Abstract: A surface-alloyed cylindrical, partly cylindrical or hollow cylindrical component consists of an aluminium matrix casting alloy (1) and a precipitation area (3) extending as far as the surface of the component (3) and consisting of an aluminium base alloy with precipitated hard phases. A eutectic area (2) (hereafter: “transition area”) which is supersaturated by primary hard phases is present between the matrix (1) and the precipitation area (3) and the increase in hardness from the matrix (1) to the component surface (3) is gradual.

Abstract: Surface-alloyed cylindrical, partly cylindrical or hollow cylindrical structural member, consisting of an aluminium matrix casting alloy and a precipitation zone extending as far as the upper surface of the structural member, comprising an aluminium based alloy with precipitated hard phases, where between the matrix and the precipitation zone there is a eutectic zone supersaturated by primary hard phases (hereinafter called the transition zone) and the increase in hardness from the matrix to the surface of the structural member takes place stepwise.