材料科学基础双语课件
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2材料科学基础英文版课件_
• Introduction, experiment, results and discussion, summary
– Effect of phosphorus grain boundary segregation on intergranular fracture
• Introduction, experiment, results and discussion, summary
2 Ceq Cg
erfc(x) = 1 – erf(x)
2019/10/7
(McLean, 1957)
Equilibrium grain boundary segregation (3)
Thermal equilibrium concentration
Solute boundary concentration
Temperature
Experiment (3)
(Austenization) (Normalization)
980℃×30min 920℃×50min
(Termper)
650℃×2h
(Ageing)
560℃ 520℃
480℃
(Aging under different stresses for different time)
(Seah, 1977)
Equilibrium grain boundary segregation (2)
Segregation kinetics
C C etq C C 0 0 1exp 4 2 2 D dt2 erfc
4D t
2 2d2
2019/10/7
Ageing time
Outline
– Effect of phosphorus grain boundary segregation on intergranular fracture
• Introduction, experiment, results and discussion, summary
2 Ceq Cg
erfc(x) = 1 – erf(x)
2019/10/7
(McLean, 1957)
Equilibrium grain boundary segregation (3)
Thermal equilibrium concentration
Solute boundary concentration
Temperature
Experiment (3)
(Austenization) (Normalization)
980℃×30min 920℃×50min
(Termper)
650℃×2h
(Ageing)
560℃ 520℃
480℃
(Aging under different stresses for different time)
(Seah, 1977)
Equilibrium grain boundary segregation (2)
Segregation kinetics
C C etq C C 0 0 1exp 4 2 2 D dt2 erfc
4D t
2 2d2
2019/10/7
Ageing time
Outline
skja_03 Fundamentals of Crystallography 材料科学基础(英文课件)
2020/7/3
Seven Crystal Systems
Triclinic
Monoclinic
Orthorhombic Tetragonal Cubic Hexagonal Rhombohedral
a≠b≠c ，α≠β≠γ≠90° a≠b≠c ， α＝β＝90°≠γ
α＝γ＝90°≠β a≠b≠c ，α＝β＝γ＝90° a＝b≠c ，α＝β＝γ＝90° a＝b＝c ，α＝β＝γ＝90° a＝b≠c ，α＝β＝90°γ＝120°
5. Draw a primitive cell for BCC lattice.
Thank you !
3
2020/7/3
We identify 14 types of unit cells, or Bravais lattices, grouped in seven crystal systems.
2020/7/3
Ⅰ.Seven crystal systems
All possible structure reduce to a small number of basic unit cell geometries. ① There are only seven, unique unit cell shapes that can be stacked together to fill three-dimensional. ② We must consider how atoms can be stacked together within a given unit cell.
120o
120o 120o
c
a ba
2020/7/3
Examples and Discussions
Seven Crystal Systems
Triclinic
Monoclinic
Orthorhombic Tetragonal Cubic Hexagonal Rhombohedral
a≠b≠c ，α≠β≠γ≠90° a≠b≠c ， α＝β＝90°≠γ
α＝γ＝90°≠β a≠b≠c ，α＝β＝γ＝90° a＝b≠c ，α＝β＝γ＝90° a＝b＝c ，α＝β＝γ＝90° a＝b≠c ，α＝β＝90°γ＝120°
5. Draw a primitive cell for BCC lattice.
Thank you !
3
2020/7/3
We identify 14 types of unit cells, or Bravais lattices, grouped in seven crystal systems.
2020/7/3
Ⅰ.Seven crystal systems
All possible structure reduce to a small number of basic unit cell geometries. ① There are only seven, unique unit cell shapes that can be stacked together to fill three-dimensional. ② We must consider how atoms can be stacked together within a given unit cell.
