Synthesis and mechanical properties of nano laminating Cr2AlC using CrCx/Al powder mixtures

Abstract

Cr2AlC, one of the ternary carbide families, was synthesized by a reactive hot pressing of CrCx (x=0.5) and At powder mixture used as starting materials at the temperature range of 1200 degrees C-1400 degrees C under 25 MPa in Ar atmosphere. Fully dense Cr2AlC with high purity was synthesized by hot pressing CrCx and Al powder mixture at the temperature as low as 1200 degrees C. After synthesizing the bulk Cr2AlC, it was found that it has a typical layered structure as found in other ternary carbides such as Ti3AlC2 and Ti3SiC2. The average grain size of synthesized bulk Cr2AlC was varied in the range of 10-100 mu m depending on hot pressing temperatures. The Vickers hardness of bulk Cr2AlC was less than 4 GPa under the loading of 10N and this decreased with increasing indentation load. The maximum flexural strength of synthesized bulk Cr2AlC exceeded 600 MPa. Also, it was found that synthesized Cr2AlC was readily machinable by a conventional WC tool bit due to its low hardness as well as damage tolerance properties upon fracture.