Effect of AlSi10Mg0.4 long-term reused powder in PBF-LB/M on the mechanical properties

• Published in: Materials & design 2021-12, Vol.212, p.110176, Article 110176
• Main Authors: Fiegl, Tobias, Franke, Martin, Raza, Ahmad, Hryha, Eduard, Körner, Carolin
• Format: Article
• Language: English
• Subjects: Aluminum; Enlarged build envelope; Mechanical properties; Powder bed fusion process; Powder degradation
• ISSN: 0264-1275; 1873-4197; 1873-4197
• DOI: 10.1016/j.matdes.2021.110176

[Display omitted] •The content of oxygen and hydrogen increases with increasing level of powder degradation in PBF-LB/M process.•Samples made of long-term reused powder display quadruplicated porosity compared to virgin powder samples.•Long-term reused powder reduces tensile and yield strength as well as elongation at break about 15%.•Oxygen content of processed powder plays an important role in pore formation of manufactured components. Laser-based powder bed fusion (PBF-LB/M) is a well-established additive manufacturing (AM) process capable of producing high quality parts with excellent mechanical properties. Industrial applications of additively manufactured parts require the usage of fresh powder which makes the process expensive, especially in case of AM machines with enlarged build envelopes. Processing long-term reused powder fits to economic yields with the drawback of increased porosity and incorporated oxides. In this study, a detailed analysis of components made of virgin and long-term reused AlSi10Mg0.4 powder is provided. The experiments reveal that process parameters qualified for the virgin powder are not working offhand for the reused powder, as an increase of porosity from less than 1% up to 3% and a decline of tensile strength as well as yield strength of about 15% are observed. The results indicate that powder degradation, which is based on the formation of hydroxides and oxides, has a significant impact on as-built microstructure as well as mechanical properties of additively manufactured parts. The amount of hydrogen and oxygen is measured for different powder conditions and the powder ageing process of AlSi10Mg0.4 is discussed in detail.