SINTERING AND PROPERTIES OF MONAZITE-TYPE CEPO4

Monazite-type CePO4 powder (average grain size 0.3-mu-m) was dry-pressed to disks or bars. The green compacts began to sinter above 950-degrees-C. Relative density greater-than-or-equal-to 99% and apparent porosity < 1% were achieved when the specimens were sintered at 1500-degrees-C for 1 h in air. The linear thermal expansion coefficient and thermal conductivity of the CePO4 ceramics were 9 x 10(-6)/degrees-C to 11 x 10(-6)/degrees-C (200-degrees to 1300-degrees-C) and 1.81 W/(m.K) (500-degrees-C), respectively. Bending strength of the ceramics (average grain size 4-mu-m) was 174 +/- 28 MPa (room temperature). The CePO4 ceramics were cracked or decomposed by acidic or alkaline aqueous solutions at high temperatures.