https://orcid.org/0000-0002-0748-8649
![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
ABSTRACT
Green density of binder jetted parts are typically equal or lower than the powder tap density. Also, anisotropic green porosity distribution is expected because of the characteristics of the binder jetting (BJ) printing process. In this study, the microstructure evolution in terms of phases and porosity characteristics was studied. A transition from irregular-shape interconnected porosity in pre-sintered samples to closed quasi-spherical porosity for samples sintered at 1370°C was observed. EBSD phase map showed ∼2.73% of δ-ferrite in sample sintered at 1370°C. The anisotropic porosity distribution was revealed by a higher area fraction of aligned large pores (>35 µm), within the cross-section perpendicular to the building direction. Chemical analysis showed an increase of C, O and N on the green sample, while a strong decrease was found after sintering when compared with the powder chemistry. δ-ferrite onset, from phase equilibrium calculations, varies from ∼1250°C (sintered sample chemistry) to ∼1350°C (powder chemistry).
Acknowledgement
This work was conducted in the framework of the Centre for Additive Manufacturing – Metal (CAM2), supported by the Swedish Governmental Agency of Innovation Systems (Vinnova).
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Notes on contributors
Alberto Cabo Rios
Alberto Cabo Rios is currently a Ph.D. Student at the Department of Industrial and Materials Science, Chalmers University of Technology, Sweden, with focus on experimental studies of sintering of metallic components produced by binder jetting additive manufacturing. Also, he is a research visitor in the powder technology laboratory (PTL), Mechanical Engineering Department at San Diego State University (SDSU), with focus on the advanced multi-physics modelling of sintering of components produced by binder jetting.
Eduard Hryha
Eduard Hryha received his Ph.D. degree in Materials Engineering in 2008 from the Institute of Materials Research of the Slovak Academy of Sciences, Slovakia. He is currently a full professor at the Department of Industrial and Materials Science, Chalmers University of Technology. His main research activity is devoted to powder metallurgy and additive manufacturing.
Eugene Olevsky
Eugene Olevsky received his Ph.D. from Ukraine National Academy of Sciences in 1990. Since 1998, he has been a faculty member of the Mechanical Engineering Department at San Diego State University. He is the Dean of the College of Engineering since March 2018. His main research activity is devoted to experimentation and computational modelling on powder processing, including novel ceramic, metallic, composite materials synthesis, field-assisted sintering techniques and sintering-assisted additive manufacturing.
Peter Harlin
Peter Harlin received his Ph.D. degree in Materials Science in 2008 from Chalmers University of Technology, Sweden. He is currently research leader at the Department of Powder R&D at Sandvik Additive Manufacturing and adjunct senior lecturer at the Department for Subtractive and Additive Manufacturing at University West. His main research activity is devoted to powder metallurgy with focus on metal additive manufacturing.