Preparation of SiC<sub>w</sub>-ZTA Composites by Two-Step Sintering or Spark Plasma Sintering

Alumina materials are widely used in the industry as cutting tool inserts. In order to improve mechanical properties of the Al 2 O 3 matrix, different reinforcing phases are introduced. In the presented work, reinforcements in the form of ZrO 2 particles and SiC nanofibres have been used. ZTA-SiC composites were obtained from 0.5%MgO-20%(3Y 2 O 3 )ZrO 2 -79.5%Al 2 O 3 powder and 15% of SiC whiskers. Tested materials have been prepared by means of the two-step sintering (TSS) and spark plasma sintering (SPS). TSS method permits to obtain dense materials with fine-grained microstructure. TSS has been carried out for two different sintering times: 1 hour 20 minutes and 8 hours. Due to the reactivity of the components, the SPS method has been used to shorten sintering times. SPS has been performed at two different temperatures: 1500 °C and 1550 °C.