The full fabrication time in laser powder bed fusion (LPBF) can range from a couple of hours to several days depending on the complexity of the part. During the build cycle, both planned process interruptions (such as powder refill) and unplanned process interruptions (such as power outages) can occur that may last up to several hours. A decision must be made, typically based on project guidelines rather than data driven analysis, of whether to restart the build from that point or start it from the beginning. The restart usually results in the part exhibiting a seam line. The problem is that there is no knowledge available in the public domain detailing the effects of build interruptions on the properties of the resulting parts.
The objective of the project is to develop a comprehensive data set of build interruptions for two commonly used alloys (AlSi10Mg and IN625) processed with LPBF. The compiled data sets can be used by government and industry to decide whether it is best to resume the fabrication process or to start the build from the beginning. Considerations include the microstructure and material properties of the component as well as fabrication cost and time.
The project aims to characterize build interruption effects and develop recovery procedures for two materials (AlSi10Mg and IN625) that have a wide base of industrial applications. Two commercially available LBPF systems (SLM 125 HL and AconityONE) will be used to produce samples for testing.
Phase I will characterize the effects to the microstructure and mechanical properties arising from build interruptions on both the SLM 125 HL and AconityONE systems using AlSi10Mg material. At the end of Phase I, a comparison of the results on the different systems for this material will be completed.
Phase II will provide similar characterization and monitoring methodology for IN625 processed on the SLM 125 HL system. Upon completion of this phase, the comparison of build interruptions using both materials (AlSi10Mg and IN625) on the SLM 125 HL will be concluded.
- U.S. Air Force