Deformation Characteristics of Fine Protrusions Formed by Sputter-Etching of Stainless Steels

Abstract

Sputter-etching was applied to type 303, 304, 430 and 420 stainless steels to form conical or ring-shaped protrusions on the surface, and the tensile test of the substrate with protrusions, the press and scratch tests of protrusions were carried out. The tensile test shows that the conical protrusion is ductile, and the delamination and dropping out of the protrusions from substrate never occur before fracture of the substrate. The press test of the protrusions reveals that the conical protrusion is so strong to form deep hole on the counter rod of aluminum alloy although the tip of the protrusion is flattened. The scratch test of the surface with conical protrusions shows a large change of friction force with increasing scratch distance, whereas relatively small change of friction force for ring-shaped protrusions due to a smaller height and a narrow space between each ring wall. The maximum scratch force for a typical conical protrusion is about 40mN.