Microstructure and Tensile Properties of Graphene-Oxide-Reinforced High-Temperature Titanium-Alloy-Matrix Composites

Abstract

In this study, graphene-oxide (GO)-reinforced Ti–Al–Sn–Zr–Mo–Nb–Si high-temperature titanium-alloy-matrix composites were fabricated by powder metallurgy. The mixed powders with well-dispersed GO sheets were obtained by temperature-controlled solution mixing, in which GO sheets adsorb on the surface of titanium alloy particles. Vacuum deoxygenating was applied to remove the oxygen-containing groups in GO, in order to reduce the introduction of oxygen. The compact composites with refined equiaxed and lamellar α phase structures were prepared by hot isostatic pressing (HIP). The results show that in-situ TiC layers form on the surface of GO and GO promotes the precipitation of hexagonal (TiZr)6Si3 particles. The composites exhibit significant improvement in strength and microhardness. The room-temperature tensile strength, yield strength and microhardness of the composite added with 0.3 wt% GO are 9%, 15% and 27% higher than the matrix titanium alloy without GO, respectively, and the tensile strength and yield strength at 600 °C are 3% and 21% higher than the matrix alloy. The quantitative analysis indicates that the main strengthening mechanisms are load transfer strengthening, grain refinement and (TiZr)6Si3 s phase strengthening, which accounted for 48%, 30% and 16% of the improvement of room-temperature yield strength, respectively.

Microstructural and Mechanical Properties Characterization of Graphene Oxide-Reinforced Ti-Matrix Composites

“…Combined with the analysis of XRD results, it is judged that this is TiC generated by the reaction of GO and Ti. Similar results have been reported [30,31].…”

Microstructural and Mechanical Behavior Investigations of Nb-Reinforced Mg–Sn–Al–Zn–Mn Matrix Magnesium Composites

“…The lower relative density values in highly reinforced samples suggest that achieving a denser packing of particles becomes more challenging as the reinforcement content increases. Literature studies frequently indicate that a relative density value exceeding 95% for materials produced through powder metallurgy signifies the successful implementation of the sintering process [77,78]. Interestingly, in the present study, the relative density value of the TAZ532 matrix alloy surpasses 99%.…”

“…The increased Nb reinforcement ratio in the composites contributes to the positive development of the tensile strength properties. The reinforcing particles, which possess a higher strength compared to the matrix alloy, effectively hinder dislocation movement and promote load transfer within the material during tensile loading [78]. A noticeable trend is observed in the results, where the microhardness values consistently increase with the addition of Nb at different weight ratios.…”

“…This observation suggests that, while the Nb reinforcement enhances strength, there may be a trade-off with the material's ductility beyond a certain threshold.The increased Nb reinforcement ratio in the composites contributes to the positive development of the tensile strength properties. The reinforcing particles, which possess a higher strength compared to the matrix alloy, effectively hinder dislocation movement and promote load transfer within the material during tensile loading[78].…”

Microstructure and Mechanical Properties of Magnesium Matrix Composites Reinforced by In Situ Reduced Graphene Oxide

“…Therefore, the morphology of the GO under SEM is blurred (shown in Figure 3 a). The individual GO sheet is found to have a width of 30–70 μm, which is much larger than that of other metal matrix composites [ 31 , 32 , 33 ]. From Figure 4 d we can see that the GO is transparent and slightly aggregated, with the wrinkles loosely distributed on the surface.…”