The aim of this study is to investigate the phase stability of the prepared TiCx in Ti-Al-C system after immersion in the mixture of hydrofluoric acid (HF) and H2O2. The powders were immersed in the solution for different period times of 24, 48 and 96 h. The phase change of powders after different immersion times was studied by X-ray diffraction (XRD). The morphology evolution was detected by the field-emission scanning electron (FESEM). Moreover, atomic absorption spectroscopy (AAS) analysis was employed to study the changes in the chemical composition of solutions. The XRD results showed that by increasing the immersion time, gradually, the TiCx decomposed. It was also found that the selection oxidation aluminum occurred and the Al2O3 was the main final product of treatments. The FESEM images also confirmed the XRD results and after immersion of the powders into the solutions the rod-like and sheet-like morphology of the Al2O3 particles were obtained. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.