Nickel base superalloy GH4049 prepared by powder metallurgy

The process of preparing nickel base superalloy, GH4049 from atomized prealloyed powder is studied. The results show that the compacts with relative density over 99% can be made by sintering at 1350 degrees C for 2 h in vacuum. Sintering in vacuum is better than that in argon atmosphere. The sintering way is super-soliclus liquid phase sintering. The tensile strength and yield strength and ductility are about 1113 MPa and 760 MPa and 13% respectively. They are near the wrought superalloy GH4049. There are two kinds of gamma' phase precipitated in the grains. The rectangular gamma' phase is about 200 nm and the global gamma' phase is about 40 nm. The average grain size is below 80 mu m. Its property of the compression stress relaxation at 850 degrees C is better than wrought cobalt base superalloy GH605 (L-605). The results lay the foundation of near-net-shape forming for the powder nickel superalloy GH4049. (C) 2008 Elsevier B.V. All rights reserved.