Microstructure, micro-hardness and tensile properties of Ti6Al4V manufactured by high layer-thickness wire-feed multi-laser directed energy deposition

Microstructure and micro-hardness of Ti6Al4V samples manufactured by high-layer thickness laser-directed energy deposition (LDED) were analyzed. Microstructural analysis showed surface cracks on as-printed sur-faces due to high-temperature gradient and small voids in border area between initial periphery deposition and alternate 450 deposition path. Further analysis showed overall uniform distribution of elements except for some concentrated C deposition, as confirmed by EDX mapping. Results showed micro-hardness ranging from 370.9 HV to 308.8 HV on top surface and 314.5 HV to 356.5 HV for cross-sectional surface. After the tensile test, yield stress followed a decreasing trend from 805 MPa to 710 MPa for samples 1 to 4 respectively and a similar pattern was also observed in the case of UTS ranging from 845.37 MPa to 749.9 MPa for samples 1 to 4 respectively. The present study showed proper deposition of Ti6Al4V alloy during high layer-thickness LDED manufacturing that can significantly reduce manufacturing time.

Automated summary

Microstructure and micro-hardness of Ti6Al4V samples manufactured by high-layer thickness laser-directed energy deposition (LDED) were analyzed. Surface cracks and small voids were observed on as-printed surfaces due to high-temperature gradient and deposition path. Overall uniform distribution of elements was found except for concentrated C deposition. The study also showed a decrease in yield stress and ultimate tensile strength after the tensile test.