Authors

  • Khasanov Abdurashid Solievich
    Professor, Dr. Sci., Almalyk BranchNational University of Science and Technology "MISIS", Almalyk, Uzbekistan
  • Utkir Mirzakamolovich Khalikulov
    Associate Professor, Almalyk Branch National University of Science and Technology "MISIS", Almalyk, Uzbekistan
  • Djeparova Medine Narimanovna
    Student Almalyk Branch National University of Science and Technology "MISIS", Almalyk, Uzbekistan

DOI:

https://doi.org/10.37547/tajas/Volume07Issue03-04

Keywords:

Modification crystallization nanoparticles

Abstract

This article examines current approaches to modification and crystallization, as well as their practical applications in the field of materials science. An analysis of key modification tasks is provided, including the management of material structures, enhancement of their mechanical and chemical properties, and optimization of thermal and electrical characteristics.

An overview of contemporary research dedicated to steel crystallization processes is presented, with an emphasis on the use of rare earth elements, nanoparticles, and computer modeling methods. Experimental techniques for studying crystallization and modification processes, such as X-ray diffraction, scanning electron microscopy, and differential thermal analysis, are discussed.

The article also presents the results of studies on the effect of ultrafine powders on the structure and properties of materials, as well as the determination of the optimal powder concentration in a transporting gas medium. In conclusion, the importance of further improving modification methods to create innovative materials with specific characteristics is highlighted.


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The American Journal of Applied Sciences

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TYPE

Original Research

PAGE NO.

20-26

DOI

10.37547/tajas/Volume07Issue03-04



OPEN ACCESS

SUBMITED

18 January 2025

ACCEPTED

16 February 2025

PUBLISHED

18 March 2025

VOLUME

Vol.07 Issue03 2025

CITATION

Khasanov Abdurashid Solievich, Utkir Mirzakamolovich Khalikulov, &
Djeparova Medine Narimanovna. (2025). Aspects of modification and
ccrystallization of high-alloy steels. The American Journal of Applied
Sciences, 7(03), 20

26.

https://doi.org/10.37547/tajas/Volume07Issue03-

04

COPYRIGHT

© 2025 Original content from this work may be used under the terms
of the creative commons attributes 4.0 License.

Aspects of modification
and ccrystallization of0
high-alloy steels

Khasanov Abdurashid Solievich

Professor, Dr. Sci., Almalyk BranchNational University of Science and
Technology "MISIS", Almalyk, Uzbekistan

Utkir Mirzakamolovich Khalikulov

Associate Professor, Almalyk Branch National University of Science and
Technology "MISIS", Almalyk, Uzbekistan

Djeparova Medine Narimanovna

Student Almalyk Branch National University of Science and Technology
"MISIS", Almalyk, Uzbekistan

Abstract:

This article examines current approaches to

modification and crystallization, as well as their practical
applications in the field of materials science. An analysis
of key modification tasks is provided, including the
management of material structures, enhancement of
their mechanical and chemical properties, and
optimization of thermal and electrical characteristics.

An overview of contemporary research dedicated to
steel crystallization processes is presented, with an
emphasis on the use of rare earth elements,
nanoparticles, and computer modeling methods.
Experimental techniques for studying crystallization and
modification processes, such as X-ray diffraction,
scanning electron microscopy, and differential thermal
analysis, are discussed.

The article also presents the results of studies on the
effect of ultrafine powders on the structure and
properties of materials, as well as the determination of
the optimal powder concentration in a transporting gas
medium. In conclusion, the importance of further
improving modification methods to create innovative
materials with specific characteristics is highlighted.

Keywords:

Modification, crystallization, nanoparticles,

metallurgy, materials, computer modeling, mechanical
properties, rare earth elements, ultrafine powders,
structural changes.


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Introduction:

Relevance of studying modification and

crystallization processes

The processes of modification and crystallization play
a key role in materials science and technological
development in various industries. The study of these
processes is relevant for the following reasons:

1.

Improvement of material quality

Modern technologies require materials with

enhanced mechanical, thermal, and chemical
properties.

Controlled crystallization minimizes defects

and improves the strength and wear resistance of
materials.

2.

Development of high-tech industries

In metallurgy, modification processes enhance

the casting characteristics of alloys.

In micro- and nanoelectronics, precise control

of crystallization is crucial for creating semiconductors
and superconductors.

In medicine, crystallization of biomaterials

affects biocompatibility and the longevity of implants.

3.

Economic

efficiency

and

resource

conservation

Optimization

of

crystallization

and

modification processes reduces production costs.

