Intermetallic Titanium alloys are based on a so called intermetallic phase. From technical interest are TiAl, Ti3Al, Al3Ti and Ti2AlNb. The properties of intermetallics are somehow in between ceramics and metals. They show excellent high temperature properties but less ductility than conventional metals.
Intermetallic Phase TiAl
TiAl shows excellent properties like high temperature strength, oxidation and creep resistance, low density and high fatigue resistance. However TiAl shows a low ductility. This must be considered during component designing and it is the major hurdle for a widespread use for many application. AMT can supply TiAl forgings, billets, plates and sheets. Also complex castings are available because TiAl is used for some high temperature near-net-shape components. TiAl is from interest for applications like jet engine blades, compressor wheels for turbo chargers, automotive valves and other high temperature components. For high temperature application requiring low weight it is a good alternative to Superalloys up to 850°C.
For more detailed information please contact us because there are several TiAl alloys, tailor made for each application.
Intermetallic Phase Ti3Al
Like TiAl, alloys based on the intermetallic phase Ti3Al featuring also high oxidation and creep resistance. The strength levels of tensile and fatigue are much higher than for TiAl. The density is higher than for TiAl alloy, around 4,9g/cm³ but somewhat lower compared to the Ti2AlNb phase. The maximum temperature for long term service is around 750°C. Dependent on the microstructure Ti3Al alloys could show high ductility values up to 20%. New generation Ti3Al alloys like TD-300 show the same oxidation resistance compared to Ti2AlNb alloys.
Ti3Al alloy TD-300 shows excellent strength and ductility. This alloy could be supplied in shapes like billets, plates, sheets and forgings. Current minimum sheet thickness is 0.5 mm. TD-300 is weldable electron beam and Laser welding. TIG welding trials have also been done yet but reduces the ductility. TD-300 can used for long term services up to 700°C. For service times less than 100h it can be used up to 850°C. The fatigue resistance is superior to that of INCONEL-625 up to 800°C. The maximum service temperature depends strongly on the thickness of the oxidation layer.
AMT can supply also forged discs for compressor discs and the manufacturing of BLISKS.
Intermetallic Phase Ti2AlNb
Dependent on the dominant phase Ti2AlNb also referred to as orthorhombic Titanium alloys. Ti2AlNb show also excellent properties like very high strength, high oxidation and creep resistance, ductility and compared to Superalloys, low density. The properties could be tailor made to a wide range of strength levels. For example Ti-22Al-25Nb could be modified from 600-1.600 MPa strength. Compared to many other intermetallic phases Ti2AlNb alloys show high ductility up to 20%. This is very important for many technical application even if the density with 5,3g/cm³ is somewhat higher compared to the 3,8g/cm³ of TiAl alloys. For jet engine parts Ti2AlNb alloys compete with Superalloys for service temperatures up to 800°C. This alloy class is currently under evaluation for jet engine parts with very promising results. Ti2AlNb is also from interest for very high performance automotive application like exhaust systems or valves.
Ti2AlNb alloys are weldable via electron beam or Laser welding. TIG welding has also been tested but reduces the ductility. Parts made of Ti2AlNb could be also shaped by superplastic forming.
Ti-2225 (Ti-22Al-25Nb, at.%)
Ti-2225 is the most developed orthorhombic Titanium alloy. Since 30 Years development the properties were significantly improved. Ti-2225 show strengths of more than 1.300 MPa. Even at temperatures of more than 700°C high fatigue resistance. The oxidation and creep resistance is high up to 800°C. For long term use the maximum service temperature is 700°C. For service times less than 100 hours it could be used up to 900°C. Ti-2225 is available in many shapes like forgings, plates, billets and sheets. Ti-2225 could be used for jet engines and after burner parts. It is also in use as foil material for the processing of SiC continuous fiber reinforced Titanium-Matrix-Composites.
AMT can supply also forged discs for compressor discs and the manufacturing of BLISKS. We can also supply Ti-2225 powder for parts made with Laser-sintering or the Lens® process.
Ti-2224Mo is a further developed variant of Ti-22Al-25Nb alloys. Compared to the Ti-22Al-25Nb alloys, Ti-2224Mo show higher creep and oxidation reistance and slightly less ductility. High strength up to 800°C. Ti2224Mo is available in all shapes like bars, billets, plates and sheets.
AMT can supply also forged discs for compressor discs and the manufacturing of BLISKS. We also supply powder for parts made with Laser-sintering or the Lens® process.