Microstructure and mechanical properties of a Cr2Al(Si)C solid solution

A new Cr2Al(Si)C solid solution has been synthesized by hot pressing a mixture of Cr, Al, Si and C powders with a molar ratio of 2:1.1:0.2:1 at 1450 degrees C with 30 MPa for 1 h in Ar atmosphere. The phase composition and microstructure was investigated with X-ray diffraction analysis and scanning electron microscopy. The Cr2Al(Si)C solid solution exhibits a layered structure. The flexural strength, fracture toughness and Vickers hardness of the Cr2Al(Si)C solid solution was determined and compared with the values for synthesized Cr2AlC. Buckling and kinking of the layered structure as well as grain delamination crack deflection were extensively observed around indentations and on the fracture surfaces. These multiple energy-absorbing mechanisms endow the sold solution with damage tolerance and micro-scale plasticity at room temperature. (C) 2010 Elsevier B.V. All rights reserved.