A high temperature phased array ultrasonic roller probe designed for dry-coupled in-process inspection of wire + arc additive manufacturing

This research aims to propose a novel design for a high-temperature ultrasonic roller probe that can be employed on unmachined surfaces of Wire + Arc Additive Manufactured components to detect near-surface defects. An initial concept for the roller probe is devised, and material selection for different components of the roller probe is carried out considering the required mechanical, thermal and acoustic properties. The dimensions of the roller probe and its parts are determined according to the expected performance of the roller probe. The numerical finite element method is used to investigate the roller probe’s tire thickness for a fixed duty cycle of inspection at a temperature of 350˚C. The roller probe performance for inspection of a defective Ti-6Al-4V WAAM sample is assessed at room temperature. The dry-coupled roller probe successfully detected a 1.5mm flat bottom hole located at a depth of 5 mm under the unmachined WAAM surface.