Metal fiber composite body

PROBLEM TO BE SOLVED: To provide a metal fiber composite, e.g. concrete or a refractory material, which is produced by increasing the fracture energy by a mechanism different from conventional fracture energy increasing mechanisms and has fracture energy higher than that attained by a drawing effect.SOLUTION: A metal-fiber composite is formed by adding a metal fiber which has an elongation at the maximum load of 10% or higher and a maximum tensile strength, or a ratio of maximum load/fiber cross section, of 350 MPa or higher, in a uni-axial tensile test. The metal fiber has a surface roughness Ra of 0.1 μm or greater and a maximum height Rz of 1.3 μm or greater.