Parameters of the Unit Cell of the Ti₃AlC₂ MAX‐Phase with Hydrogen

Abstract

Investigations of the penetration of hydrogen into ternary carbides (the so‐called MAX phases) become topical because it has been found recently that these materials can be protective coatings. Herein, near‐surface layers of two bulk samples of the Ti3AlC2 MAX phase are saturated electrolytically several times by hydrogen. Parameters of the hexagonal unit cell are measured by means of X‐ray diffractometry after each saturation of the same sample. It is found that the increase in the distance between the base planes of the unit cell is ten times larger than the increase of the side of the unit cell in the base plane. The estimated amount of hydrogen that remains in the lattice at room temperature is about 1.6% (at). It is found that the sample can be saturated by hydrogen up to 3% (at), but the lattice relaxes with time. The relaxation time for the distance between base planes is about 60% of that for the side of the lattice in the base plane.

The Electrical Resistivity of Multiphase Systems Based on the Ti3AlC2 Hexagonal Phase at Low Temperatures

“…The X‐ray pattern of the sample made from tablet 1 (i.e., for the pure Ti 3 AlC 2 MAX phase) is shown in another study. [ 19 ] Measurements of concentrations of elements on surfaces of samples were carried out with the use of scanning electron microscopy Tescan Vega 3 LMH with the detector of the characteristic X‐ray radiation Bruker XFlash 5010. Images and X‐ray spectra were obtained at the accelerating voltage of 30 kV without additional conductive coverage.…”