Characterization and Tribo-mechanical properties investigation of HA/ZrO2/CNT composite

Abstract

The aim of this study was to investigate the tribomechanical properties of hydroxyapatite (HA)/Zirconium oxide (ZrO2) and HA/ZrO2/CNT (carbon nanotubes with different ratios including 1mg, 5mg, and 10mg) composite ceramics. In this paper, HA/ZrO2/CNT nanocomposites powders were synthesized using hydrothermal technique. A bulk and solid tablet was fabricated using cold isostatic (CIP) and hot isostatic (HIP) techniques. The mechanical and tribological properties of HA/ZrO2 and HA/ZrO2/CNT were examined. Using Transmission Electron Microscope(TEM), Scanning Electronic Microscope（SEM）, Energy-dispersive X-ray analysis (EDX) as well as X-ray Diffraction (XRD) to analyze the structure and morphology of the composites. The consolidation process was accomplished by sintering the compounds under argon gas atmosphere at 1150 °C during HIP process. Using Vickers hardness tester, reciprocating wear tester equipment, the effects of ZrO2 and CNT on the tribo-mechanical properties of the HA-nanoparticles-based ceramic composites were investigated. The hardness test results show that HA/ZrO2/CNT1mg exhibited the best surface hardness (356HV) compare to the others. The HA/ZrO2/CNT10mg disc exhibited the highest average COF and HA/ZrO2/CNT5mg exhibited the second highest COF among all the samples. With the enhance in the CNT content in the nanocomposites from 0 to 10mg, the HA/ZrO2/CNT1mg composite appeared to have better wear resistance. The COF of the composites with CNT decreased by almost 30% compared to HA/ZrO2.