Microstructural Analysis and Corrosion Behavior of a Titanium Cenosphere Composite Foam Fabricated by Powder Metallurgy Route

Abstract

AbstractThis study examines the influence of cenosphere particle size and sintering parameters on the microstructure and electrochemical behavior of Ti‐cenosphere composite foam fabricated by powder metallurgy route. Cenosphere has been added as a space holder material to develop Ti composite foam because of its abundant availability and low cost. Ti (particle size between 250 μm and 350 μm) and cenosphere (with a varying particle size of <150 μm, 150 μm–200 μm and >200 μm) in the ratio of 75 : 25 (wt %) were compacted using 100 MPa of applied pressure and sintering temperatures of 1000 and 1200 °C with sintering time ranging from 2 to 6 h at a heating rate of 25 °C/min. A defect‐free microstructure with the uniform dispersion of cenosphere particles in the Ti matrix was observed with the cenosphere particles in the size range of 150–212 μm at a sintering temperature of 1000 °C for 4 h. The porosity content in the syntactic foam varied from 34 to 50 % and decreased with increasing sintering time and temperature. Based on a detailed study of corrosion behavior in Hank's solution, the composite foam with cenosphere particles in the size range of 150–212 μm and sintered at 1000 °C for 4 h showed the highest corrosion resistance.