Defect behavior and radiation tolerance of MAB phases (MoAlB and Fe2AlB2) with comparison to MAX phases

Abstract

MAB phases are a new class of layered ternary materials that have already shown a number of outstanding properties. Here, we investigate defect evolution and radiation tolerance of two MAB phases, MoAlB and Fe2AlB2, using a combination of experimental characterization and firstprinciples calculations. We find that Fe2AlB2 is more tolerant to radiation-induced amorphization than MoAlB, both at 150 °C and at 300 °C. The results can be explained by the fact that the Mo Frenkel pair is unstable in MoAlB and as a result, irradiated MoAlB is expected to have a significant concentration of MoAl antisites, which are difficult to anneal even at 300 °C. We find that the tolerance to radiation-induced amorphization of MAB phases is lower than in MAX phases, but it is comparable to that of SiC. However, MAB phases do not show radiation-induced cracking which is observed in MAX phases under the same irradiation conditions. This study suggests that MAB phases might be a promising class of materials for applications that involve radiation.

Helium effects and bubbles formation in irradiated Ti3SiC2

“…For the 750 °C irradiated sample, the changes in the hardness and Young's modulus are much smaller than those for the RT irradiated sample, which confirms that the Ti 3 SiC 2 has better tolerance for irradiation induced mechanical properties change at 750 °C than that at RT, although changes of ~8-10% in mechanical properties observed at 750 °C are not insignificant. Modulus/GPa and at 750°C from [11][12][13][14][15][16][17][18][19][20] are shown in Figs. 6a and 6b, respectively.…”

“…Specifically, under ion irradiation, Ti 3 SiC 2 was found to remain crystalline even at a very high dose of 116.9 displacements per atom (dpa) [11]. Furthermore, experiments have shown that at temperatures above 400 °C, Ti 3 SiC 2 has a better resistance to radiation-induced cracking as compared with other MAX phase materials, such as Ti 3 AlC 2 and Ti 2 AlC [9,12,13].…”

“…Fig 6. TEM image of the Ti 3 SiC 2 samples, observed from[11][12][13][14][15][16][17][18][19][20], irradiated at (a) RT, the white spots are He bubbles, the black region is the damage peak region which has a high density ofblack spots defects and (b) 750℃. (c) HRTEM of the Ti 3 SiC 2 samples irradiated at 750 ℃ showing a He bubble located in the bulk and aligned parallel to basal plane.…”

Synthesis and properties of MoAlB composites reinforced with SiC particles

“…MoAlB, as the most studied MAB phase, has been widely investigated from theoretical simulations [3][4][5] to experimental studies, and exhibits attractive mechanical properties, high temperature properties, radiation tolerance, and ablation resistance [6][7][8][9][10][11][12]. So far, MoAlB as the only one in the MAB phase family has been demonstrated with better oxidation resistance than other Al-containing MAB phases (such as Fe 2 AlB 2 and Cr 2 AlB 2 ) at temperatures below 1300 ℃ due to J Adv Ceram 2022, 11(2): 0-0 www.springer.com/journal/40145 the formation of a dense and continuous α-Al 2 O 3 layer [13][14][15][16].…”

Electronic structure, bonding characteristics, and mechanical behaviors of a new family of Si-containing damage-tolerant MAB phases M5SiB2 (M = IVB—VIB transition metals)

“…Inspired by the unique properties of the MAX phases, a family of nano laminated ternary borides, named MAB phases (where M is a transition metal, A is a IIIA or IVA group element, and B is boron) were proposed by Ade and Hillebrecht [4] in 2015. MAB phases are anticipated to exhibit similar properties to the MAX phases, such as good electrical conductivity, damage tolerance [5,6], resistance to thermal shock [7] and oxidation [8] at high temperatures, as well as superior high-temperature strength [7] and self-healing capability of cracks [9].…”