Nickel based-superalloys are used in applications requiring strength at high temperatures. Most of these alloys are precipitation hardened by a γ'[(Al,Ti)] phase coherently precipitated in a fcc matrix. The properties and resistance to microestructural changes at high temperatures depend on factors such as particle size, coarsening rate, distribution and volume fraction of the γ precipitate, factors that can be modified through different heat treatments. The present work describes the effect of heat treatments to produce different γ'[(Al,Ti)] precipitate sizes and distribution in a CMSX-2 superalloy. Using subsequent aging treatment at constant temperature, we studied de evolution and growth of such precipitate particles and determined the activation energy for coarsening.
Nickel alloys; high temperature; particle growth; kinetics
