Creep Properties Dependence to Solution Heat Treatment of Second and Third Generation Ni-Based Single Crystal Superalloys

Computational designComputational design is increasingly being used by industry and research institutes for the development of new compositions of Ni-based single crystalSingle crystal (SX) superalloysSuperalloys. Alloy selection is often based on the mechanical propertiesMechanical properties of the fully heat-treated Ni-based SX superalloysNi-based SX superalloy. However, a more complex chemical composition leads to a more complex solution heat treatmentSolution heat treatment (ST). The development of a ST to reach optimum homogenization, requires time and resources, overall penalizing the time/cost savings provided by computational designComputational design approaches. Thus, the present study investigates several superalloysSuperalloys “as cast” mechanical propertiesMechanical properties to predict the creepCreep life of the solution heat treated alloy. Four commercial superalloysSuperalloys with distinct chemical composition were chosen. Each alloy was investigated in (i) the as cast (AC) and (ii) solution treated and aged (ST) states. The superalloysSuperalloys were creepCreep tested at 950 °C/390 MPa and 1050 °C/190 MPa. A creep life improvementCreep life improvement by a factor of 1.5–3 times has been observed after the ST, irrespective of the alloy chemical composition or creepCreep test conditions. Down-selecting alloys’ composition from the as-cast creep propertiesCreep properties can be a viable approach to speed-up alloy designAlloy design.