Mechanical properties of Fe-Si-B amorphous wires produced by in-rotating-water spinning method

Abstract

Amorphous wires with high strength and good ductility have been produced in Fe-Si-B alloy system by the modified melt-spinning technique in which a melt stream is ejected into a rotating water layer. These wires have a circular cross section and smooth peripheral surface. The diameter is in the range of about 0.07 to 0.27 mm. Their Vickers hardness (Hv) and tensile strength (σf) increase with silicon and boron content and reach 1100 DPN and 3920 MPa, respectively, for Fe70Si10B20, exceeding the values of heavily cold-drawn steel wires. Fracture elongation(e f ), including elastic elongation, is about 2.1 to 2.8 pct. An appropriate cold drawing results in the increase of σf and ef by about eight and 65 pct, respectively. This increase is interpreted to result from an interaction among crossing deformation bands introduced by cold drawing. The undrawn and drawn amorphous wires are so ductile that no cracks are observed, even after closely contacted bending. Further, it is demonstrated that the σf of the Fe75Si10Bl5 amorphous wire increases by the replacement of iron with a small amount of tantalum, niobium, tungsten, molybdenum, or chromium without detriment to the formation tendency of an amorphous wire. Such iron-based amorphous wires are attractive as fine gauge, high strength materials because of their uniform shape and superior mechanical qualities.