| Intermetallic compound TiAl has good mechanical properties at high temperatures but it is brittle at room temperature. On the other hand the Ti-10V-2Al-3Fe alloy(Ti-10-2-3), one of β-Ti alloys, has high strength and toughness at room temperature. The purpose of this work was to manufacture composite materials having only merits of both TiAl and Ti-10-2-3, and to investigate the mechanical properties of the composite materials at high temperatures. TiAl and Ti-10-2-3 powders were prepared by mechanical alloying. The mixed powders of TiAl and Ti-10-2-3 were consolidated by pseudo-HIP. The high density could not be obtained in composite materials by this method as TiAl particles constrained the flow of Ti-10-2-3 particles during consolidation. The reaction layer(Ti₃Al) about 5 ㎛ thick was formed between TiAl and Ti-10-2-3, and the interface between the layer and TiAl, and/or between the layer and Ti-10-2-3 was the path of crack propagation. The UTS of TiAl/Ti-10-2-3(40:60 vol. ratio) composite material was found to be higher than that of typical Ti-6V-4Al alloy at 815℃, while it was lower at 600℃. |
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