Synthesis and mechanical properties of high-purity Cr2AlC ceramic

High-purity and dense Cr2AlC has been successfully fabricated by hot-pressing, using Cr, Al and graphite as raw materials. Delamination, kink bands, monolamellar kink, transgranular crack and transgranular fracture of bulk Cr2AlC are found during the room-temperature test. The density, Vickers hardness, flexural strength, Youngʹs modulus, compressive strength and fracture toughness of the Cr2AlC are 5.17 g/cm3, 4.9 GPa, 469 ± 27 MPa, 282 GPa, 949 ± 22 MPa and 6.22 ± 0.26 MPa m1/2, respectively. The strength of Cr2AlC could be greatly improved by second phase of Cr7C3. And the slipping of basal planes and slip system cold be hindered by Cr7C3, thus resulting in a lower toughness.