Details

Autor(en) / Beteiligte

• Beguin, J.D.
• Balcaen, Y.
• Alexis, J.
• Andrieu, E.
• Villechaise, P.
• Appolaire, B.
• Castany, P.
• Monceau, D.
• Prima, F.
• Delfosse, J.
• Delaunay, C.
• Denquin, A.
• Millet, Y.
• Piellard, M.
• Viguier, B.
• Gey, N.
• Gloriant, T.
• Hascoët, J.-Y.
• Germain, L.
• Gautier, E.
• Pettinari-Sturmel, F.
• Dehmas, M.
• Hémery, S.

Titel

Experimental investigations for a postweld heat treatment on Ti-6Al-4V titanium welds with a defocused laser beam

Ist Teil von

• MATEC Web of Conferences, 2020, Vol.321, p.11034

Ort / Verlag

Les Ulis: EDP Sciences

Erscheinungsjahr

2020

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The purpose of this study is to apply a local heat treatment (LHT), in-situ, on the weld bead, using a defocused Yb: YAG laser beam on a continuous regime, in order to reduce residual stresses and decompose the brittle a’ martensite, into a lamellae and fine β phase. Laser scan experiments were firstly performed on a commercially pure titanium grade 2, with a wide range of parameters, in order to provide a “heat treatment window” without titanium melting. After optimization of the processing parameters, to obtain a sufficient width and depth for the scanning zone, experiments have been performed on a β-treated, fully martensitic Ti-6Al-4V sheet. For each processing experiments, the decomposition of a’, was studied based on metallographic cross sections. A local heating with a minimum energy density at 700 J.cm -2 , has a sufficient effect to destabilize a’, while for an energy density at 1000 J.cm -2 , a diffusional transformation take place, with the formation of Widmanstätten microstructure. Finally, these optimized conditions were applied on a full penetration Ti-6Al-4V welds. The results of the LHT will be described in terms of the microstructural changes observed in the welded zone and hardness evolution.