The ageing response of direct laser deposited metastable β-Ti alloy, Ti–5Al–5Mo–5V–3Cr

• Published in: Additive manufacturing Vol. 48; p. 102384
• Main Authors: Sharma, Deepak, Kada, Sitarama Raju, Fabijanic, Daniel, Parfitt, David, Chen, Bo, Roebuck, Bryan, Fitzpatrick, Michael E., Barnett, Matthew Robert
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2021
• Subjects: Direct laser deposition; Microstructure-property relationship; Single and duplex aging; Titanium alloys; Titanium alloys; Single and duplex aging; Microstructure-property relationship; Direct laser deposition
• ISSN: 2214-8604; 2214-7810
• DOI: 10.1016/j.addma.2021.102384

The formation of solely β-phase titanium after direct laser deposition (DLD) of metastable β-Ti alloy does not provide the desired properties. Hence, we present a study into the ageing response of DLD built Ti-5553 β-Ti alloy to obtain the bimodal (β + α) microstructure providing improved properties. The results obtained from the heat treatments showed that a unique microstructure with refined intragranular and discontinuous grain boundary α-phase can be obtained by directly ageing (using fast heating rate) the as-built samples at the ageing condition (600 °C + 0.5 h). This microstructure produced a good balance in mechanical properties (UTS = 1345 ± 5 MPa and δ = 11.6 ± 0.5%). The interparticle spacing between the α-phase (d) showed a correlation with microhardness (Hv=340+158/√d) and yield stress (σ0.2=870+15086/√d) values for all the aged samples.