Effect of heat treatment on the corrosion resistance and mechanical properties of selective laser melting Ti6Al4V alloy

• Published in: Materialwissenschaft und Werkstofftechnik 2021-12, Vol.52 (12), p.1319-1327
• Main Authors: Sui, A.Q., Liu, B.J., Liu, C.H., Wang, D.S., Wang, E.L.
• Format: Article
• Language: English
• Subjects: Corrosion effects; Corrosion resistance; Corrosion tests; Electrochemical corrosion; Grain size; Heat treatment; Korrosionsbeständigkeit; Laser beam melting; Lasers; Mechanical properties; mechanische Eigenschaften; Rapid prototyping; Selective laser melting; Selektives Laserstrahlschmelzen; Strain; Ti6Al4V; Titanium base alloys; Wärmebehandlung
• ISSN: 0933-5137; 1521-4052
• DOI: 10.1002/mawe.202100201

The present work shows that the effect of several heat treatments on the corrosion resistance and mechanical properties of Ti6Al4V processed by selective laser melting (SLM). The microstructure of Ti6Al4V alloy produced by selective laser melting exhibited bulky prior β columnar grains, and a large amount of fine acicular martensites α′ were observed inside the prior β columnar grains. The acicular martensitic α′ were transformed to a mixture of α and β after heat treatment, and the grain size increases with the increase of heat‐treated temperature. The results of 3.5 wt% NaCl solution electrochemical corrosion test showed that the heat‐treated samples possess a higher corrosion resistance than the as‐received sample. Among of them, the sample after heat‐treated at 730 °C exhibited best corrosion resistance and excellent fracture strain. The sample heat treated at 1015 °C showed worst mechanical properties due to the formation of Widmanstätten structure. The high density Ti6Al4V alloy was successfully produced by selective laser melting (SLM). The microstructure transformed into a α+β mixture after heat‐treated. Improved corrosion resistance of heat‐treated SLM‐produced Ti6Al4V alloy samples were obtained. The heat‐treated sample at 730 °C exhibited excellent corrosion resistance and plastic.