Faculty of Engineering and
Architecture
Mechanical Engineering Department
Mech636-2007
MECH636: Modeling Solidification Processes
Syllabus
INSTRUCTOR
Dr. Marwan Darwish, Mech.Eng.,
Room 324, ext. 3590.
Email: darwish@aub.edu.lb
CATALOG DESCRIPTION:
The course seeks to impart a coherent view of solidification processes and how they are modeled. Topics for
the first part of the course will include: homogeneous and heterogeneous nucleation, with plane front, cellular
and dendritic pattern, columnar and equiaxed grain growth. Phenomena affecting the quality of castings such
as micro-segregation, constituent under-cooling, macro-segregation and porosity formation will also be
covered. In the second part solidification models will be developed and applied in the context of casting
operations.
Content:
Heat flow in solidification processes; Thermodynamics of solidification: Nucleation and Growth; Binary
Phase Diagrams, Phase diagram Computation; Microstructure evolution, Constitutional under-cooling;
Columnar and Equiaxed Solidification
Enthalpy method; Mushy zone modeling; Phase-field method; Volume-Averaging of Conservation equations;
Multi-scale models; Modeling Solidification defects.
TEXTBOOK
The material covered will rely on class notes. Some of the seminal papers in the modeling and development
of microstructure will be assigned for in-depth study and later presentation to the class.
REFERENCES
Two books will be used as references in addition to a number of Journal articles
Solidification processing M. Flemings, McGraw-Hill, 1974
Fundamentals of Solidification, Trans. Tech. Publications, Switzerland, 1992
OBJECTIVES
(Correlate to ME program objectives 1, 2, and 6)
1. To provide students with a coherent knowledge of the microstructures forming during the solidification
of metals
2. To enable students to model solidification processes at the microscopic and macroscopic scales while
understanding the inherent limitations of different models
3. To enable the students to apply their knowledge to the simulation of metal casting operations to improve
mould design and minimize casting defects.
LEARNING OUTCOMES:
Outcome 1 (Correlated to Course Objective 1):
Student will be able to describe the types of microstructure present in a casting given a material and a heat
transfer rate
Outcome 2 (Correlated to Course Objective 1):
Student will be able to determine the effects of heat transfer, temperature on the development of
microstructures within a cast
Outcome 3 (Correlated to Course Objective 2):
Students will be able to solve and interpret solidification problem using Fluent.
Outcome 4 (Correlated to Course Objective 2):
Students will be able to write a program to that implements a variety solidification models
Outcome 5 (Correlated to Course Objective 3):
Students will be able to use visualization techniques to present and interpret the numerical solution.
Outcome 6 (Correlated to Course Objective 3):
Students will be able to predicts some casting defects based on a numerical solution .
RESOURCES AVAILABLE TO STUDENTS:
Class handouts and presentations will be posted on Moodle
COURSE OUTLINE:
Solidification Physics
1.
Phase Transformation in Metals and Alloys (1 weeks)
a. Gibb’s Free Energy
b. The Driving force for solidification
c. Binary Solutions
d. Review of Phase Diagram
2.
Solidification (2 weeks)
a. Nucleation in Pure Metals
b. Growth of a pure solid
c. Alloy Solidification
d. Solidification of Ingots and Castings
e. Application: Triangle, Matlab
3.
Solidification Microstructure (3 weeks)
a. Constraned and unconstrained growth
b. Morphology of dendrites
c. Dendrite growth
d. Primary and Secondary Spacing of dendrites
e. Regular and Irregular eutectics
f. Diffusion coupled growth
g. Operating range of eutectics
h. Competitive growth of dendritic and eithecti phases
4.
Solute Redistribution (1 weeks)
a. Mass-balance in directional solidification
b. Message Passing Interface
c. Microsegragation
Solidification Modeling
1.
Diffusion Equation (1 weeks)
a. Geometric Discretization
b. Equation Discretization
c. Diffusion in a Square Domain
2.
Enthalpy Method (2 weeks)
a. Deriving the equation
b. Algorithm for Enthalpy Method
c. Heat Capacity-Approach
d. Solving a diffusion problem
3.
Macro/Microscopic Two phase models (2 weeks)
a. Volume Averaging
b. The Volume Averaged Two-Phase Model
c. Modeling microstructure with two phase models
d. Microstructure modeling with phase-field method
4.
Phase-Field Methods (2 weeks)
5.
Project Presentations (1 week )
ASSESSMENT AND EVALUATION
The course grade will be a composite of several measures, including class participation (in-class exercises,
presentations of reading material), examination and a research component
Assignments
Exams I and II
Research project
25%
30%
45%
ACADEMIC INTEGRITY:
The AUB catalog defines various forms of academic dishonesty and procedures for responding to them. All
forms are violations of the trust between students and teachers. Students should familiarize themselves with
the penalties for plagarism and other forms of cheating.
COURSE POLICIES:
Students are encouraged to attend all classes. In case of absence from any class, students are required to
cover the missed material and inquire about any announcements made during their absence. Students who
miss more than one fifth of class sessions are liable to be dropped from the course.
No exam make-ups will be given. If the reason for missing the exam is deemed acceptable the grades
percentage of the missed exam will be distributed amongst the other course graded activities
Each student is expected to read the assignment material and submit assignment on due dates
Late assignments will not be accepted