On the formation, structural and mechanical characterization of nanolayered Zr2AlC MAX phase via aluminum molten infiltration

Abstract

This research study aimed to investigate the synthesis, microstructural and mechanical characterization of novel Zr-based layered ternary carbide, Zr2AlC MAX phase, by using liquid aluminum infiltration from ZrC preform. For this purpose, a stoichiometric mixture of high-purity powders of ZrH2 and C with a molar-ratio of 2:1 was subjected to intense milling. Infiltration of molten Al to mixed-powders was performed in different conditions. The morphological observation and mechanical behavior manufactured samples were identified by X-ray diffractometry, scanning electron microscopy and microhardness measurements. The experimental findings confirmed that after an optimum infiltrating of 5 h, the Zr2AlC MAX phase with Vickers hardness of 4.5 GPa and fracture toughness of 23 MPa.m0.5 can be achieved. Conversion of ZrC preform and liquid Al during infiltration occurred directly in a single-stage manner without formation of impurity phases. The investigation results revealed that this approach is innovative and can constitute an effective strategy for manufacturing single-phase Zr2AlC with nanolaminated structure and suitable morphology.