The use of modifiers enhances material

properties without significantly increasing the cost of
production.

4.

Adaptation

to

new

challenges

and

development of advanced materials

Research in this field contributes to the

creation of adaptive and self-healing materials.

New theoretical models help develop

materials with specified properties at the molecular
and atomic levels.

Thus, the study of modification and crystallization
processes is an essential direction in materials science
and engineering, determining the further development
of science and technology.

Main tasks and goals of material modification

Material modification aims to improve their properties
by changing their structure, phase composition, or
chemical composition. This process is widely applied in
metallurgy, ceramics, polymers, composites, and other
materials.

Main tasks of modification:

1.

Control of structure and crystallization

Control of grain size, shape, and distribution in

metals and polymers.

Formation of amorphous, nanostructured, or

crystalline phases with specific properties.

2.

Enhancement of mechanical properties

Increasing

strength,

hardness,

impact

toughness, and wear resistance.

Reducing brittleness and increasing plasticity.

3.

Improvement of chemical and corrosion

resistance

Enhancing resistance to oxidation, acids, alkalis,

and other aggressive environments.

Creating protective coatings and barrier layers.

4.

Optimization of thermal and electrical

properties

Regulation of thermal conductivity and heat

capacity of materials.

Improving electrical conductivity or, conversely,

creating dielectric materials.

5.

Creation of special functional materials

Development of superconductors, magnetic,

optical, piezoelectric, and biocompatible materials.

Production of materials with changeable or

adaptive properties (e.g., self-healing coatings).

6.

Economic efficiency and resource conservation

Reducing the need for expensive and rare earth

elements.

Increasing the service life of materials and

reducing replacement costs.

Main goals of modification:

1.

To impart new or improved properties to

materials

2.

To increase the service life of products

3.

To create competitive materials for high-tech

industries

4.

To reduce production and operational costs

5.

To minimize environmental impact by creating

eco-friendly materials

Thus, material modification is a key tool for creating
innovative solutions in various fields of science and
technology.

Review of Modern Research Directions in Steel
Crystallization

Currently, there is no universal theory that explains the
modification process for all melt treatment methods.
The main reason for this is the lack of a comprehensive


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crystallization theory. Modern approaches to studying
crystallization rely on various theories of the structural
state of Fe-C alloys, which determine the mechanism
of formation of crystallization centers and the
corresponding modification theories. Each of these is
generally experimentally validated through the
development of new types of modifiers [2].

To date, there are more than 10 modification theories
for Fe-C alloys [1], which are closely linked to
crystallization theories. The foundations of metal
crystallization theory were laid by D.K. Chernov in the
1870s when he first introduced the concept of
crystallization rate [3]. In the early 20th century, G.
Tamman expanded these studies by formulating the
concept of the rate of formation of crystallization
centers and establishing their dependence on the
degree of undercooling.

Modification and crystallization processes play an
important role in the development of modern
materials, ensuring their optimal physical-mechanical
and operational characteristics. Crystallization is the
process of a substance transitioning from an
amorphous state to a crystalline one, which is
regulated by various factors such as temperature,
pressure, and the presence of impurities. Modification,
in turn, involves changing the properties of materials
through alloying, heat treatment, or the introduction
of nanoparticles. Research in this area has a wide range
of applications, from metallurgy to biomedical
technologies.

Steel crystallization research focuses on improving its
properties, such as strength, corrosion resistance,
impact toughness, and wear resistance. Modern
directions in this field include:

Application of molecular dynamics and machine
learning methods for predicting grain growth;

Development of digital models for thermodynamic
solidification processes;

Introduction of rare-earth elements (e.g., niobium,
vanadium, titanium) to control grain boundary
processes;

Optimization of chemical composition to enhance
mechanical properties;

Use of nanoparticles in crystallization processes;

Addition of nanostructured modifiers to control
the size and orientation of crystallographic grains;

Study of the influence of carbon and oxide
nanoparticles on crystallization rate;

Heat treatment and accelerated crystallization

methods;

Application of directed hardening and controlled
cooling for the formation of ultrafine-grained
structures;

Use of electromagnetic influence and ultrasonic
technologies to control solidification;

Additive manufacturing technologies and rapidly
quenched alloys;

Development of laser and electron-beam surfacing
methods for creating high-strength steel structures;

Investigation of crystallization processes under
rapid cooling conditions, characteristic of additive
manufacturing.

Experimental Methods:

Differential thermal analysis (DTA) to study the kinetics
of crystallization.

X-ray diffraction analysis to determine phase
composition.

