Dynamic compressive behaviour of Ti-6Al-4V alloy processed by electron beam melting under high strain rate loading

Abstract

This paper documents an investigation into the compressive deformation behaviour of electron beam melting (EBM) processing titanium alloy (Ti-6Al-4V) parts under high strain loading conditions. The dynamic compression tests were carried out at a high strain rate of over 1×10³/s using the split Hopkinson pressure bar (SHPB) test system and for comparison the quasi-static tests were performed at a low strain rate of 1×10⁻³/s using a numerically controlled hydraulic materials test system (MTS) testing machine at an ambient temperature. Furthermore, microstructure analysis was carried out to study the failure mechanisms on the deformed samples. The Vickers micro-hardness values of the samples were measured before and after the compression tests. The microstructures of the compressed samples were also characterized using optical microscopy. The particle size distribution and chemical composition of powder material, which might affect the mechanical properties of the specimens, were investigated. In addition, the numerical simulation using commercial explicit finite element software was employed to verify the experimental results from SHPB test system.

Keywords

Additive manufacturing / Electron beam melting (EBM) / Titanium alloys / Split Hopkinson pressure bar (SHPB) / Compressive stress / Numerical simulation / Scanning electron microscope (SEM)

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Funding

VDMC