Microstructural Evolution and Mechanical Properties of Multiwall Carbon Nanotubes Reinforced Titanium-Based Nanocomposites Developed by Spark Plasma Sintering

Abstract

In this study, the role of multiwall carbon nanotubes (MWCNT) on the microstructural evolution and mechanical properties of Ti6Al4V-based composites was investigated. This was conducted by dispersing different concentrations (0.5, 1.0 and 1.5 wt%) of MWCNT into the Ti6Al4V matrix using shift-speed ball milling technique. Thereafter, the Ti6Al4V and the nanocomposites were consolidated via the spark plasma sintering technique. Various characterization techniques; scanning electron microscopy (SEM), transmission electron microscopy (TEM) and light microscopy were conducted to understand the microstructural evolution of the samples after the dispersion and sintering process. Subsequently, micromechanical and nanoindentation was carried out to reveal the mechanical properties of the fabricated samples. The morphological examination using SEM and TEM revealed the dispersibility of MWCNT dispersed within the Ti6Al4V matrix. Besides, the selected area diffraction and the fast Fourier Transform pattern demonstrated that the increase in concentration of the MWCNT exposed the nanotubes to adverse stresses during the dispersion process. Furthermore, the incorporation and increase in concentration of the MWCNT in the titanium alloy resulted in microstructural and phase changes, which translate to tremendous improvements in microhardness, nanohardness and elastic modulus up to 46.9%, 150.8%, and 169.5% respectively.

Membranes of Multiwall Carbon Nanotubes in Chitosan–Starch with Mechanical and Compositional Properties Useful in Li-Ion Batteries

“…By analyzing two areas of these MWOHs micrographs with FFT, both display more diffuse spots, and the line scan shows a rather poor crystallinity, revealed by the wide peaks and low intensity of the central spot. This is a characteristic of defective CNTs exhibiting distorted layers [59,112], confirming the oxidation of the multiwall carbon nanotubes. HRTEM micrographs and ED patterns of RLi and SLi are shown in Figure 7.…”

Grain Refinement and Mechanical Enhancement of Titanium Matrix Composites with Nickel-Coated Graphene Nanoflakes: Influence of Particle-Size Mismatch

“…This transformation plays a vital role in reducing particle size, increasing specific surface area, and decreasing the depleted area of the reinforcement phase, thereby facilitating significant grain refinement. It is noteworthy that despite maintaining consistent overall reinforcement-phase content, the reduction in the depleted area of the reinforcement phase effectively restricts the growth of coarse grains [40]. The microstructure of titanium composites is significantly influenced by the coefficient of mismatch.…”

Nondestructive measurement of the mechanical properties of graphene nanoplatelets reinforced nickel aluminium bronze composites

“…In recent times, research advances in materials development have favoured the application of powder metallurgy techniques such as spark plasma sintering (SPS) in fabricating NAB systems with finer microstructures and limited grain segregations. Spark plasma sintering is an improved consolidation technique that employed uniaxial load to compact powder materials at a lesser time, lower temperature and minimizes grain growth during consolidation [ 13 ]. Past works have emphasized the advantages of the application of SPS over other conventional materials processing techniques in the fabrication of alloys and metal matrix composites which are quite enormous [ 13 , 14 ].…”

“…Spark plasma sintering is an improved consolidation technique that employed uniaxial load to compact powder materials at a lesser time, lower temperature and minimizes grain growth during consolidation [ 13 ]. Past works have emphasized the advantages of the application of SPS over other conventional materials processing techniques in the fabrication of alloys and metal matrix composites which are quite enormous [ 13 , 14 ].…”