The effect of Ti content on microstructure and tensile properties of 6070 Al Alloy after and before extrusion

To investigate the effect of adding Ti on microstructure and tensile properties after and before extrusion, different amounts of Ti (0.01-0.5 wt. %) by means of Al-5Ti-1B master alloy added to 6070 Al molten. Microstructural study, fractography and mechanical properties were done by optical microscopy, scanning electron microscopy (SEM) and tensile test in both unrefined and Ti-refined conditions. The experimental results show that the great effect can be obtained after the addition of 0.03 wt.% Ti into the alloy. The average grain size decreased from 856 to 149 μm, while the morphology of primary α–Al was remained dendritic. Moreover, UTS and elongation increased from 212 to 234 MPa and 4.2 to %6.5, respectively. Extrusion increased UTS and elongation values of all specimens. A comparison between tensile properties of free Ti specimen and the specimen containing 0.03 wt.% Ti separately after extrusion revealed that the UTS increased from 241 to 257 MPa and the elongation improved from 18.2 to %20.3. The reason for this improvement is due to reduce in the grain size of the alloy by adding Ti, which is resulting in finer and more uniform distribution of second phase after extrusion

کلیدواژه ها:

Al-5Ti-1B master alloy ، Al-Mg-Si alloy ، Refinement ، Extrusion