Effect of ultrasonic peening on Microstructure and properties of laser rapid forming GH4169

A new hybrid process of laser rapid forming (LRF) assisted by ultrasonic shot peening (LRF-USP) is proposed to improving the tensile and stress rupture properties at laser rapid forming. Based on mechanism analysis of laser rapid forming and ultrasonic shot peening, a processing model of LRF-USP is built. The special experimental equipments were designed and made. Forming experiments on the Nickel-based superalloy powders were conducted with the equipments, and the samples were analyzed by scanning electronic microscopy (SEM) and energy dispersive spectrometer (EDS). The result shows that theoretical model and experimental results are identical well with each other. During LRF-USP, USP can refine grain sizes and eliminate the residual tensile stress produced by LRF, forming a residual plastic field with compressive stresses.