Scanning electron microscopy (SEM) to analyze the
morphology of structures.

Theoretical Approaches:

Computer modeling (Monte Carlo method, molecular
dynamics) for predicting the nucleation and growth of
crystals.

Thermodynamic calculations of the influence of various
additives on structure formation.

Materials modification methods:

Alloying of steels with rare-earth elements to improve
mechanical properties.

Introduction of nanostructured additives to enhance
corrosion resistance.

Use of ultrasonic treatments to regulate grain sizes in
metals.

In the study to select the optimal composition for
modifying chromium-molybdenum steel, ultradispersed
powders of molybdenum (Mo), vanadium (V), and
aluminum (Al) were used. The method chosen for
synthesizing ultradisperse powders was the production
of fine-disperse metallic, oxide, nitride, and carbide
powders using the electrical explosion of a conductor
(metallic wire with a diameter of 0.1-1.0 mm) by passing
a powerful current pulse (duration of 10^-5 to 10^-7 s)
with a current density of 10^4-10^6 A·mm^-2 through
the wire. Vanadium wires (0.28 mm in diameter and 40
mm in length) were selected as consumables. The
voltage for the graphite electrode was set to 30 kV.
Molybdenum wire (0.30 mm in diameter and 60 mm in
length) at 30 kV and aluminum wire (0.30 mm in


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diameter and 130 mm in length) at 21 kV were also
used as starting materials.

Further, micrographs of the obtained ultradispersed

powders produced by the electrical explosion of the
conductor were taken using an electron-optical
metallographic microscope (OEM ODM) (Fig. 1).

Figure 1. Micrographs obtained in the electron-optical metallographic microscope OEM ODM of vanadium

and molybdenum electropowders.

Based on the results of this electron-optical analysis, a
table was created for the data of the ultradispersed

powders (Table 1), which were used as modifiers.

Table 1. Properties of Modifiers

Powder Modifier

Specific surface area,

m²/g

Particle diameter, nm

Vanadium

2,56

123

Molybdenum

4,73

128

Aluminum

15,4

146

It should be noted that the synthesis method using
electrical explosion utilized aluminum powders as the
starting material for aluminum oxyhydroxide.

Accordingly,

the

micrographs

of

aluminum

oxyhydroxide are presented in Figure 2.

Figure 2. Micrographs obtained in the electron-optical metallographic microscope OEM ODM of aluminum

oxyhydroxide.


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RESULTS

The studies showed that the introduction of modifying
additives significantly affects the rate and nature of
crystallization.

Key results include:

Alloying aluminum alloys with zirconium and titanium
reduced the grain size by 30%, which improved their
mechanical properties.

The use of silica nanoparticles in polymer materials
increased their thermal stability by 20%.

The application of computer modeling confirmed
theoretical assumptions about the effect of activators
and inhibitors on crystallization, which allows for the
prediction of material properties with high accuracy.

Study of the optimal concentration of ultradispersed
powders in the transporting gas. During the work,
studies were conducted to determine the optimal
concentration of ultradispersed powders in the
transporting gas. The rationalization of the
concentration was carried out based on the following
technological parameters:

1.

Dendrite Thickness SSS (μm)

2.

Dendrite Width eee (μm)

3.

Volume of the Electrode Metal Droplet vvv

(mm³)

To determine the optimal concentration of modifier
powders in the transporting gas, a dimensionless
function was calculated using the following formula:

f= S

6

• еб

V

6

,

(1)

Where: S6, is the dimensionless dendrite thickness,; еб

- is the dimensionless dendrite width; V6 - is the
dimensionless volume of the electrode metal droplet.

Based on a multifactorial experiment that studied the
effect

of

ultradispersed

powder

modifiers'

concentration on the quality of the surface layer, the
rational concentration was determined. The minimum
value of the dimensionless function

𝑓

was 0.2 mg/cm³ for the surface layer.

The obtained results confirm the effectiveness of
various modification methods that allow control over
the structure and properties of materials. Key points
include:

The use of crystallization activators accelerates the
phase transition, ensuring uniform structure
formation.

The application of computational modeling
methods has become an indispensable tool for
predicting the properties of new materials.

The maximum modification effect of the surface layer is
achieved with a concentration of nanostructured
powders in the transporting gas of 0.2 mg/m³. A
reduction in concentration results in insufficient
modification, while an increase in concentration hinders
the formation of a defect-free surface layer.

The analysis of the fine structure of the surface layer
using atomic force microscopy revealed the presence of
particles sized 100

200 nm. These particles are

ultradispersed powders that did not dissolve during the
high-temperature treatment process, making them
effective inoculants that contribute to grain refinement
of the metal (Fig. 3).

