Study on flaking behavior in Selective Laser Melting process

摘要

Selective Laser Melting (SLM) technology has been increasingly used in manufacturing medical, aerospace, automotive components due to its nearly full density products, material flexibility, freely design. However, the SLM process requires the strict conditions with highly appropriate process parameters to achieve desirable properties meet the products' quality requirements and avoid some processing disruptions especially the flaking phenomenon. Affected by the inappropriate processing parameters, consolidation of metal powder and quality of final parts, flaking behavior is the phenomenon that product formed by the several layers since beginning peels on the surface of the substrate. This anomaly as bendy metal plate impedes the printing process by conflicting with the plastic scrapper and therefore the product quality. This paper aims to analyze the flaking phenomenon which mostly articles neglected on the SLM process. Product quality of pure aluminum cubes were investigated by temperature gradient mechanism analyzing and find out the appropriate process parameters to eliminate the unexpectedly flaking behavior. The 10mm cubic parts of 99,9% aluminum material were printed on the AISI 1045 steel substrates without support section in a chamber which filled by argon gas for maintaining the oxygen degree at 0.5 percent. Results illustrate that the flaking behavior has a significant influence on the SLM process continuance and printed part quality. The time of behavior appearance and process discontinuance depends on both process parameters and the thickness of several first layers. The paper also demonstrates the appropriate process parameters to eliminate the flaking. This is the first study which considers the effects of the flaking behavior on the SLM process. The results can be applied for process controlling purpose as well as quality improving SLM parts.