Processing and properties of flame sprayed polyamide 12/n-SiO_2 coatings
Polyamide 12(PA12) and its composite with nanometer-sized silica(PA12/n-SiO2) coatings were prepared by the flame spraying process.The thermal behavior,mechanical and tribological properties of the coatings were investigated with differential scanning calorimeter(DSC),electronic tensile testing machine and wear-test machine of MRH-3.Fourier transform infrared spectroscopy(FTIR) was used to characterize polymer degradation.The FTIR analysis did not reveal the presence of any oxidation or degradation during the processing.The results showed that the addition of nano-SiO2 could increase the crystallinity,improve the mechanical properties of the coatings and reduce friction and wear of pure polyamide 12 effectively.In addition,the nanocomposite coating containing 1.5%(mass) nanometer-sized silica displayed better properties.