Effect of Strain on the Formation of a MAX Phase in Ti–Al–C Materials during Self-Propagating High Temperature Synthesis and Extrusion

Resumo

This paper presents numerical modeling results and experimental data on thermal conditions in Ti–Al–C MAX phase-based materials during self-propagating high-temperature synthesis (SHS) and extrusion. Based on a mathematical model for the thermal conditions of SHS extrusion, which makes it possible to analyze longitudinal and radial temperature profiles in an extruded sample with a model composition (64.2 wt % Ti + 27.1 wt % Al + 8.7 wt % C), we make recommendations as to favorable conditions for MAX phase formation in relation to strain, predict such conditions, and qualitatively compare the theoretical results and experimental data. We examine the effect of the delay time before compaction on the surface defect density of the samples and the effect of strain on the structure and surface quality of the extruded materials. Samples 10 mm in diameter are shown to be free of titanium carbide, whereas samples 5 and 8 mm in diameter contain 6–8 wt % titanium carbide.