Density functional theory (nanoscale)
The images below show formation energies and lattice parameters of nitrides, carbides and Z phase. They also show substitutional atoms, vacancies and interstitials as well as intermediate configurations between nitride, Z phase and diffusion.
B1 lattice of nitride
Bh lattice of nitride
tetragonal Z phase
Particle growth in a creep resistant, rigid matrix (K = 0, red curve), in an easily deformable matrix (K = 0, blue curve) and for intermediate cases, depending on the accommodation mechanism the particle growth rate differs by more than three orders of magnitude.
Thermodynamic-kinetic models
Z-phase particles form by diffusion of Cr into the precursory nitrides. The resulting volume misfit requires some accommodation process.
The Z-Ultra project is funded by FP7 under NMP.2012.2.2-3 - Advanced materials for high-temperature power generation call with Grant agreement no: 309916.
Fraunhofer Institute for Mechanics of Materials IWM
