Performances of AlN coatings as hydrogen isotopes permeation barriers

• The D-PRF of AlN-HIPB was studied.
• The morphologies of AlN-HIPB remained compact after deuterium permeation tests.
• The diffraction peaks maintained stable.
• The nano-hardness increased after the deuterium permeation tests.

Hydrogen isotope permeation barriers (HIPB) have great potential applications in the fields of hydrogen energy and thermonuclear fusion. In this study, the AlN-HIPB were prepared on 316 L stainless steel by RF magnetron sputtering. The properties of AlN-HIPB were studied, including the deuterium permeation reduced factor (D-PRF), structures and nano-hardness. The D-PRF of 0.4 μm AlN-HIPB could reach 36 at 600 °C, and gradually rise with decreasing permeation temperature. The D-PRF reached 53 at 400 °C and 144 at 250 °C, respectively. The coatings remained dense and the grains were spherical after the deuterium permeation test. The AlN (1 0 0) diffraction peaks appeared and maintained stable during the deuterium permeation process. The nano-hardness of the coatings increased from 5.96 GPa to 7.41 GPa and the elasticity modulus also increased from 156.6 GPa to 210.6 GPa after the deuterium permeation.