Preparation of transparent mgalo ceramics by pulsed elec-tric current sintering using two-step heating method

Abstract

Transparent MgAbO4 ceramics were fabricated by pulsed electric current sintering (PECS) employing a two-step sintering mode. First, nanoscale MgAbO4 powders were produced by solution combustion synthesis from hydrated nitrate compounds and urea. Subsequently, the synthesized powders were sintered by PECS with a heating rate of 100°C/min under an applied pressure of 100 MPa. The sintering process was conducted according to a two-step heating profile. At the first step, the temperature increased to 1050, 1100, and 1150°C, followed by a dwell time of 60 min. The second-step sintering was carried out at 1300, 1350, and 1400°C for 20 min. The transparent ceramics sintered at 1050°C/60 min - 1400°C/20 min exhibited transmittance over 80% in infrared range. In addition, transparent samples presented a Vickers hardness up to 30 GPa for sintering mode of 1150°C/60 min - 1400°C/20 min.