Accurate monitoring of additive manufacturing quality using non-specular reflection of bounded ultrasonic beams

This study introduces a viable methodology that leverages the phenomenon of non-specular reflection of bounded ultrasonic beams within a liquid-solid plate-liquid configuration to precisely monitor the quality of components produced through additive manufacturing (AM). The investigation delves into the relationship between non-specular reflection and some key parameters, including the degradation of AM components' quality and the incident angle of bounded ultrasonic beams. Through a detailed exploration of the propagation behaviors of bounded ultrasonic beams within a water-AM components-water configuration via finite element (FE) simulations, it becomes evident that the specular reflection coefficient (SRC) serves as a pivotal indicator of the non-specular reflection phenomenon. Notably, the simulation results indicate that the change rate of SRC at the S0 critical angle (CR_S0) reveals a significant, monotonically increasing sensitivity to the degradation in the quality of AM components. This discovery unveils a robust approach for precisely monitoring the quality of AM components. Furthermore, the experimental result also demonstrates that the parameter CR_S0 exhibits highly sensitive characteristics to the degradation in the quality of AM components when a bounded ultrasonic beam is incident at the S0 critical angle onto the AM components. Concurrently, the presence of irregular holes on the surface of AM components, as shown by the metallographic analysis result, substantiates the effectiveness of the parameter CR_S0. This investigation affirms that the CR_S0-based method is a feasible non-destructive evaluation one for accurately monitoring the quality of AM components.