Influence of Laser Treatment on the Creep of the Ti-6Al-4V Alloy

Titanium and its alloys are excellent materials for structural applications in components submitted to high temperatures because of their high strength, weight ratio, good corrosion resistance, and microstructural stability. However, the affinity to oxygen is one of the main factors that limit their application as structural materials at high temperatures. The objective of this work was to estimate the influence of laser treatment on the creep of a Ti-6Al-4V alloy. Constant load creep tests were conducted at 873 K (600 A degrees C) in a standard creep machine at a stress of 125 to 319 MPa. Samples with a gage length of 18.5 mm and a diameter of 3.0 mm were used for all tests. It was observed that the effect of the oxidation was smaller and the behavior of the creep curves showed that the life time in laser treated samples was better than in the received samples. An increase of ductility of final strain and in the lifetime for the laser-treated material was observed. The decrease of the steady-state creep occurred in conjunction with the oxidation process reduction, showing that for the Ti-6Al-4V alloy, the lifetime is affected strongly by the laser treatment with an increase in this superficial protection.