Mechanical properties of SPS-processed Cr2AlC MAX phase with different impurity contents

The formation of Cr7C3 during the sintering of Cr2AlC MAX phase is an inevitable issue that can affect the properties of samples. In this study, with the alteration of milling time of Cr-Al-C powders, Cr2AlC samples with different purities were fabricated by spark plasma sintering (SPS) method, and the role of purity of samples on the mechanical properties of samples was studied. According to the results, the content of Cr2AlC phase increased by the milling time increment. The flexural strength, compressive strength, and Vickers hardness of the sample with 65 wt% Cr2AlC were 613 +/- 12 MPa, 1268 +/- 25 MPa, and 5.9 +/- 0.1 GPa, and for the sample with 97 wt% Cr2AlC were reduced to 475 +/- 10 MPa, 953 +/- 18 MPa, and 5.4 +/- 0.1 GPa, respectively. This behavior can be attributed to the strengthening effect of Cr7C3. The fractographic studies showed that the specimen with the highest purity contains delamination and kinking mechanisms which depicts that this sample is ductile and damage tolerant.

Automated summary

By altering the milling time of Cr-Al-C powders, Cr2AlC samples with different purities were fabricated using the SPS method, and the impact of purity on the mechanical properties of the samples was studied. It was found that the content of Cr2AlC phase increased with increasing milling time. The flexural strength, compressive strength, and Vickers hardness decreased as the purity of Cr2AlC decreased, which can be attributed to the strengthening effect of Cr7C3. Fractographic studies revealed that the specimen with the highest purity exhibited ductile and damage tolerant behavior.