Applied Surface Science, Vol.343, 41-48, 2015
High-temperature crack-healing behaviour and strength recovery of (MoNb)Si-2
(MoNb)Si-2 materials were prepared using combustion synthesis and the vacuum hot-pressing technology. Cracks were introduced on the surface of polished materials using the Vickers indentation method. The crack-healing behaviour of (MoNb)Si-2 materials were investigated with high-temperature oxidation in air. The results show that after annealing at 900 degrees C, 1200 degrees C and 1500 degrees C for 1 h, the crack-healing behaviour was observed in each case. The bending strength obviously decreased when the cracks were introduced, and the materials significantly recovered after the heat treatment. The crack-healed samples exhibited higher bending strengths than the original level after the 1200 degrees C treatment, e.g. 479 MPa versus 195 MPa of pure MoSi2. MoSi2 micro alloyed with niobium shows a high bending strength at room temperature and excellent crack-healing properties at high temperatures. (C) 2015 Elsevier B.V. All rights reserved.