Depending on the assumption that aerosol concentration index decreases with the altitude increasing, the aerosol scale height indicates boundary character thickness.

T73 and RRA treatment improve the grain boundary character, which is help to inhibit hydrogen embrittlement and decrease anodic dissolution rate, then to improve the SCCR of the alloy.

Architecturally, it creates a permeable skin that not only dissolves the boundary between inside and outside but also defines the visual character of the house.