Yongda Ye

Effects of electropulsing assisted ultrasonic impact treatment on welded components

Abstract The effect of electropulsing assisted ultrasonic impact treatment (EUIT) on the mechanical properties and microstructure evolution of S50C steel welded components has been investigated. The present paper presents the application of a relatively new post-weld treatment method to eliminate the residual stress and improve the surface mechanical properties. The results show that EUIT exhibits better surface modification capability than does conventional ultrasonic impact treatment. After EUIT, plastic deformation layer with strengthened grains formed on the sample surface, and residual tensile stress was converted into residual compressive stress.

Effect of electropulsing-assisted turning process on AISI 5120 cementation steel

ABSTRACT Electropulsing was used to aid in the cutting process of the AISI 5120 cementation steel. Electropulsing is found, on the one hand, to significantly decrease the main cutting force and reduce the tool wear and, on the other hand, to largely improve the surface quality and surface hardness of the specimen. Electropulsing showed remarkable improvement in plastic deformation ability and cutting properties by inducing lubrication property. This phenomenon can be explained by the enhanced mobility of dislocations that resulted from the electroplastic effect and Joule heating. This paper is part of a themed issue on Materials in External Fields.

Enhanced Surface Mechanical Properties and Microstructure Evolution of Commercial Pure Titanium Under Electropulsing-Assisted Ultrasonic Surface Rolling Process

The effects of electropulsing-assisted ultrasonic surface rolling process on surface mechanical properties and microstructure evolution of commercial pure titanium were investigated. It was found that the surface mechanical properties were significantly enhanced compared to traditional ultrasonic surface rolling process (USRP), leading to smaller surface roughness and smoother morphology with fewer cracks and defects. Moreover, surface strengthened layer was remarkably enhanced with deeper severe plastic deformation layer and higher surface hardness. Remarkable enhancements of surface mechanical properties may be related to the gradient refined microstructure, the enhanced severe plastic deformation layer and the accelerated formation of sub-boundaries and twins induced by coupling effects of USRP and electropulsing. The primary intrinsic reasons for these improvements may be attributed to the thermal and athermal effects caused by electropulsing treatment, which would accelerate dislocation mobility and atom diffusion.