Effect of electropolishing on mechanical property enhancement of Ti6Al4V porous materials fabricated by selective laser melting

ABSTRACT

Metal additive manufacturing technologies such as laser powder bed fusion (so-called selective laser melting) have been widely applied in the field of aerospace or medical device. Moreover, porous materials have been extensively studied due to the maturity of metal additive manufacturing technology. The stress shielding effects can be reduced and the bone integration between the human bones and medical devices can be improved by introducing porous materials. Thus, the medical device would be more stable after implantation. However, in our previous study, the mechanical properties of porous materials are not only affected by the porous structure and porosity but also affected by the surface roughness and the ratio between surface roughness and strut diameter. In this study, to investigate and explore such issues, two major topics will be researched, which are (1) the formulation development of the electrolyte with a surfactant to increase the surface finish effectiveness during the electropolishing process of 3D printed Ti-6Al-4V porous materials; (2) the exploration of the relationship between the mechanical properties and the surface roughness/other factors. Also, the effect of surface roughness on mechanical properties was evaluated in terms of work of fracture and specific energy absorption.

KEYWORDS:

• Additive manufacturing
• laser powder bed fusion
• selective laser melting
• Ti–6Al–4V
• electropolishing
• mechanical property
• work of fracture
• specific energy absorption
• electropolishing

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors gratefully acknowledge the sponsorship support from Ministry of Science and Technology Taiwan, ROC [grant number MOST 109-2218-E-110-011] and [grant number MOST 109-2622-E-110-013].

Notes on contributors

Che Nan Kuo

Che-Nan KUO is an Assistant Professor in the Department of Materials and Optoelectronic Science, National Sun Yat-sen University, Kaohsiung, Taiwan. He received his PhD from Department of Materials and Optoelectronic Science, National Sun Yat-sen University in 2013. He conducted metal 3D printing research and built up the Electron Beam Additive Manufacturing Laboratory at Metal Industries Research & Development Centre from 2013 to 2017 before taking his position at Asia University. Prof. Kuo was conducted research in 3D Printing Medical Research Institute hosted at Asia University, Taichung, Taiwan (from 2017 to 2021). He was also the head of the Selective Laser Melting Laboratory at the 3D Printing Medical Research Center, China Medical University Hospital, Taichung, Taiwan. His current research focuses on the 3D printing parameter development of advanced metallic materials, mechanical behaviour of porous materials, development and optimization of post/heat treatments for porous materials, and the microstructure evolution research of advanced materials during/after 3D printing process.

Yu Ping Wang

Yu-Ping Wang, Ph. D joined Prof. Kuo's Metal 3D Printing and Advanced Materials Laboratory in 2017. She received her master from the Department of Bioinformatics and Medical Engineering, Asia University in 2019. She is currently pursuing a Ph. D in the Department of Materials and Optoelectronic Science, National Sun Yat-sen University. Her current research focuses on the 3D printing parameter development of metallic materials and the mechanical behaviour of porous materials.

Chee Kai Chua

Chee Kai Chua is the Head of Pillar for Engineering Product Development and Cheng Tsang Man Chair Professor at the Singapore University of Technology and Design (SUTD), Singapore. Prof Chua is an active contributor to the field of additive manufacturing (or 3D printing) for over 30 years and is highly regarded by the scientific community. He won the prestigious International Freeform and Additive Manufacturing Excellence (FAME) Award in 2018. Prof Chua is also the Editor-in-Chief of “Virtual and Physical Prototyping” and “International Journal of Bioprinting”. As of June 2021, he has contributed more than 400 technical papers, generating more than 16,000 citations (with h-index of 65), and co-authored five books including “3D Printing and Additive Manufacturing: Principles and Applications (5th edition)” and “Bioprinting: Principles and Applications”.