Mechanical properties of rapidly solidified Fe–Al–B ternary alloys

Abstract

In this work, the influence of Al and B concentration on the constituent phases and the mechanical properties of Fe 100− x− y Al x B y (0 < x ≤ 35, 0 < y ≤ 25, and x + y ≤ 50) ternary alloys produced by copper mould casting was investigated. In this composition range, the rapidly solidified alloys contain two crystalline phases: α-Fe(Al) solid solution and Fe 2B compound. Contour maps of compressive strength ( σ c) and fracture strain ( ɛ f) are plotted according to the quasi-static compression test results of the as-cast Fe–Al–B rods. These rapidly solidified Fe–Al–B crystalline alloys, such as Fe 55Al 30B 15 as a typical sample, can show an ultra-high σ c up to ∼3 GPa and a certain plasticity (∼5%). The formation of ultrafine eutectics and solid-solution strengthening of Al substitutional solution in α-Fe are considered to be responsible for the considerable improvement of strength.