Self-healing M_n+1AX_n-phase ceramics

Damage management and the development of new materials come together in selfhealing Mn+1AXn phase ceramics. These ternary layered carbides and nitrides exhibit a multitude of properties, such as high temperature strength, fracture toughness, thermal and electrical conductivity and machinability, which have been discovered over the past 20 years. In addition, intrinsic crack-gap filling and strength recovery by high temperature oxidation have been demonstrated for Ti2AlC, Cr2AlC and Ti3AlC2. The selective oxidation of the A-element, Aluminium in all known cases, leads to almost full crack gap closure by Al2O3 filling. The dense, strong and well adhering oxide is formed at temperatures above 1000 ±C in atmospheric air and can restore the integrity of a sample even formultiple successive crack-healing cycles.(OLD) MSE-