Machinable Dy-containing beta-Ca-3(PO4)(2) ceramics

The Dy-containing beta-Ca-3(PO4)(2) (abbreviated as beta-TCP) ceramics obta ined by heating the mixtures of DyPO4 and beta-TCP with DyPO4/beta-TCP (abb reviated as D/T)=0.10-0.25 in molar ratio sintered at 1300 degrees C for 3 h in air were found to be machinable; they can be drilled and out easily us ing conventional inexpensive metallic Fe-Mo-W drills or gravers. The maximu m relative density was 97% at 1300 degrees C, over 98% at 1350-1400 degrees C. The banding strength, Vickers' hardness acid linear thermal expansion c oefficient of the specimens (D/T=0.10-0.15) sintered at 1300 degrees C for 3 h were in the range of 30-50 MPa, 2-3 GPa and 11x10(-6) degrees C-1-12x10 (-6) degrees C-1 (20-900 degrees C), respectively. (C) 2000 Elsevier Scienc e S.A. All rights reserved.