Laser sintering of Bi4Ti3O12 ferroelectric ceramics

Bi4Ti3O12 (BIT) ceramics were synthesized by solid-state reaction and sintered by CO2 laser heating. In the sintering process, the laser beam with a diameter of 6 +/- 1 mm was fixed on the center of the sample, which was pre-heated at 350 degreesC. The laser power was raised at a linear rate, according to an irradiation program. The microstructure of laser-sintered ceramics was compared to a reference, which was sintered in electrical furnace. Samples sintered by the conventional process presented grain size of 14 +/- 3 mum, measured along the larger dimension, and relative density of 94 +/- 2%, whereas BIT ceramics sintered under P-max = 1.06 W/mm(2) for 5 min had grain sizes of 7 +/- 4 mum and relative density of 97 +/- 1%. (C) 2002 Elsevier Science B.V. All rights reserved.