Annealing effects on the structure and hardness of helium‐irradiated Cr₂AlC thin films

Abstract

Cr 2 AlC MAX phase thin films prepared by radio-frequency magnetron sputtering were irradiated at room temperature by 100 keV helium ions to a fluence of 1 × 10 17 ions cm −2. The effects of thermal annealing on the structural and mechanical properties of the helium-irradiated Cr 2 AlC films as well as the helium release were investigated by grazing-incidence X-ray diffraction (GIXRD), Raman spectroscopy, and scanning electron microscope (SEM) in combination with nano-indentation and elastic recoil detection (ERD) analysis. The irradiation-induced structural damage in the Cr 2 AlC is significantly recovered by thermal annealing at temperatures around 600℃, attributed to high defect diffusivity. After annealing to 750℃, the hardness of irradiated films recovered almost completely, which is ascribes to both defect recombination and reformation of damaged chemical bonds. Substantial helium release occurring at this annealing temperature is closely related to the damage recovery due to helium irradiation.

Microcrystallization Effects Induced by Laser Annealing in Cr-Al-C Ion-Beam-Sputtered Films

“…Apart from these modes, a very intense, sharp peak appears at about 548 cm −1 . In agreement with previous reports [ 21 ], this quite intense and sharp peak has been assigned to the occurrence of chromium oxides, notably Cr 2 O 3 . All the values recorded for the Raman peaks in the spectra are listed in Table 1 .…”

“…In its bulk form, or subjected to sintering procedures, this system was investigated for other industrial domains [ 17 ]. Some authors studied the effect of changing the synthesis parameters onto the films’ tribology and oxidation behavior [ 18 , 19 , 20 ], while others considered the influence of ion beam annealing onto films of Cr-Al-C [ 21 ].…”

Deviating from the pure MAX phase concept: Radiation-tolerant nanostructured dual-phase Cr 2 AlC

“…Radiation studies on Cr 2 AlC MAX phase are limited to date and have been mostly investigated at room and moderate temperatures (30)(31)(32)(33)(34)(35). Irradiation of Cr 2 AlC MAX phase processed by spark plasma sintering with 7-MeV Xe 26+ and 500-keV He 2+ at 300 K have shown retained crystallinity in doses up to 1 dpa, and notable alterations to their initial mechanical properties were observed (32).…”

Study of Radiation Resistance to Helium Swelling of Li2ZrO3/LiO and Li2ZrO3 Ceramics

“…The problem of helium accumulation in the structure of the near-surface layer and subsequent destruction processes has become quite acute in recent years among studies due to the receipt of a large amount of new experimental data on the mechanisms of gaseous swelling of ceramics [11][12][13][14][15]. According to traditional models of gas swelling for metals, helium accumulation occurs near grain boundaries, followed by deformation of the crystal structure, and leads to the formation of blisters containing helium and exerting bursting pressure on the filled cavity.…”