Atomic-Oxygen-Durable and Antistatic α-Al<i>_x</i>Ti<i>_y</i>O/γ-NiCr Coating on Kapton for Aerospace Applications

Abstract

Polymers used for the exteriors of spacecraft are always exposed to risks such as atomic oxygen (AO) or electrostatic discharge (ESD) degradation. In this work, an Al<i>_x</i>Ti<i>_y</i>O/NiCr coating with excellent mechanical stability, AO durability, and electrostatic dissipative properties was deposited via ion implantation (IIP), filter cathode vacuum arc (FCVA), and high-power impulse magnetron sputtering (HiPIMS) on a flexible Kapton substrate. Scratch and cycle folding tests indicated good adhesion and toughness of the Al<i>_x</i>Ti<i>_y</i>O/NiCr-coated Kapton, which were due to the gradient structure fabricated by the multitechnology combination. AO exposure tests demonstrated an extremely low erosion yield (<i>E</i>_y = 5.15 × 10^-26 cm³ atom^-1) of the Al<i>_x</i>Ti<i>_y</i>O/NiCr-coated Kapton, only 1.72% of that observed for pristine Kapton. Moreover, Rutherford backscattering spectrometry (RBS) and Kelvin probe force microscopy (KPFM) results showed that the Al<i>_x</i>Ti<i>_y</i>O/NiCr-coated Kapton has elevated surface electrostatic dissipative properties and sufficient conductivity. The multitechnology combination offers great flexibility for customizing the gradient structure to realize a comprehensive performance improvement. In addition, such a coating has great prospects for aerospace applications.