کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1581640 | 1514859 | 2009 | 5 صفحه PDF | دانلود رایگان |
The effects of yttrium additions on plastic deformability and the change of microstructures after deformation of TiAl alloys were investigated by isothermal hot-compression pressing. The experiments were conducted with the Gleeble-1500D style of thermo-force analogue machine. The results indicated that the higher the deformation temperature and the lower the strain rate, the smaller the deformation resistance, and adding 0.3 at.%Y can improve remarkably hot deformability of Ti–43Al–9V and Ti–45Al–5Nb alloys at the same processing parameters. Comparing with the microstructures of Y-free TiAl alloys after deformation, the grain sizes of Y-containing TiAl alloys were much finer and the fraction of the fine equiaxed γ grains formed by dynamic recrystallization increased, and the addition of 0.3 at.%Y decreased the flow stress, the deformation activation energy of Ti–43Al–9V and Ti–45Al–5Nb (numbers indicate at.%) alloys. According to the isothermal hot-compression pressing results, appropriate sets of deformation processing parameters are recommended for the present Y-containing TiAl alloys. These recommended hot deformation processing parameters have been successfully used for the quasi-isothermal canned forging of (0.3%)Y-containing TiAl alloy billets.
Journal: Materials Science and Engineering: A - Volume 499, Issues 1–2, 15 January 2009, Pages 53–57