Indentation-derived mechanical properties of Ti-6Al-4V: Laser-powder bed fusion versus electron beam melting

Abstract Employing a depth-sensing indentation testing technique, the room temperature mechanical properties of Ti-6Al-4V (Ti64) alloy fabricated through laser powder-bed fusion (L-PBF) and electron beam melting (EBM) additive manufacturing processes were studied. Mechanical properties including nano-hardness (in GPa), reduced elastic modulus, yield pressure, elastic recovery, and wear resistance were extracted. The microstructure of the fabricated materials was correlated with the indentation-derived characteristics. It was observed that the nano-hardness and reduced elastic modulus values were 3.66 ± 0.06 GPa and 118 ± 3 GPa, for the L-PBF, and 3.43 ± 0.22 GPa and 136 ± 4 GPa, for the EBM materials, respectively. The higher strength of the L-PBF alloy is due to the finer microstructure of this alloy. While α laths with an average width of 3.61 ± 0.92 μm developed in the EBM-Ti64, the microstructure of L-PBF-Ti64 consisted of α′ martensite with an average width of 0.37 ± 0.10 μm.