The reactive-sintering process combined with powder-extrusion was developed for #gamma#-TiAl based alloys about ten years ago by Sumitomo Light Metal lad., Ltd. In this paper, the characteristics of the alloys and the reactive sintering process were reviewed. The valve testing results and the production cost were also shown to clarify the possibility of commercial application. These results are summarized as follows:(1)The reactive-sintering process is promising for fabricating the #gamma#-TiAl alloy because of the following reasons : 1) it has balanced mechanical properties and good oxidation resistance, 2) there is a small composition deviation, 3) the pre-sintered materials can be worked easily to make a shape, and 4) characteristic microstructure is fabricated.(2)The engine valves of this alloy can offer the advantages such as better fatigue strength.
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