Preparation and Characterization of Core-Shell Composite Based on Fe Powder and Phenol-Formaldehyde Resin Modified with Nanometer-Sized Sio_2

摘要

Fabrication of Fe(core)/PFR-SiO_2(shell) composite based on Fe powder particles and phenol-formaldehyde resin (PFR) modified with nanometer-sized SiO_2 is investigated in detail. The chemical synthesis of PFR, its modification with nano-SiO_2 and subsequent coating enables a rather precise control of electrically insulating PFR-SiO_2 layer on the surface of Fe powder particles. The thermogravimetric analysis of both PFR-SiO_2 coating as well as Fe/PFR-SiO_2 composite was performed. A correlation between mechanical hardness and flexural strength of Fe/PFR-SiO_2 composite was studied in dependence on the amount of nano-SiO_2 in the coating. SEM analysis of prepared Fe/PFR-SiO_2 composite show microstructure without defects, pores and cracks. The morphology of coated Fe powder particles implies a very uniform coating without any visible exfoliation.