Mechanical Properties of Cr₂AlC Ceramics

Abstract

Dense and predominantly single‐phase samples of Cr2AlC, together with a trace amount of Cr7C3, were fabricated by hot pressing of a mixture of chromium, aluminum, and graphite powders at 1400°C for 1 h. The hardness, Young's modulus, flexural strength, and compressive strength of Cr2AlC samples were 5.2, 288 GPa, 483±29, and 1159±23 MPa, respectively, which are comparable with those of Ti3AlC2 and Nb2AlC. The material exhibits good damage tolerance. For indentation loads up to 50 N, the post‐indentation flexural strengths decrease by approximately 10% and by 31% for a load of 100 N. The flexural strengths of Cr2AlC samples quenched from 300°C to room temperature decrease from 483 to 455 MPa, while the retained strengths decrease quickly to 199 MPa when the quench temperature increases to 500°C. A further increase in quench temperature to 700°, 900°, and 1100°C results in a small reduction of strength.

Tailoring of the thermal expansion of Cr2(Alx,Ge1−x)C phases

“…An indirect support of this conclusion is that the Young's modulus measured for Cr 2 AlC in Ref. [56] is significantly lower than other reports [53,57] on the same material.…”

“…c) The shear modulus of Cr 2 AlC is reported to be 102 GPa [56], 116 GPa [53], and 121 GPa [57]. Even though there is some spread in these experimental data, it is clear that the shear modulus of Cr 2 AlC is significantly higher than that of Cr 2 GeC at ≈ 80 GPa [55].…”

“…3c) b) At ≈ 285 GPa, the Young's modulus of Cr 2 AlC [52,53,54] is significantly higher than that of Cr 2 GeC at 245 GPa [55].…”

Cr2AlC powders prepared by molten salt method

“…Later, study of the mechanical properties of Cr 2 AlC was performed and the results have shown that Cr 2 AlC has the comparable properties to that of Ti 3 SiC 2 [11]. And according to the results in our previous work dealing with the effects of composi- * Corresponding author.…”

“…Secondly, no any sintering assistant is added to the fabrication of bulk Cr 2 AlC sample by Cr 2 AlC powders, which means the sintering is totally a solid reaction process and the densification becomes a little difficult. Table 1 sums up the density and the hardness of MSNA10 sample, in which NCAC10 sample [11] are also listed for comparison. It is found that the density of MSNA10 sample is higher than that of NCAC10 sample.…”