The effect of varying process parameters on the Microhardness and Microstru Cu-steel and Al-Al2o3 friction joints

Abstract

Varying the rotational speed and forging pressures during friction welding affect the joint properties differently. C11000 copper to AISI 1030 mild steel (Cu-steel), and 6061 aluminum to alumina (Al-Al2O3) friction joints were fabricated on a direct drive friction welding machine. Microhardness traverses across the joint showed lower copper hardness, and higher steel hardness compared to the parent material, when 900 rpm rotational speed as used. This trend is reversed when the rotational speed is increased to 1800 rpm. Grain structure distortation was confined to an area of < 0.5 mm from the joint interface. Microhardness traverses across the Al-Al2O3 joint could not yield much information due to the influence of porosity on the microhardness readings. The results indicate that microhardness test is not appropriate for the characterization of Al-Al2O3 friction joints.