95 / 2021-07-09 16:24:45

Effect of low dose self-ion irradiation on structure and mechanical properties of nanocrystalline TiAlN coating

Hardness,Nanocrystalline,Self-ion irradiation,TiAlN coating

Ceramic coating can be used as protective coating for fuel cladding. In addition to having excellent corrosion resistance and high temperature oxidation resistance, it should also have enough radiation resistance to maintain stable phase structure under irradiation conditions. TiAlN ceramic coatings were deposited on 304L austenitic stainless steels and silicon wafers by magnetic filtered cathode vacuum arc (FCVA) method under different N₂ flow rates. The relationship between the structure change and mechanical properties of the coatings under irradiation was studied. The phase composition and structure of the coating were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanical properties of TiAlN coating were characterized by Rockwell indentation, nano indentation and scratch tester. The results show that the stability of Ti under irradiation is higher than that of N and Al. The grain size of TiAlN coating is refined under Al⁺ irradiation, and the hardening behavior caused by high energy low dose ion irradiation can be observed. When the N₂ flow rate is 40 sccm, the grain size decreases from 22.3 nm to 18.76 nm, the nano-hardness increases from 44.84 GPa to 46.56 GPa, and the Vickers hardness increases from 2972.91 Hv_0.5 to 3344.23 Hv_0.5. No blistering or spalling occurred in all irradiated coatings.