Materials Science

Министерство науки и высшего образования Российской Федерации 
Южно-Уральский государственный университет 
Политехнический институт 
Кафедра процессов и машин обработки металлов давлением 
 
 
 
 
 
620.22(07) 
Р154 
 
 
 
 
Л.В. Радионова, Ю.Е. Капелюшин 
 
MATERIALS SCIENCE 
 
Учебное пособие 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Челябинск 
Издательский центр ЮУрГУ 
2021 
 

УДК 620.22(075.8) 
Р154 
 
Одобрено  
учебно-методической комиссией 
факультета материаловедения и металлургических технологий  
 
 
Рецензенты: 
заместитель Генерального директора по научной работе  
АО «РусНИТИ», доктор технических наук, профессор А.В. Выдрин; 
директор института элитных программ и открытого образования 
ФГБОУ ВО "Магнитогорский государственный технический 
университет им. Г.И. Носова", доктор технических наук,  
доцент Д.В. Терентьев 
 
 
 
Радионова, Л.В. 
Materials Science: учебное пособие / Л.В. Радионова,  
 
Р154 
Ю.Е. Капелюшин. – Челябинск: Издательский центр ЮУрГУ, 
2021. – 96 c.    
ISBN 978-5-696-05202-1 
В учебном пособии рассмотрены вопросы классификации 
материалов, их основные свойства, принципы выбора и 
использования, 
кристаллизация 
расплавов, 
диаграммы 
состояния, типы структур материалов, фазовые превращения 
в сплавах, механические, физические, технологические и 
эксплуатационные свойства, сплавы системы железо – 
углерод, сплавы цветных металлов, порошковые, композиционные и неметалллические материалы. 
Пособие 
предназначено 
для 
студентов 
технических 
специальностей, изучающих дисциплину «Материаловедение» 
на английском языке.  
 
УДК 620.22(075.8) 
 
 
 
 
ISBN 978-5-696-05202-1 
  © Издательский центр ЮУрГУ, 2021 

 CONTENTS 
FOREWORD............................................................................................. 4 
INTRODUCTION ...................................................................................... 5 
CRYSTALLIZATION ............................................................................... 12 
STRUCTURE OF METAL ALLOYS AND STATE DIAGRAMS 
.............. 19 
STATE DIAGRAM OF ALLOYS WITH UNLIMITED SOLID 
SOLUBILITY OF COMPONENTS .......................................................... 25 
IRON AND IRON BASED ALLOYS. STEEL .......................................... 31 
IRON AND IRON BASED ALLOYS. CAST IRON .................................. 36 
EFFECT OF CARBON AND IMPURITIES ON PROPERTIES 
OF STEELS AND ALLOYS .................................................................... 42 
PHYSICAL, CHEMICAL, MECHANICAL, TECHNOLOGICAL 
AND OPERATIONAL PROPERTIES OF METALS 
................................ 49 
METAL DEFORMATION ........................................................................ 55 
BASICS OF HEAT TREATMENT 
........................................................... 61 
QUENCHING. TEMPERING .................................................................. 66 
THERMOMECHANICAL TREATMENT OF STEEL 
............................... 72 
NON-FERROUS METALS AND ALLOYS 
.............................................. 78 
COMPOSITE MATERIALS WITH A METAL MATRIX ........................... 84 
NON-METALLIC MATERIALS................................................................ 90 
REFERENCES ....................................................................................... 96 
Materials Science 
 3 

FOREWORD 
The presented textbook is lecture notes developed in accordance 
with the State Educational Standard of the Russian Federation and the 
Program for the discipline «Materials Science». 
Since the textbook is written in the form of an abstract of lectures, 
the material is thematically integrated and presented in such volume that 
allows studying it within the two academic hours. The number of lectures 
is designed to study the whole course during one semester. 
In accordance with the academic standards, the following issues are 
considered in the education course: classification of materials, their main 
properties, principles of selection and use, crystallization of melts, state 
diagrams, types and structures of materials, phase transformations in 
alloys, mechanical, physical, technological and operational properties, 
alloys of the iron - carbon system, alloys of non-ferrous metals, powder, 
composite and non-metallic materials. 
The course considers knowledge of students in the disciplines of 
«Chemistry» and «Physics» in the volume studied at technical university. 
The lectures do not contain references to the literature; however, all 
the literature sources that were used by the authors are provided at the 
end of the book. Therefore, if any questions appear, it is needed to use 
the indicated literature. 
The authors hope that this textbook will provide worthy assistance 
during the study. 
 