120o
120o 120o
c
a ba
2020/7/3
Examples and Discussions
2材料科学基础英文版课件_(12)
• Deformation-induced nonequilibrium vacancies
Point Defects – Point Defects in Metals (4)
The molar free energy of the crystal containing Xv mole of vacancies:
பைடு நூலகம்• There is always some level of impurity or foreign atoms in a metal, leading to the formation of an alloy
• Alloys – solid solutions and intermetallics • Concept: solvent – the matrix or host; solute
• Thermal equilibrium vacancies and interstitials
• Quenching-induced nonequilibrium vacancies and interstitials
• Irradiation-induced nonequilibrium vacancies and interrstitials
Point Defects – Point Defects in Metals (1)
1. Vacancies and Interstitials (self-interstitials)
Frenkel pair: vacancy + interstitial
Schottky defect: moving an atom to the surface produces a vacancy
Point Defects – Point Defects in Metals (4)
The molar free energy of the crystal containing Xv mole of vacancies:
பைடு நூலகம்• There is always some level of impurity or foreign atoms in a metal, leading to the formation of an alloy
• Alloys – solid solutions and intermetallics • Concept: solvent – the matrix or host; solute
• Thermal equilibrium vacancies and interstitials
• Quenching-induced nonequilibrium vacancies and interstitials
• Irradiation-induced nonequilibrium vacancies and interrstitials
Point Defects – Point Defects in Metals (1)
1. Vacancies and Interstitials (self-interstitials)
Frenkel pair: vacancy + interstitial
Schottky defect: moving an atom to the surface produces a vacancy
材料科学基础英文版课件（ＰＤＦ）
Law • Steady State: the concentration profile doesn't
change with time.
Steady State:
J x(left)
J x(right) J x(left) = J x(right)
x
Concentration, C, in the box doesn’t change w/time.
Non Steady State Diffusion
• Concentration profile,
dx
C(x), changes with time. J (left)
J (right)
• To conserve matter:
J (right)
− J (left)
=
dC −
dx
dt
dJ = − dC
ΔJ y
=
− ∂J y ∂y
dxdydzδt
ΔJ z
= − ∂J z ∂z
dxdydzδt
对整个元体积：
−
⎜⎜⎝⎛
∂J x ∂x
+
∂J y ∂y
+
∂J z ∂z
⎟⎟⎠⎞dxdydzδt
若 δt 时间内粒子浓度变化δc ，则在dxdydz
元体积中粒子变化为
δcdxdydz
∴ ∂c ∂t
=
−⎜⎜⎝⎛
∂J x ∂x
Fick’s Second Law
δt 时间内沿x方向扩散
元体积dxdydz
流入的粒子数： J x dydzδt
流出的粒子数：
(J x
+
∂J x ∂x
dx)dydzδt
skja_06CrystallographicFormulas材料科学基础英文课件
(u1a)2 (v1b)2 (w1c)2 (u2a)2 (v2b)2 (w2c)2
For hexagonal: cos
u1u2
v1v2
w1w2
(
c a
)2
1 2
(u1v2
u2v1)
u12
v12
w12
(
c a
)2
u1v1
u22
v22
w22
(
c a
)2
u2v2
10. The volume of unit cells V
材料科学基础
Fundamental of Materials
Prof: Tian Min Bo
Tel: 62795426 ，62772851 E-mail: tmb@ Department of Material Science and Engineering Tsinghua University. Beijing 100084
For hexagonal crystals:
1 d2
4 3
h2
hk a2
k2
l2 c2
7. The length of [u v w]
L[uvw] (ua )2 (vb )2 (wc )2 2vwbccos 2uwac cos 2uvabcos
For cubic: L[uvw] a u2 v2 w2
For simple cubic (001) aaaa…… (110) abab……
shift 1 [1 10], along [1 10] 2
This sequence is called the stacking order
Ⅱ.Comparison of stacking mode of HCP and FCC
材料科学基础英文版课件-(13)
Ductility
The ability of a material to be stretched without breaking.
Toughness
The ability of a material to absorb energy before fracturing.
Physical Properties
Some common examples of polymers include plastic, rubber, and fiberglass.
Polymers can be natural or synthetic.
Composites
Composites are materials that consist of two or more materials with different physical and chemical properties.
Nondestructive testing techniques: 超声波检测，射线检测，涡流检测等 。
02
Materials Properties
Mechanical Properties
Elasticity
The ability of a material to return to its original shape after being deformed by an external force.
Metals
Metals are materials that are typically ductile, malleable, and conduct electricity well.
