Synthesis and characterization of cBN-Al2O3-Al cutting tool material by dual power spark plasma sintering.

A cBN-Al 2 O 3 -Al cutting tool material was prepared by a dual power spark plasma sintering method, and the effects of sintering temperature, holding time and Al 2 O 3 content on the microstructure and mechanical properties of cBN-Al 2 O 3 -Al cutting tool material were studied. The results showed that the dual power sintering method strengthened the spark plasma generated between the particles, increased the uniform discharge effect of the metal Al in the sintered body, generated a local high temperature and reacted with the activated cBN to produce AlN, and inhibited the phase change of cBN. When the sintering temperature was 1500 °C, the holding time was 5 min, and the pressure was 50 MPa, the overall mechanical properties of cBN-Al 2 O 3 -Al cutting tool material with 50 wt% Al 2 O 3 content were the most optimal, with a hardness of 24.45 GPa, a fracture toughness of 5.92 MPa·m1/2, and a flexural strength of 423 MPa. • cBN-Al 2 O 3 -Al cutting tool material was prepared by pulsed direct current and 200 kHz high-frequency dual power SPS sintering. • The conversion from cBN to hBN was inhibited by dual power supply sintering. • Find the best sintering temperature, holding time, Al 2 O 3 content, respectively 1500 °C, 5 min, 50 wt%. • The maximum hardness and flexural strength are 24.45 GPa and 423 MPa respectively. [ABSTRACT FROM AUTHOR]