Wear Properties of Surface Modified Hard Layers Using Electrical Discharge Machine

Abstract

Recently hard layers have tried to be formed using electrical discharge machines (EDMs) which are mainly used now for material removal. The time and cost of producing dies and machine parts can be greatly reduced when the same EDM is used as the main plant machine in die making and surface modification. The wear properties of hard layers formed on stainless steel using EDM were studied. As a result, it was found that surface layers modified with both titanium hydride (TiH2) green-compact electrodes and titanium carbide (TiC) semi-sintered electrodes had a hardness of about 2,600 HV, and a surface roughness of 10 to 13 μmRy. And the coating thickness of a surface layer modified with a TiH2 electrode was 12 μm, but the coating thickness of a surface layer modified with a TiC electrode was thinner at 2 μm. However the hard layers formed with TiH2 electrodes were three to four times more wear resistant and the layers formed with TiC electrodes were about ten times more wear resistant than surfaces without a hard layer.

Keywords

• coating
• wear
• electrical discharge machining
• surface treatment
• measurement