Capillary Phenomena during Interaction of Copper Melt with Dense and Porous MAX Phases with General Formula (Cr,Mn)₂AlC

In this study, we experimentally investigated the interaction of a pure copper melt with dense MAX phase (Cr,Mn)₂AlC obtained as a result of sintering by the spark plasma method and with a porous phase compacted by room temperature pressing. The porous phase (porosity 20%) absorbs a molten copper at temperatures above 1200°C. The absorption kinetics is measured using a high speed (HS) thermo-visioning camera and an HS video camera. The experiments are carried out under a vacuum pressure of 10^–3 Pa. Scanning electron microscopy studies, microanalyses by the method of X-ray spectroscopy, and X-ray diffraction studies have shown that chemical reactions of the MAX phase with a copper melt lead to the formation of a solution of aluminum and chromium in copper and the decomposition of the MAX phase to stable and/or metastable chromium carbides. The dense sintered sample reacts with the melt though the contact (wetting) angles are more than 100°. The difference between porous and dense samples is in the reaction kinetics. The obtained results are compared with the earlier conducted experiments on wetting of the Cr₂AlC MAX phase by a Cu melt (with 0.8 at % Cr). The conditions in the earlier described experiments and the results of determining changes in the chemical composition and the phase composition during capillary experiments indicate that a composite material with a submicrometer structure of chromium carbide impregnated with aluminum bronze can be obtained.