Microstructure-oxidation resistance relationship in Ti3AlC2 MAX phase

JOURNAL OF ALLOYS AND COMPOUNDS

卷:826

Article

Drouelle, E.^1,2  Gauthier-Brunet, V¹  Cormier, J.¹  Villechaise, P.¹  Sallot, P.²  Naimi, E.³  Bernard, F.³  Dubois, S.¹ 

[1] Univ Poitiers, Inst PPRIME, CNRS, ENSMA,UPR 3346, Blvd M&P Curie,TSA 41123, F-86073 Poitiers 9, France

[2] Safran Tech, 1 Rue Genevieve Aube,CS 80112, F-78772 Magny Les Hameaux, France

[3] Univ Bourgogne Franche Comte, Lab Interdisciplinaire Carnot Bourgogne, UMR 6303, CNRS, 9 Av Alain Savary,BP 47870, F-21078 Dijon, France

关键词: MAX phase;    Powder metallurgy;    SPS;    Microstructure;    Grain size;    Oxidation;   

DOI  :  10.1016/j.jallcom.2020.154062

来源: Elsevier

【 摘 要 】

Spark Plasma Sintering and Hot Isostatic Pressing were used to synthesize coarse-grained and fine-grained Ti3AlC2 specimens. Moreover, Spark Plasma Sintering processing parameters were modified in order to vary the TiC, Al2O3 and TixAly impurity and the porosity contents in the fine-grained samples. The influence of the Ti3AlC2 microstructure on the oxidation resistance was assesed. It is demonstrated that the grain size can drastically modify the oxidation resistance. The higher density of grain boundaries, in fine-grained specimens, increases the number of Al diffusion paths and leads to the formation of a protective alumina scale. In coarse-grained sample, Al diffusion is the rate limiting step of the alpha-Al2O3 formation and TiO2 is formed simultaneously to alumina. TiC impurities and porosity are demonstrated to be detrimental to the oxidation resistance in the 800 degrees C-1000 degrees C temperature range by favouring TiO2 formation. Finally, it is also shown that, for fine-grained specimens, the oxide scale grows very slowly for oxidation times in the range 20-40 days. (C) 2020 Elsevier B.V. All rights reserved.

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