Effect of heat treatment on the surface and mechanical properties of CH films

The glow discharge polymer (GDP) films with the thickness of about 7 m were deposited. Under the protection of argon, the GDP films were heated to 300 ℃ for 6 h, 10 h, 24 h. The influence of holding time on the structure of GDP films was characterized by FT-IR. The surface roughness of GDP films after different holding time was investigated by white light interferometer. The hardness and modulus of GDP films were measured by nanoindentation. It is found that while the holding time increases, the relative content of CH3 decreases, the cross-linking degree of carbon network increases, and the surface roughness of GDP films reduces. The hardness and modulus decreases firstly and then increases with the increasing holding time.