Thank you so much sir , I am MSc ( Physics ) student and watching this video for my paper (condensed matter ) having topic Lattice defect 🙏 Lots of respect from Ayodhya 🙏💝
Sir which crystal structure has greater strength and hardness- single crystal structure or polycrystalline structure? If polycrystalline structure has greater strength then why turbine blade are preferred to be made single crystalline structure?
At low tempeartures grain boundaries contribute to strength as they impede the dislocation motion. So fine grains having more grain boundaries are preferred. At high tempeartures the grain boundaries actually assist the deformation through grain boundary diffusion and grain boundary sliding. So for high tempearture applications, say turbine blades, coarse grains are better. Single crystals the best.
