Changes in surface integrity of cemented tungsten carbide with shot peening treatment

• Published in: Surface & coatings technology Vol. 425; p. 127710
• Main Authors: Wang, Chengxi, Zhang, Hao, Xiong, Xiao, Li, Mengnie, Chen, Ming, Liu, Huabing, Jiang, Chuanhai
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.11.2021; Elsevier BV
• Subjects: Cemented carbides; Cemented tungsten carbide; Compressive properties; Elastic deformation; Hardness; Integrity; Plastic deformation; Residual stress; Shot peening; Surface integrity; Surface layers; Surface roughness; Tungsten carbide; Surface integrity; Shot peening; Surface roughness; Hardness; Residual stress; Cemented tungsten carbide
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2021.127710

This study investigates the changes in the surface integrity of WC-Co cemented carbide, after traditional and dual shot peening treatments, using physical characterization methods in conjunction with finite element simulations. Cast steel balls were used in traditional shot peening, while dual shot peening involved the additional use of ceramic shots. Tensile residual stress was found to coexist with compressive residual stresses within both the WC and Co phases, resulting in the fluctuation of stress amplitude in the surface layer. Steep stress gradients were mainly located in regions near the phase interface, especially around the WC/Co interface. In comparison with traditional shot peening, dual shot peening not only improved the uniformity of residual stress at both the macroscopic and microscopic levels but also refined the microstructure and returned the hardness dispersion to the original value by facilitating the simultaneous and coordinated evolution of the WC and Co phases during further deformation. However, the surface roughness increased significantly after traditional and dual shot peening treatments due to accumulated elastic-plastic deformation. This is likely to deteriorate the surface integrity and thus should be avoided if possible, without compromising the other beneficial effects caused by shot peening. [Display omitted] •Compressive residual stress and hardness increased after shot peening treatment.•Tensile and compressive residual stress coexist in WC and Co phases.•Uniformity of macro and micro residual stress improved after dual shot peening.•Traditional shot peening increases but dual shot peening reduces hardness dispersity.•All types of shot peening deteriorate surface roughness.