effect because of grain size reduction, the interfacial damping effect owing to carbide formation, and the dislocation damping effect. When the Graphene content is 1 wt %, the carbide formation suppresses the grain growth and the carbide reunion is useless, the alloy has the most excellent damping performance with a damping capacity of 0.033 and favorable mechanical properties. Therefore, 1 wt % Graphene addition to Fe-17Mn-3Co alloy can obtain Fe-17Mn-3Co-1GR damping alloy with the optimal overall properties.