# Reactive Synthesis for Porous (Mo2/3Y1/3)2AlC Ceramics through Mo, Y, Al and Graphite Powders

## TL;DR

This paper describes a method to create porous (Mo2/3Y1/3)2AlC ceramics using a reactive sintering process and examines how temperature affects the material's structure and properties.

## Contribution

The study introduces a novel reactive synthesis method for porous (Mo2/3Y1/3)2AlC ceramics and elucidates the phase transition and pore formation mechanisms.

## Key findings

- At 650–850 °C, aluminum-containing intermetallics and carbides form from transition metals and aluminum.
- At 850–1250 °C, transition metal carbides form through reactions with graphite.
- The final (Mo2/3Y1/3)2AlC phase forms at 1250–1450 °C through interactions of intermetallics and carbides.

## Abstract

Through an activation reaction sintering method, porous (Mo2/3Y1/3)2AlC ceramics were prepared by Mo, Y, Al, and graphite powders as raw materials. The phase composition, microstructure, element distribution, and pore structure characteristics were comprehensively studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), Archimedes method, and bubble point method. A detailed investigation was conducted on the influence of sintering temperature on the phase composition. Possible routes of phase transition and pore formation mechanisms during the sintering process were provided. The experimental results reveal that at 650–850 °C, transition metals react with aluminum, forming aluminum-containing intermetallics and a small amount of carbides. At 850–1250 °C, transition metals collaborate with graphite, producing transition metal carbides. Then, at 1250–1450 °C, these aluminum intermetallics interact with transition metal carbides and remaining unreacted Y, Al, and C, yielding the final product (Mo2/3Y1/3) 2AlC. Simultaneously, the pore structure alters correspondingly with the solid-phase reaction at different reaction temperatures.