 
 
 
 
 
 
 
 
4                                                                                                                Materials Science 
 

INTRODUCTION 
Materials science studies the structure and properties of metals, alloys, and other structural materials depending on their composition and 
processing conditions.  
The study of this course will allow an engineer to select materials for 
specific applications during the design and manufacturing of machines 
and devices, also organizing their operation and repair. The information 
on modern methods of obtaining and processing materials, their properties and rational areas of application is needed in order to solve practical 
problems successfully. 
There are two main groups of materials: metals and their alloys and 
non-metallic materials. The metals and alloys are divided into ferrous 
and non-ferrous. The ferrous metals include iron and iron based alloys: 
steel and cast iron. The non-ferrous metals include all other metals: aluminum, copper, titanium, magnesium, lead, tin, nickel, etc. At least 65 
non-ferrous metals are used in modern technology. 
In comparison with all the metals and alloys, steel plays the most 
important role. Steel production accounts for 95% of all metallic materials. The widespread prevalence of steel is due to the fact that it has a 
rare combination of properties. At a comparatively low cost, steel is 
characterized by high strength, ductility and toughness, combined with 
good technological properties. The cost of energy for the production of a 
mass unit of steel parts (their energy intensity) is significantly lower than 
the cost of production of parts from aluminum, titanium and other metals. 
Therefore, steel is widely used in all areas of technology. 
The volume of production of non-ferrous metals and alloys is significantly less, but without their use it would be impossible to develop electrical, radio, instrumentation, aviation, nuclear and space rocket branches of modern technology. 
The non-metallic materials (plastic, rubber, ceramic, glass, glue, 
paint and varnish coatings, wood, fabric, etc.) as structural materials 
serve as an important addition to metals. In some cases non-metallic 
materials are successfully replaced; but sometimes non-metallic materials are indispensable themselves. The engines of internal combustion 
from ceramics that work without water cooling are impossible to manufacture from metal; rocket fairings are made only of non-metallic materials (graphite and ceramics). The shoes and clothes cannot be made of 
metal at all. 
Materials Science                                                                                                                5 
 

The advantage of non-metallic materials is the combination of the 
required level of chemical, physical and mechanical properties with low 
cost and high manufacturability during obtaining the products of complex 
configuration. The complexity in the manufacture of products from nonmetallic materials is 5-6 times lower, and they are 4-5 times cheaper in 
comparison with metals. In this regard, the use of non-metallic materials 
in food, trade and cryogenic technology is constantly increasing. 
Metallurgy is the science that studies the relationship between the 
composition, structure and properties of metals and alloys and the laws 
of their change under thermal, chemical, mechanical, electromagnetic 
and radioactive influences. 
Crystal structure of metals 
All metals and their alloys are crystalline bodies. Metals are called 
chemical elements that are characterized by opacity, gloss, good electrical 
and thermal conductivity, ductility, and also the ability to weld (for many 
metals). It is characteristic of metals that, entering into chemical reactions 
with elements that are non-metals, they give the latter their external, valence electrons. This is explained by the fact that the external electrons of 
metal atoms are loosely bound to its core. Metals have only 1-2 electrons 
on the outer shells, while non-metals have many such electrons (5-8). 
Pure chemical elements (for example, iron, copper, aluminum, etc.) 
can form more complex substances, which may include several metal 
elements, often with an admixture of noticeable amounts of non-metal 
elements. Such substances are called metal alloys. The simple substances that make up the alloy are called alloy components. 
The concept of a crystal lattice is used for the description of the the 
crystal structure of metals. A crystal lattice is an imaginary spatial network where atoms (ions) in the nodes form metal. Particles of matter 
(ions, atoms) from which the crystal is built are located in a specific geometric order, which is periodically repeated in space. The atomiccrystalline structure can be represented by an image not of a series of 
periodically repeating volumes, but of one unit cell. A unit cell is a cell 
that is repeated in all three dimensions. By translating this smallest volume, the crystal structure can be completely reproduced. 
Mostly metals have crystal lattices of the following types (Fig. 1): 
body-centered cube or abbreviated BCC (α-Fe, Cr, W); face-centered 
cube FCC (γ-Fe, Al, Cu); hexagonal close-packed HCP (Mg, Zn, etc.). 
6                                                                                                                Materials Science 
 

 
Fig. 1. Unit cells of crystal lattices: 1 – BCC; 2 – FCC; 3 – HCP 
Some metals at different temperatures can have different crystal lattices. The ability of the metal to exist in various crystalline forms is called 
polymorphism or allotropy. It is customary to designate a polymorphic 
modification, stable at a lower temperature, by the index alpha (α-Fe), 
with the higher beta, then gamma, etc. 
The temperature of transformation of one crystalline modification into another is called the temperature of polymorphic transformation. During polymorphic transformation, the shape and type of the crystal lattice 
change. This phenomenon is called recrystallization. 
In crystalline materials the distances between atoms in different 
crystallographic directions are different. For example, in the bcc lattice in 
the crystallographic plane passing through the face of the cube, there is 
only one atom, since the four atoms at the vertices simultaneously belong to four neighboring unit cells: ¼ · 4 = 1 atom. At the same time, in 
the plane passing through the diagonal of the cube, there will be two atoms:                1+ (¼ · 4) = 2. 
Due to the unequal density of atoms in different directions of the 
crystal, various properties are observed. The dependence of the properties in the crystal on direction is called anisotropy. Anisotropy of properties is characteristic for single crystals, or for the so-called single crystals. Most technical materials, hardened under ordinary conditions, have 
a polycrystalline structure. They consist of a large number of crystals or 
grains. In addition, each individual grain is anisotropic. A different orientation of the individual grains leads to the fact that, in general, the properties of the polycrystalline metal are averaged. 
A polycrystalline body is characterized by quasi-isotropic properties 
- the apparent independence of properties from the direction of testing. 
Materials Science                                                                                                                7 
 

