maps of increasing attenuation and decreasing wave speed, con- sistent with porosity increases. In this sample, it is more difficult to identify the shapes of pores through ultrasound however, it is important to note that the changes seen in the ultrasonic parameters denote sensitivity to the small pore volumes and ability to detect an increase in the concentration of pores over a large area. These relative changes in wave speed and attenua- tion could be used as feedback for optimizing printing parame- ters, such as bronze infiltration amounts, to reduce porosity. We hypothesize that other changes in the wave speed that cannot be directly linked to porosity variations are due to varying volume fractions of bronze and SS316 across the sample area. These results indicate that depending on material, ultra- sound metrics of wave speed and attenuation could prove to be valuable tools in assessing porosity. When porosity dominates the response, ultrasonic properties provide much of the same information about relative porosity as XCT. In addition, ultra- sonic data can provide insight into other microstructural features such as grain size and volume fraction of various phases. Conclusions and Future Work This study demonstrates a robust technique for identifying the porosity characteristics of binder-jetted samples using ultra- sound. The approach used simultaneously measures wave speed and attenuation to interrogate samples with distributed porosity and pore networks. Most notably, the technique accom- plishes a thickness-independent measurement for wave speed, calculates the thickness at each scanning position, and then uses this thickness to obtain more accurate measurements of absolute attenuation. When examining maps of porosity based on XCT versus maps of wave speed and attenuation, the follow- ing conclusions were drawn. In SS316L, there were large pore networks of nonuniform size distributed throughout the sample. The attenuation map identified the larger networks but was less sensitive to small variations in the relative porosity of other parts of the sample. The wave speed map showed a decrease in wave speed in the area of the largest pore network, but in other areas wave speed variations did not match well with the presence of pores. The discrepancy in wave speed correlations with porosity was attributed to large grains in SS316L likely inducing anisot- ropy. In SS316 + bronze, pores were smaller and more uniformly shaped than in SS316L, and the concentration and size of these pores increased from left to right. Wave speed and attenuation maps show a response dominated by porosity, with wave speed decreasing and attenuation increasing with increased porosity. These results underscore the applicability of UT as a character- ization method for additively manufactured samples. 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