1987 Volume 73 Issue 7 Pages 899-906
The superplastic behaviour (total elongation and strain-rate sensitivity index m) of a powder-consolidated nickel-base superalloy Mod. IN-100 preformed by extrusion under various conditions has been measured at 1 050°C. The results showed that a sample piece extruded with 72% at 1 100°C and annealed at 1 070°C for 1h had the maximum in m at strain rate about 2.0×10-2 s-1.
Subsequently, the sample piece preformed under the condition as mentioned above, packed in 5mm-thick carbon steel (S535C) and heated at 1 100°C was superplastically forged at strain rate about 1.8×10-2 s-1using Inconel 713C dies previously heated at about 600°C. As a result, the sample piece was sound after forged.
Furthermore, the results showed that the heat treatment for grain coarsening after superplastic forging should be performed at the temperature range of 1 200-1 275°C.