Studies were conducted to determine the optimal
concentration of ultradispersed powders in the
transporting gas.

The

rationalization

of

the

concentration

of

ultradispersed powders in the transporting gas was
based on the following technological parameters:

1.

Dendrite thickness s (μm)

2.

Dendrite width e (μm)

3.

Volume of the electrode metal droplet v (mm³)

To

determine

the

optimal

concentration

of

ultradispersed modifier powders in the transporting
gas, the dimensionless function fff was calculated using
the following expression:

f= S

6

• еб V

6

, (1)

Where: S6, is the dimensionless dendrite thickness,; еб

- is the dimensionless dendrite width; V6 - is the
dimensionless volume of the electrode metal droplet.

Based on the conducted multifactorial experiment on
the effect of various concentrations of ultradispersed
modifier powders in the transporting gas on the quality
of the surface layer, the optimal concentration was
determined, at which the minimum value of the
dimensionless function

𝑓

was 0.2 milligrams per cubic

centimeter of the surface layer.

Discussion. The obtained data confirm the effectiveness
of various modification methods that allow for targeted
control over the structure and properties of materials. It
is important to note that:

The application of crystallization activators

accelerates the phase transition process, ensuring
uniform structure formation.

Computer

modeling

has

become

an

indispensable tool for predicting the properties of new
materials.


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The optimal effect of surface layer

modification is achieved with a concentration of
nanostructured powders in the transporting gas of 0.2
mg/m³. A decrease in the concentration of ultrafine
powders leads to insufficient modification, while an
increase in concentration prevents the formation of a
defect-free surface layer.

Analysis of the fine structure of the surface layer

using atomic force microscopy revealed the presence of
particles sized 100

200 nm. These particles are ultrafine

powders that did not dissolve during high-temperature
processing and act as effective inoculants, promoting
the grain refinement of the metal (Figure 3).

Figure 3. Results of modification with ultrafine powders of Al2O3 and vanadium.

Further research should focus on studying the
interactions of nanoparticles with the matrix of
materials to create composites with enhanced
properties.

CONCLUSION

Modern theories of modification and crystallization
significantly expand the possibilities of materials
science. The development of experimental methods
and computer modeling contributes to the creation of
new materials with tailored properties, opening up
prospects in metallurgy, the polymer industry,
medicine, and other sectors. Further studies in this
field will help optimize existing technologies and
develop new methods for controlling crystallization
and modification processes.

REFERENCES

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N.I. Kakhovsky, K.A. Yushchenko, Z.V. Yushkevich //
Automatic Welding

1963.

No. 12.

pp. 49-57.

Kakhovsky N.I. Welding of corrosion-resistant austenitic
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steel

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effects from pharmaceutical preparations / I.F.
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References

Kakhovsky N.I. Electrogas welding of corrosion-resistant ferritic-austenitic steels type 21-3 and 21-5 / N.I. Kakhovsky, K.A. Yushchenko, Z.V. Yushkevich // Automatic Welding – 1963. – No. 12. – pp. 49-57.

Kakhovsky N.I. Welding of corrosion-resistant austenitic chromium-nickel-manganese-nitrogen steel 0Kh17N5G9AB (ZP55) / K.A. Yushchenko, V.G. Fartushny, Z.V. Yushkevich // Automatic Welding – 1963. – No. 7. – pp. 21-28.

Poletika I.M. Formation of corrosion-resistant coatings by cladding in a beam of relativistic electrons / I.M. Poletika, M.G. Golkovsky, M.V. Perovskaya, E.N. Belyakov, R.A. Salimov, V.A. Bataev, Y.A. Sazanov // Prospective Materials – 2006. – No. 2. – pp. 80-86.

Tsvirkun O.A. Hardening and protection of the surface of steel Kh12 by electro-explosive alloying / O.A. Tsvirkun, E.A. Budovskikh, E.E. Rudneva, V.F. Goryushkin, V.E. Gromov // Journal of Fundamental Materials – 2007. – Vol. 1. – No. 3. – pp. 117-119.

Goryushkin I.F. Relative resistance of various tool and corrosion-resistant steels to mechanical and chemical effects from pharmaceutical preparations / I.F. Goryushkin, S.A. Lezhayeva, A.A. Permyakov, N.N. Shevchenko // Bulletin of the Mining and Metallurgical Section of the Russian Academy of Natural Sciences. Metallurgy Division – 2002. – No. 11. – pp. 59-65.