Investigation of ultrasonic impact with electro-spark melting treatment on surface modification of DH36 steel

The DH36 steel was conducted surface treatment by the UIEMT (ultrasonic impact with electro-spark melting treatment). And the contrastive study of surface properties was also carried out between the UIEMT treated sample and UIT (ultrasonic impact treatment) treated sample. Compared with the UIT treated sample, the results indicated that the thickness of surface plastic deformation layer of the UIEMT-treat sample was increased and a fine grain microstructure with a depth of about 25 μm was formed in the surface. The surface hardness increased by 65.1%. The hardened case depth was up to 55 μm, and the surface roughness reduced by 79.6%. The wear volume loss reduced and the wear failure mechanism presented adhesive wear for UIEMT treated sample. Compared with UIT treatment, the surface hardness, wear resistance and surface roughness of the samples treated by UIEMT further improved.