The preparation of ductile high strength Fe-base filaments using the methods of glass-coated melt spinning

Abstract

High toughness glass-coated metallic fibres show great promise for use in composite materials as reinforcement for brittle matrixes such as fine ceramics. This paper describes the glass-coated melt spinning of austenitic steel and Fe-B base alloys in order to prepare a ductile high strength filament. The toughness was estimated from the area of the stress-strain curves of the filament obtained. Continuous high toughness steel filament, which had a maximum toughness of 6600 MPa% with a tensile strength of 3050 MPa and an elongation of 3.1% was obtained from the molten state at 1600 K for a winding speed of 7.95 m sec−1. The filament was 3×10−6m diameter and polycrystalline with a grain size of 1000×10−10m. The crystal structure of the filament was a single b c c phase and the phase transformed into a stable f c c structure by heat treatment at 1073 K for 600sec. Ductile filaments of Fe78-xCo5Ni5Cu2B10Mx (Mx∶Cr5–20, Cr5Si3, Cr5Co5, Cr5Ni5, Cr10Mo0.5, Cr10Nb0.5) alloys were also successfully produced. The Fe67.5Co5Cr10Ni5Cu2B10Mo0.5 filament had the highest toughness of 13 900 MPa% with tensile strength of 3760 MPa and an elongation of 4.8%. The filament had a single b c c phase.