Effect of a novel sintering process on mechanical properties of hydroxyapatite ceramics

• Published in: Journal of alloys and compounds Vol. 471; no. 1; pp. 180 - 184
• Main Authors: Mazaheri, Mehdi, Haghighatzadeh, M., Zahedi, A.M., Sadrnezhaad, S.K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 05-03-2009; Elsevier
• Subjects: Acoustical properties of solids; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fracture toughness; Grain size; Hydroxyapatite; Materials science; Materials synthesis; materials processing; Mechanical and acoustical properties of condensed matter; Nanopowders; Nanoscale materials and structures: fabrication and characterization; Physics; Two-step sintering; Grain size; Hydroxyapatite; Two-step sintering; Fracture toughness; Scanning electron microscopy; Transmission electron microscopy; Grain growth; Sintering; Phase separation; Mechanical properties; Nanopowder; Phase analysis
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2008.03.066

Two-step sintering (TSS) has been applied, in the present work, to suppress the accelerated grain growth of hydroxyapatite (HA) nanopowder compacts in the last sintering stage. The average grain size of near full dense (>98%) specimens made via conventional sintering (CS) was around 1.7
μm. By using novel two-step sintering, however, the final grain size (∼190
nm) dropped 9 times less than that for the specimens produced by the CS method. Regarding the reduction of the grain size from 1.7
μm (CS method) to 190
nm (TSS method), the fracture toughness of samples increased 95% from 0.98
±
0.12 to 1.92
±
0.20
MPa
m
1/2. Due to the lower second step sintering temperature, the phase analysis shows no HA phase decomposition in TSS method.