(66c) Initial Steps Toward Coarse-Grained Metal Segregation during the Solidification of Ti-Al- V Alloys | AIChE

(66c) Initial Steps Toward Coarse-Grained Metal Segregation during the Solidification of Ti-Al- V Alloys

Authors 

Mainardi, D. S., Louisiana Tech University
Initial Steps Toward Coarse-Grained Metal Segregation During the Solidification of Ti-Al-V Alloys

Authors: Jwala Parajuli1, and Dr. Daniela S. Mainardi2

1Institute for Micro-manufacturing, Louisiana Tech University

2Institute for Micro-manufacturing, Chemical Engineering, Louisiana Tech University

3D metal printing is widely researched as a cheaper and efficient alternative for current prototyping methods. The process however has many challenges that needs to be overcome before it can cross the barrier of being unadoptable widely. Availability of compatible raw materials and the quality of the printed product are two of the significant challenges. To better study the quality (strength and defects) of the printed product it is important to study the thermodynamics during phase change.

A coarse-grained approach is being developed in the Mainardi Group at Louisiana Tech University to shed light on the solidification process during 3D metal printing process. Finding the global minimum serves as an initial step towards studying the solidification process of metal alloys. In the liquid phase (non-periodic), the global minimum determines the geometric ground state configuration of atoms comprising the system, while for a periodic system it gives the crystalline ground state structure of the solid. In any case, finding the global minimum (ground state structure) of large systems is computationally very expensive because the number of local minima increases exponentially with respect to the number of atoms in the system.

For our study we consider Ti6Al4V powder as the raw material for the process. A test was run using a python code to find the global minimum structure of Ti-Al and Ti-Al-V alloys using the Minima Hopping Method combined with Molecular Dynamics. Nanoclusters with 1000 atoms for four different compositions of Ti-Al (Ti360Al640, Ti432Al568, Ti458Al542, Ti510Al503), and one composition of Ti-Al-V (Ti904Al56V40) were modeled investigated. The Atomic Simulation Environment in Python was used for the simulations. Morse potential and Zope-Mishin interatomic potential for Ti-Al combination were explored to describe interatomic interaction in these simulations. Qualitatively, metal segregation can be observed as time evolves dictating the structural and mechanical properties the final printed product will have.