Indentation strain rate sensitivity of laser-powder bed fused and electron beam melted Ti–6Al–4V. (January 2022)

• Record Type: Journal Article
• Authors: Chandra Kaushik, Harish; Shakil, Shawkat Imam; Amirkhiz, Babak Shalchi; Mohammadi, Mohsen; Asadi, Ebrahim; Haghshenas, Meysam; Hadadzadeh, Amir
• Is Part Of: Vacuum. Volume 195(2022)
• Publication Date: 2022-01
• Subjects: Indentation strain rate sensitivity -- Additive manufacturing -- L-PBF -- EBM -- Ti–6Al–4V; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2021.110690
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Indentation hardness ( H i n ) and strain rate sensitivity (SRS) of additive manufactured Ti–6Al–4V (Ti64) alloys fabricated through both laser powder bed fusion (L-PBF) and electron beam melting (EBM) are investigated. One major difference between these processes is the higher cooling rates associated with the L-PBF. The indentation tests were performed at loading rates of 1, 10, and 50 mN/s. The L-PBF alloy showed a higher hardness value (3.45 GPa at 1 mN/s, 3.57 GPa at 10 mN/s, and 3.66 GPa at 50 mN/s) being correlated with its finer grain structure as compared with the EBM counter material (3.12 GPa at 1 mN/s, 3.37 GPa at 10 mN/s, and 3.55 GPa at 50 mN/s). The indentation SRS was explained based on the print orientation and dislocation density. EBM-Ti64 shows a higher SRS (0.0335 compared with 0.0147 in the L-PBF alloy) due to the rotation of α-prismatic planes along the building direction. Highlights: L-PBF and EBM techniques were used to fabricate Ti64 samples EBSD was employed to study the microstructure of the alloys The rate-dependent micromechanical properties of the samples were evaluated using nanoindentation The strain rate sensitivity of the alloys was correlated to the microstructure and texture