1989 Volume 97 Issue 1129 Pages 965-967
Tricalcium phosphate (TCP) was HIP'ed in a glass capsule at 800°-1100°C and 100MPa for 30min. Soda-lime glass was more suitable than Pyrex glass as a capsule material because of less thermal expansion mismatch from HIP-sintered TCP. Alumina powder was suitable as a barrier layer between glass capsule and sample, but boron nitride powder seemed to be reacted with the sample. The dense and transparent TCP ceramics were obtained by HIPing above 1000°C. In the comparison with pressureless sintering, the HIP treatment lowered the densification temperature as much as 200°C and also improved mechanical properties, 120MPa for bending strength and 0.8MPa·m1/2 for fracture toughness.