Fe-Based Micro- and Nanocomposite Coatings Produced by Amorphous Alloy Crystallization Based on Electrospark Deposition

Abstract

The aim of this paper is to explore the possibility of a novel surface technique for Fe-based amorphous and micro-nano composite coatings. A kind of iron based amorphous and micro/nano-crystalline alloy powder which contains Fe, Ni, Cr, W, Mo, B, Si, C etc. was first prepared by mechanical alloying method. Iron based amorphous alloy coatings were then deposited on nodular cast iron substrate by electro-spark deposition using electrode materials with the ball-milling iron based alloy and SiC mixed powders. Annealing crystallization treatment of the Fe-based amorphous alloy coatings was conducted at last. The microstructure and surface morphology of the coating were analyzed by optical microscopy (OM) and scanning electron microscopy (SEM), the amorphous and crystal configuration were confirmed with an X-ray diffractometer (XRD), the microhardness was measured with a micro-sclerometer. The experimental results show that the Fe-based composite coatings are composed of Fe-based amorphous alloy matrix and dispersion strengthened micro- and nanocrystalline particles. The coatings of about 60 m in thickness are uniform, dense and metallurgically bonded to the substrate with high microhardness of about 880 (HV100, 15 S), implying a much improved wear resistance on surface of cast iron.