They are often used in the manufacturing of various
材料科学基础英文版课件_(11)
d
e
g
f
7c/8
(2/3,1/3,3/4)
dae a
Ro = a2/2 – R
= 2R – R =
g
f
0.414R (a=2R)
(2/3,1/3,7/8)
Rt = (3/8)c – R = (3/8)x1.633a –R = 0.225R (a=2R)
Metallic crystal structures (11)
Metallic crystal structures (7)
3) Hexagonal close-packed (HCP) crystal structure
Each unit cell contains 6 atoms (12(1/6) + 2(1/2) + 3 = 6)
2R = a R = a/2
Two other features: coordination number (CN) and atomic packing factor (APF) CN: the number of nearest-neighbour atoms – 12 for FCC APF: the fraction of atom-occupied volume in a unit cell
4.2198 10-22 g Unit cell volume = a3 = (0.36148)3 = 0.04723 nm3 = 4.7234 10-23 cm3 = (weight of atoms in each unit cell)/unit cell voulme = 4.2198 10-22
CN = 12 c/a = ? APF = ?
Equilateral triangle
2材料科学基础英文版课件_(9)
T1 T4 due to both
Intergranular fracture stress (Small segregation)
Cleavage fracture stress
Stress
Intergranular fracture stress (Large segregation)
TIC
T1 T2 T3
Impact Fracture Testing
Impact Fracture Testing (1)
When a material is subjected to a sudden, intense loading (e.g. impact), it often behaves in a more brittle manner than observed in the tensile test. Tensile testing: the load is applied slowly Impact testing: the full load is applied very rapidly
Impact Fracture Testing (6)
FCC materials (e.g. austenitic stainless steels, Cu, Ni, and Al alloys): there is no ductile-to-brittle transition
BCC materials (e.g. ferritic steels, Cr and Mo alloys) and HCP materials (Mg alloys): there is ductile-to-brittle transition
Ductile-to-brittle transition temperature (DBTT) as a function of ageing time at 540 ◦C (error bars represent the S.D.)
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control the material properties (for example by altering the
grain structure, or the presence of defects in the atom
packing) or to fabricate the material into the desired shape.
extra material, joining parts (e.g., by soldering or welding),
forming (forging, rolling, bending, etc.), or compacting particles which are then fused together (sintering, used for
gases (and most engineering materials are used in solid
form).
1.1 What is Materials Science and Engineering?
It may seem abstract and remote from real engineering to
The Science and Engineering of Materials
Aim
English atmosphere: speaking, reading, writing and lisห้องสมุดไป่ตู้ening; Specialty vocabulary; Specialty knowledge;
form. As this mixture solidifies, different structures form as a function of temperature. The phase diagrams that provide
a road map to these structures are a second necessary tool
materials
1.1 What is Materials Science and Engineering?
For most of mankind's history, the available materials were few and essentially natural such as clay for bricks and pottery, wood and stone for tools and construction,
1.1 What is Materials Science and Engineering?
For many real materials, the formation of the
microstructure begins with some combination of elements
or mixing together of the proper components, often in liquid
define and limit the capabilities that the device or
structure can have, and the techniques that can be used
to fabricate it.
1.1 What is Materials Science and Engineering?
Chapter 1 - Introduction
Outline
1.1 What is Materials Science and Engineering? 1.2 Classification of Materials 1.3 Functional Classification of Materials 1.4 Classification of Materials Based on Structure 1.5 Environmental and Other Effects
1.1 What is Materials Science and Engineering?
It is common in courses such as this one to start at the
smallest scale, that of the atoms. Some familiarity with
Materials science and engineering (MSE) is an
interdisciplinary field concerned with inventing new
materials and improving previously known materials by
start at the atomic level and then gradually work up through
the ways that atoms pack together (and the important
defects in these packings) to larger dimensions, but this approach provides the necessary tools to understand and deal with the later topics.
1.6 Materials Design and Selection
Objectives
Introduce the field of materials science and
engineering (MSE)
Provide introduction to the classification of
atoms and the bonds that form between them should be
retained from chemistry courses, but perhaps not much of that has dealt with solids, as compared to liquids and
the Iron Age, and so forth.
