Metallization and APPJ treatment of bismaleimide

Abstract

Bismaleimide (BMI) resins are a new breed of thermosetting resins used mainly for high-temperature applications and have major usage in aerospace. Fourier transform infrared (FTIR) studies have shown signatures of imide, C–N–C stretching, maleimide, and N–H stretching. These BMI polymer coatings were deposited on aluminum (Al) and mild steel substrates by sprinkling powers followed by baking. Thermogravimetric analysis and differential scanning calorimetric studies showed the degradation temperature of these polymers around 370°C. Al coatings were deposited on BMI that is previously deposited on Al and mild steel to make a metal–BMI–metal trilayer. These trilayers can solve the problem charging of the aircraft bodies at high altitudes. Atomic force microscopy was done to determine the morphology of the surface. Roughness and thickness measurements of the BMI coatings were carried out by a surface profilometer. Vickers microhardness tests showed an increase in the hardness of the metal–BMI–metal trilayer. FTIR spectrum showed signatures of imides, C–N–C stretching, maleimide, and N–H stretching in BMI. Peak broadening indicates the release of the stress during thermal treatment of the coating. The coating is subject to variable Atmospheric Pressure Plasma Jet (APPJ) conditions, which improves the properties at high temperature. X-ray diffraction studies showed a hint of crystallinity on APPJ treatment.