Development of the Ultrasonic System Integration With 3D Polymer Printing

Non-destructive testing using ultrasonic sensors supplies manufacturers with methods of monitoring a part’s integrity as it is being produced. The purpose of this experiment is to demonstrate the usefulness and viability of using ultrasonic sensors to monitor the 3D printing process. In order to accomplish this task, an attachment for the build plate of a 3D printer was developed that holds an ultrasonic sensor against the build plate while the printer is running initial tests. The ultrasonic sensor was used to analyze printing filaments and the build plate included with the printer. The results of ultrasonic investigation have demonstrated inefficiency of the composite plate in transduction of elastic waves and a steel build plate was suggested for further testing. Initial studies were conducted to explore material characteristics of the built plates and the printing materials. Ultrasonic setup with longitudinal and shear wave transducers were utilized to measure material properties such as Young’s modulus, shear modulus and the Poisson ratio. It is anticipated that material characterization will also be conducted during the printing process. This means heat will be introduced into the system and as a result the speed of sound through the build plate and filament will vary as a function of temperature. To better understand the role of temperature in real-time ultrasonic NDE, an FEA model is developed to determine the transient temperature gradient through the steel build plate and filament during the printing process. Thermal imaging data is considered to assess the accuracy of the FEA model for the dynamic temperature distribution. Once relationships between temperature variation and sound speed have been established properties such as Young’s modulus can be calculated. It is anticipated that application of this approach will allow for assessment of material properties in near real time, which is critical for process monitoring and ensuring quality of the additively manufactured parts.