Ultrasonic Assessment of the Effect of Manufacturing Parameters on the Variability Within Additively Manufactured 316L Samples

Additive manufacturing using laser powder bed fusion has the ability to produce objects with complex shapes with a high accuracy and resolution. The material properties of additively manufactured products are dependent on the process parameters, and it is important to carefully consider and control these parameters to achieve the desired properties. In this paper, 27 steel samples were additively manufactured based on a three-level factorial design by changing speed, hatch distance and power. Ultrasound scans were recorded from these samples using a 5 MHz focused transducer and the backscattered signals were used to quantify the within sample variance of these cubes. The variation metric and the manufacturing parameters were converted into a response surface model to evaluate the significance of each process parameter and the interaction between them. The results show that each process parameter has an impact on the within sample variance and these parameters can be optimized to achieve a homogeneous micro-structure.