TY - JOUR
T1 - Predictive analytical modelling and experimental validation of processing maps in additive manufacturing of nitinol alloys
AU - Zhu, Jia Ning
AU - Borisov, Evgenii
AU - Liang, Xiaohui
AU - Farber, Eduard
AU - Hermans, M. J.M.
AU - Popovich, V. A.
PY - 2021
Y1 - 2021
N2 - Nitinol (NiTi) shape memory alloys fabricated by Laser Powder Bed Fusion (L-PBF) Additive Manufacturing (AM) have attracted much attention in recent years, as compared with conventional manufacturing processes it allows to produce Nitinol parts with high design complexity. Avoidance of defects during L-PBF is crucial for the production of high quality Nitinol parts. In this study, analytical models predicting melt pool dimensions and defect formation criteria were synergistically used to develop processing maps demonstrating boundary conditions for the formation of such defects, as balling, keyhole-induced pores, and lack of fusion. Experimental validation has demonstrated that this method can provide an accurate estimation and guide manufacturability of defect-free Nitinol alloys. Moreover, the crack formation phenomena were experimentally analysed, which showed that a low linear energy density (El) should be chosen to avoid cracks in the optimized process windows. Based on model predictions and experimental calibrations, Nitinol samples with a relative density of more than 99% were successfully fabricated.
AB - Nitinol (NiTi) shape memory alloys fabricated by Laser Powder Bed Fusion (L-PBF) Additive Manufacturing (AM) have attracted much attention in recent years, as compared with conventional manufacturing processes it allows to produce Nitinol parts with high design complexity. Avoidance of defects during L-PBF is crucial for the production of high quality Nitinol parts. In this study, analytical models predicting melt pool dimensions and defect formation criteria were synergistically used to develop processing maps demonstrating boundary conditions for the formation of such defects, as balling, keyhole-induced pores, and lack of fusion. Experimental validation has demonstrated that this method can provide an accurate estimation and guide manufacturability of defect-free Nitinol alloys. Moreover, the crack formation phenomena were experimentally analysed, which showed that a low linear energy density (El) should be chosen to avoid cracks in the optimized process windows. Based on model predictions and experimental calibrations, Nitinol samples with a relative density of more than 99% were successfully fabricated.
KW - Analytical model
KW - Defect formation
KW - Laser powder bed fusion
KW - Nitinol alloys
KW - Process optimization
UR - http://www.scopus.com/inward/record.url?scp=85098475179&partnerID=8YFLogxK
U2 - 10.1016/j.addma.2020.101802
DO - 10.1016/j.addma.2020.101802
M3 - Article
AN - SCOPUS:85098475179
SN - 2214-8604
VL - 38
JO - Additive Manufacturing
JF - Additive Manufacturing
M1 - 101802
ER -