Mechanical properties of additive manufactured titanium (Ti–6Al–4V) blocks deposited by a solid-state laser and wire

In this paper, the mechanical properties and chemical composition of additive manufactured Ti–6Al–4V blocks are investigated and compared to plate material and aerospace specifications. Blocks (seven beads wide, seven layers high, 165 mm long) were deposited using a 3.5 kW Nd:YAG laser and Ti–6Al–4V wire. Two different sets of process parameters are used and three different conditions (as-built, 600 °C/4 h, 1200 °C/2 h) of the deposit are investigated. The particular impurity levels of the blocks are considerably below those tolerated according to aerospace material specifications (AMS 4911L). Static tensile samples are extracted from the blocks in the deposition direction and punch samples are extracted in the building direction. The experiments show that as-deposited Ti–6Al–4V can achieve strength and ductility properties that fulfill aerospace specifications of the wrought Ti–6Al–4V material (AMS 4928). The 600 °C/4 h heat treatment leads to a significantly higher strength in the deposition direction, but can also decrease ductility. The 1200 °C/2 h treatment tends to decrease the alloy’s strength.

► In this paper, mechanical properties and chemical composition of deposited Ti–6Al–4V blocks are investigated. ► As-deposited Ti–6Al–4V is generally competitive to cast rather than to wrought material. ► The impurity levels are below the ones of the plate and those tolerated according to aerospace material specifications. ► A 600 °C/4 h/FC post heat treatment leads to remarkable higher strength properties in deposition direction. ► A 1200 °C/2 h/FC post heat treatment generally leads to strength properties below that of cast material.