Corrosion performance of Ti3SiC2, Ti3AlC2, Ti2AlC and Cr2AlC MAX phases in simulated primary water conditions.

The response of Ti 3 SiC 2 , Ti 3 AlC 2 , Ti 2 AlC and Cr 2 AlC MAX phases under simulated primary water has been explored for the first time. Samples were tested for 28 days in 300 °C water with the addition of 2 ppm LiOH. The Ti-based MAX phases formed oxides of TiO and TiFeO 3 . X-ray diffraction and scanning electron microscopy showed no evidence of a passive Al or Si-based layer forming during testing. A-layer dissolution was observed to cause delamination of the layered structure. In contrast, Cr 2 AlC showed little change during autoclave testing, suggesting that a thin passivating chromia layer was formed. [ABSTRACT FROM AUTHOR]