1.1 What is Materials Science and Engineering?
Materials Science and Engineering forms the bedrock
for the engineering disciplines because the structures, components, and devices that engineers design and use must be made out of something, and that is a material. The properties of the materials that are available
1.1 What is Materials Science and Engineering?
Microstructure includes structure at dimensions ranging
from the atoms in the material and the order (or lack of it) of
their arrangement, up to the tiny grains of individual crystals
that pack together to form most solids, and even up to the nearly macroscopic level of fibers in paper, sand in concrete, and the thin, multiple layers of plastic, metal, and paper in a microwave popcorn bag.
natural fibers (either from plants or animal hair) for
cords and textiles, and skins for containers and clothing.
The ability to modify natural materials, extract useful
developing a deeper understanding of the microstructurecomposition-synthesis-processing relationships.
1.1 What is Materials Science and Engineering?
Structure means a description of the arrangements of
Anthropologists study the material artifacts of past
civilizations to understand how they were fabricated, and in
turn, to gain insight into the level of technology and sophistication of the culture. The role of materials in the advance of civilization and culture is powerfully summarized by the fact that it is the name of each dominant new material that has been used to describe the culture - the Stone Age, the Bronze Age,
grain structure, or the presence of defects in the atom
packing) or to fabricate the material into the desired shape.
extra material, joining parts (e.g., by soldering or welding),
forming (forging, rolling, bending, etc.), or compacting particles which are then fused together (sintering, used for
gases (and most engineering materials are used in solid
form).
1.1 What is Materials Science and Engineering?
It may seem abstract and remote from real engineering to
The Science and Engineering of Materials
Aim
English atmosphere: speaking, reading, writing and lisห้องสมุดไป่ตู้ening; Specialty vocabulary; Specialty knowledge;
form. As this mixture solidifies, different structures form as a function of temperature. The phase diagrams that provide
a road map to these structures are a second necessary tool
materials
1.1 What is Materials Science and Engineering?
For most of mankind's history, the available materials were few and essentially natural such as clay for bricks and pottery, wood and stone for tools and construction,
1.1 What is Materials Science and Engineering?
For many real materials, the formation of the
microstructure begins with some combination of elements
or mixing together of the proper components, often in liquid
define and limit the capabilities that the device or
structure can have, and the techniques that can be used
to fabricate it.
1.1 What is Materials Science and Engineering?
Chapter 1 - Introduction
Outline
1.1 What is Materials Science and Engineering? 1.2 Classification of Materials 1.3 Functional Classification of Materials 1.4 Classification of Materials Based on Structure 1.5 Environmental and Other Effects
1.1 What is Materials Science and Engineering?
It is common in courses such as this one to start at the
smallest scale, that of the atoms. Some familiarity with
Materials science and engineering (MSE) is an
interdisciplinary field concerned with inventing new
materials and improving previously known materials by
start at the atomic level and then gradually work up through
the ways that atoms pack together (and the important
defects in these packings) to larger dimensions, but this approach provides the necessary tools to understand and deal with the later topics.
1.6 Materials Design and Selection
Objectives
Introduce the field of materials science and
engineering (MSE)
Provide introduction to the classification of
atoms and the bonds that form between them should be
retained from chemistry courses, but perhaps not much of that has dealt with solids, as compared to liquids and
the Iron Age, and so forth.
1.1 What is Materials Science and Engineering?
Materials Science and Engineering forms the bedrock
for the engineering disciplines because the structures, components, and devices that engineers design and use must be made out of something, and that is a material. The properties of the materials that are available
1.1 What is Materials Science and Engineering?
Microstructure includes structure at dimensions ranging
from the atoms in the material and the order (or lack of it) of
their arrangement, up to the tiny grains of individual crystals
that pack together to form most solids, and even up to the nearly macroscopic level of fibers in paper, sand in concrete, and the thin, multiple layers of plastic, metal, and paper in a microwave popcorn bag.
natural fibers (either from plants or animal hair) for
cords and textiles, and skins for containers and clothing.
The ability to modify natural materials, extract useful
developing a deeper understanding of the microstructurecomposition-synthesis-processing relationships.
1.1 What is Materials Science and Engineering?
Structure means a description of the arrangements of
Anthropologists study the material artifacts of past
civilizations to understand how they were fabricated, and in
turn, to gain insight into the level of technology and sophistication of the culture. The role of materials in the advance of civilization and culture is powerfully summarized by the fact that it is the name of each dominant new material that has been used to describe the culture - the Stone Age, the Bronze Age,