Energija meje rotiranih zrn v modelu faznega polja kristala

Iglar, Boštjan (author), Kugler, Goran (mentor), Berčič, Matjaž (co-mentor)

Osrednji cilj študija inženirskih materialov je razumeti in določiti povezave med strukturo in lastnostmi materialov. V polikristalnih materialih so mnoge lastnosti odvisne od mej med različno orientiranimi kristalnimi zrni. V tej diplomski nalogi sem se ukvarjal z računalniško simulacijo rasti vstavljenega zrna po PFC metodi. Spremljal sem kako se spreminjata prosta in površinska energija simulirane površine v odvisnosti od rotacije zrna v matrici. Vzporedno sem spremljal tudi nastajanje dislokacij, tako število kot tudi njihovo razporeditev. Simulacije sem delal na dveh različnih začetnih polmerih zrn. Ugotovil sem, da je število dislokacij premo sorazmerno z rotacijo zrna, prav tako tudi prosta energija. Po drugi strani pa površinska energija simulirane površine narašča z rotacijo zrna, vendar je le ta večja pri manjšem polmeru zrna.

• Language: Slovenian
• Keywords: metoda PFC, geometrijsko potrebne dislokacije, površinska energija, mikrostruktura, orientacije zrn, atomistične simulacije
• Work type: Bachelor thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2018
• PID: 20.500.12556/RUL-101742
• COBISS.SI-ID: 1739615
• Publication date in RUL: 01.07.2018

Secondary language

• Language: English
• Title: Grain boundary energy in Phase-Field Crystal model

Abstract

In Materials engineering the main goal is to understand and define connections between structure and properties of materials. In polycrystalline materials many of the material's attributes depend on the border between different orientated crystal grains. In this diploma work, I made several computer simulations. I simulated growth of the embedded grains using the PFC method. I observed the changing of the free energy and the surface energy of the simulated surface in co-dependance with the rotation of the grain in the matrix. In the same time I observed the creation of dislocations, the numbers of them and their positioning. I did simulations on two different grain radius. I determined that the number of dislocations is proportional to the rotation of the grain. On the other hand, the surface energy of the simulated surface increased with the rotation of the grain, and was larger when a smaller grain radius was used.

• Keywords: PFC method, geometrically necessary dislocations, surface energy, microstructure, grain orientations, atomistic simulations