TOKYO INSTITUTE OF TECHNOLOGY

Course description and aims

Properties and functions of metals and alloys as crystalline materials are characterized by their crystal structure in a nano scale of atomic size, and by their microstructure including lattice defects, grain boundaries, and phase interfaces in a micro-to-macro scale. Therefore, it is quite important to understand how to control microstructure based on the knowledge of the formation mechanism. For instance, mechanical properties, such as strength and ductility, of structural materials and physical properties, such as electrical and thermal conductivity, of functional materials are originated form crystal structure, phase constitution, and microstructure. This course covers the following topics as focusing on solidification processes through which the various morphologies of microstructure are firstly formed in the fabrication process of a material. Topics included: thermodynamics understanding of solidification as the phase transformation from liquid to solid phases, the condition of nucleation in a molten metals and alloys which is based on the classical theory of homogeneous nucleation and heterogeneous nucleation, features of crystal growth at the solid-liquid interface from the view point of atomic shuffles and heat flows, microstructure development of conventional casting, crystallographically preferred crystal growth and alignment control of microstructure according to the unidirectional solidification method, and so forth. Moreover, microstructure formation through typical invariant reactions in binary alloy phase diagrams, i.e., eutectic reaction and peritectic reaction, is important to learn in this course.

Student learning outcomes

This course is designed for students to learn and to acquire the ability to explain the followings.
１） Phase transformation from liquid to solid based on thermodynamics.
２） Homogeneous nucleation and heterogeneous nucleation based on the classical theory of nucleation and growth.
３） Atomic diffusion and shuffle at the solid-liquid interface, energetically stable morphology of grown crystals, and the relationship between supercooling and growth rate.
４） Variations in solidification microstructure of cast alloys and formation mechanism of dendrites being affected by heat flow and thermal conduction.
５） Stability of solid-liquid interface affected by the compositional supercooling during the crystal growth from molten alloys,
６） Partitioning and redistribution of solute elements in the case of equilibrium and non-equilibrium solidification.
７） Microstructure formation process according to the eutectic reaction and peritectic reaction in binary alloy systems together with phase diagrams.

Keywords

Solidification, Classical theory of Nucleation and Growth, Crystal growth, Solid-liquid interface, Supercooling, Compositional supercooling, Dendrite, Unidirectional solidification, Equilibrium redistribution coefficient of solute elements, Microstructure control, Phase diagram, Invariant reaction, Phase equilibrium

Competencies that will be developed

Class flow

Lecture handouts are used in the class and exercise problems are assigned to students at the beginning of each class. Note that an exercise problem may be done within a class or be assigned as a homework. Students should read the course schedule to check topics covered on that day, and preparation and review are required.

Course schedule/Required learning

Out-of-Class Study Time (Preparation and Review)

To enhance effective learning, students are encouraged to spend approximately 100 minutes preparing for class and another 100 minutes reviewing class content afterwards (including assignments) for each class.
They should do so by referring to textbooks and other course material.

Textbook(s)

Handouts for every class (PDF or printed )

Reference books, course materials, etc.

Nishizawa, Taiji. Thermodynamics of Microstructure (Mikurososhiki-no-Netsurikigaku). Sendai: The Japan Institute of Metals and Materials; ISBN-13: 978-4889030280. (Japanese)，Nishizawa, Taiji. Tamura, Imao. Sudo, Hajime. Metallography (Kinzokusoshikigaku). Tokyo: MARUZEN Co.,Ltd.; ISBN-13: 978-4621082430, (Japanese).

Assessment criteria and methods

Students' knowledge of comprehension of solidification thermodynamics as phase transformation, homogeneous and heterogeneous nucleation, effects of atomic shuffles and heat flow on the crystal growth, Crystal growth from molten alloys, solidification microstructure development process according to binary invariant reactions will be assessed. Final exams (60%) and exercise problems (40%). The final exam and at least 2/3 attendance of exercise problems are necessary to take the credits, regardless of total scores. Credits require 60 scores and higher out of 100.

Related courses

• Crystal Growth and Microstructure B
• Phase Diagram and Stability in Metals
• Thermodynamics of Materials
• Crystallography
• Science and Engineering of Ferrous Materials I
• Science and Engineering of Ferrous Materials II
• Science and Engineering of Non-ferrous Materials

Prerequisites (i.e., required knowledge, skills, courses, etc.)

Not applied.

Contact information (e-mail and phone)    Notice : Please replace from "[at]" to "@"(half-width character).

Yoshisato Kimura: kimura.y.ac[at]m.titech.ac.jp, 045-924-5157

Office hours

Will be noticed on the first day of the lecture. It is basically recommended to contact by e-mail or telephone in advance to schedule an appointment.