Investigation of the Microstructure and Nanoindentation of Processed Ti6Al4V-5ZrO₂-xSi₃N₄ Ternary Composites Using Powder Metallurgy

Abstract:

Investigating how two different ceramic additives affect the microstructure and nanomechanical characteristics of the Ti6Al4V matrix forms the goal of this work. Under 50 MPa pressure, 10 min dwell time, and 100 °C/min sintering rate at 950 °C, a pulsed electric current sintering process, or PECS, was used. An XRD spectrometer was used to examine the phases, and SEM-EDS was used to examine the bulk morphology of the starting powders and sintered composites. The fabricated Cs1, Cs2, and Cs3 composites attained theoretical densities of 99.74, 98.90, and 96.7%, respectively, above 96.22% of unreinforced Ti-alloy. The SEM analysis showed an even dispersion of the ceramic reinforcements in the matrix of Ti6Al4V, with the characteristics of porous craters in all the samples. Of the three composite samples, Cs1 showed the highest elastic modulus, micro, and nanohardness absolute values of 173 GPa, 796 MPa, and 8942 MPa, respectively, as compared to the unreinforced titanium alloy of 114 GPa, 589 MPa, and 6466 MPa. It was thought that the improved mechanical properties of the sintered composites were due to the production of intermediate phases of Ti₂N and SiO₂ during the sintering process. The materials improvement stands at approximately 30% of the unreinforced Ti-alloy.

• Periodical: Key Engineering Materials (Volume 1026)
• Pages: 49-62
• DOI: https://doi.org/10.4028/p-ax4rS3
• Online since: October 2025
• Authors: Anthony O. Ogunmefun*, Emmanuel Rotimi Sadiku, Linda Moipone Teffo, Williams K. Kupolati
• Keywords: Microstructure, Nanomechanical Properties, Porosity Evaluations, Pulsed Electric Current Sintering, Relative Density, Si₃N₄, Ti6Al4V, ZrO2

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