Mechanical and microstructural properties of titanium/hydroxyapatite functionally graded material fabricated by spark plasma sintering

ABSTRACT

In this article, different functionally graded material specimens were made from titanium powder and hydroxyapatite (HA) submicron particles. The spark plasma sintering method was applied to fabricate the specimens. Two kinds of starting powder mixture were used: mixed powder and ball-milled powder. Percentage of HA was changed from 0 vol.-% to 40 vol.-% in the different number of layers (2, 3 and 5-layer). The effects of the number of the layers and ball-mill process were investigated on microstructure, microhardness, compressive strength and fracture surface. The results show that the grain size has been enhanced by increasing the amount of HA in the layers. In addition, the Vickers microhardness has been first increased by enhancing the percentage of HA, while it has been decreased in the layers with a higher amount of it. Furthermore, the highest compressive strength could be achieved in the five-layer samples. Moreover, specimens with ball-milled powder have higher microhardness and less compressive strength.

KEYWORDS:

• FGM
• titanium
• hydroxyapatite
• composite
• SPS
• powder metallurgy
• mechanical properties
• microstructure

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

N. Omidi received her MSc degree in Mechanical Engineering from Iran University of Science and Technology.

A. H. Jabbari is currently a PhD candidate at School of Mechanical Engineering, Iran University of Science and Technology.

M. Sedighi is a Professor at School of Mechanical Engineering, Iran University of Science and Technology.