Study on the recycling of 100Cr6 powder by plasma spheroidization for Laser Powder Bed Fusion

Abstract

Additive Manufacturing (AM) of steel parts is crucial in various industries such as medical, energy and transport. Laser Powder Bed Fusion (L-PBF) is a commonly used technique for producing such parts, but it can alter the properties of the unconsumed powder. This study aims to investigate the recycling of oxidized 100Cr6 powder using a plasma spheroidization process, focusing on its physical and chemical properties. The experiments reveal that the powder feed rate during spheroidization has an impact on the physical properties of the recycled powder, an optimized powder feed rate is found. Different washing and drying conditions are applied to the spheroidized powder and their influence on the powder's chemical composition is analysed through oxygen measurement. One of the washing and drying condition led to oxygen content even lower than the commercial powder. Additionally, three different hydrogen ratios in the plasma during the spheroidization process are investigated and it is found that increasing the hydrogen ratio can reduce the oxygen content in the processed powders.

Keywords

• Metal powder
• 100Cr6
• Steel
• Additive manufacturing (AM)
• Laser Powder Bed Fusion (L-PBF)
• Selective laser melting (SLM)