PNNL

Abstract

During the friction surfacing (FS) process, the forge-axial force, rotation rate, and traverse speed of the consumable feed-rod significantly affect the deposition rate and layer morphology. Some researchers have explored enhancing deposition by introducing a backward tilt relative to the traverse direction. However, the exploration of other tilt directions has been limited. Therefore, this study seeks to offer a more comprehensive understanding of feed-rod tilting in FS. In the current study, the consumable feed-rod undergoes tilting in four distinct directions: forward, backward, advancing side, and retreating side. Each direction is tested at two different tilt degrees (1.5º and 3.0º). The results reveal a notable improvement in the deposition rate, increasing from 10.9 kg/h with the feed-rod normal to the substrate to 18.8 kg/h in the 3.0º forward tilt condition. This exceeds three times the maximum deposition rate of steel FS reported in existing literature. Furthermore, by using real-time videography and microstructural characterization, a physical model is established to understand the deposition dynamics with various tilt directions during FS.