Quasi-isotropy is maintained in the molten state. During pressure treatment (rolling and forging), especially if it is conducted without heating, 
most metal grains acquire approximately the same orientation — the socalled texture, after which the metal becomes anisotropic. The properties 
of the deformed metal along and across the direction of the main deformation can vary significantly. Anisotropy can lead to metal defects – delamination and sheet waviness. Anisotropy must be taken into account 
when designing and developing the technology for the production of 
parts. 
Defects in crystals 
There are always structural defects (imperfections) in the crystals 
due to a violation of the correct arrangement of the atoms of the crystal 
lattice. Defects of the crystalline structure are subdivided according to 
the geometric signs into point, linear and surface. 
Atoms make oscillatory motions near the lattice nodes and with increasing temperature the amplitude of these vibrations increases. Most 
atoms of a given crystal lattice have the same (average) energy and vibrate at specified temperature with the same amplitude. However, individual atoms have energy significantly greater than the average energy 
and move from one place to another. 
Point defects (Fig. 2) are characterized by small dimensions in all 
three dimensions. Their value does not exceed several atomic diameters. Point defects include: a) vacancies - free places in the nodes of the 
crystal lattice; b) interstitial (deployed) atoms - atoms displaced from the 
nodes of the crystal lattice to the interstitial spaces; c, d) impurity atoms 
– atoms of other elements located both in the nodes and in the interstices of the crystal lattice. 
 
 
a   
    
   b 
                     c    
           d 
Fig. 2. Point defects and distortion patterns around them in a crystal     
lattice: a – vacancy; b – Interstitial atom; c, d – Impurity atoms 
8                                                                                                                Materials Science 
 

Linear defects are characterized by small dimensions in two dimensions, but have a significant extent in the third dimension. The most important type of linear defects is edge and screw dislocations (Fig. 3) (in 
the translation from Latin - displacement). Figure 3a shows a diagram of 
the section of the crystal lattice with one “extra” atomic half-plane, i.e. 
edge dislocation. The linear atomic half-plane is called the extra-plane, 
and the lower edge of the extra-plane is called the dislocation line. If the 
extra-plane is located in the upper part of the crystal, then the dislocation 
is called positive and is denoted by a sign  , while in the bottom it is 
negative and denoted by T. The difference between the dislocations is 
often arbitrary. By turning the crystal over, a positive dislocation turns 
into a negative one. The sign of dislocations allows evaluation of the result of their interaction. Dislocations of the same sign repel each other, 
and opposite ones attract. 
 
Fig. 3. Edge (a) and screw (b) dislocations 
Materials Science                                                                                                                9 
 

In addition to the edge dislocations, the screw dislocations in crystals can also form (Fig. 3 b). The crystal is screwed around the dislocation line. A screw dislocation formed by the clockwise rotation is called 
right, and formed counterclockwise – is called left. 
Dislocations are formed during the crystallization of metals, as well 
as during plastic deformation, heat treatment and other processes. 
Surface defects are small in thickness and significant in two other 
dimensions. Usually these are the junctions of the two oriented sections 
of the crystal lattice, i.e. grain boundaries and subgrains. The metals and 
alloys used in the technique are usually polycrystalline bodies, since they 
consist of many separate irregular crystals that are rigidly interconnected. They are commonly called crystallites or grains. The boundaries between the grains are called high-angle, since crystallographic directions 
in neighboring grains form angles reaching tens of degrees. 
Each metal grain consists of individual subgrains forming the socalled substructure. The subgrain is a part of the crystal with respect to 
the correct structure. The subgrain boundaries are dislocation walls that 
divide the grain into separate subgrains or blocks. The subgrains are 
oriented relative to each other from several fractions to the units of degrees - small-angle boundaries (Fig. 4). 
 
Fig. 4. The dislocation structure of the small-angle boundary 
With an increase in the density of dislocations, their movement becomes 
more and more difficult, i.e. the metal is hardened and an increase in the 
applied load is required to continue the deformation. The dislocation 
density is usually understood as the total length   of dislocations per unit 
volume of the crystal  : 
ρ=     
 
 
 
 
(1) 
In addition to the listed defects in the metal, there are three-dimensional 
macro-defects: pores, gas bubbles, non-metallic inclusions, microcracks, 
etc. These defects reduce the strength of the metal. 
10                                                                                                                Materials Science