1. Introduction

In the era of exhaustion of natural resources as well as of continuous development of the modern industry, the technologies for surface treatment are becoming increasingly important. There exist a number of technologies for surface manufacturing of the materials, including electrochemical processes, electrical discharge processes, additive manufacturing, etc. [1–3].

Considering the electrochemical method, it has been used for synthesizing of nanostructures and manufacturing of advanced materials since the methods are known as cost-effective and resourceful. This technique is based on the removing of metal by electrochemical process, and it is used for treatment of extremely hard materials and materials that cannot be treated by the conventional techniques. However, some drawbacks such as long process time and too high

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

temperature required can be mentioned. Furthermore, the formation of environmental pollution due to the use of chemicals and the need that the materials must be conductors can also be considered as limitations [1].

rapidly cools down. The processes of fast heating and cooling reflect to structural transformations, changes in the chemical composition, melting of the surface, etc. According to the maximum temperature of the heating, several processes can be defined: (i) When, during the heating, the temperature is lower than the melting point of the treated specimen, the material remains in solid-state condition, but some phase and structural transformations may occur. Such technological conditions are widely used for a surface hardening of the materials [10]. (ii) When the maximum temperature is higher than the melting point of the specimen and, in the same time, lower than the boiling point, the material becomes in liquid phase condition. Such techniques are used for alloying and cladding processes [11–13]. (iii) When the temperature is higher than the boiling point of the material, the treated material is partially evaporated. Such technologies are used for a deposition of coatings (electron beam evaporation, laser deposition,

Surface Manufacturing of Materials by High Energy Fluxes

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Currently, the additive manufacturing techniques are considered for different aerospace applications, such as on-orbit constructions of space structures, a manufacturing of small multifunctional systems for astronauts for fabrication of spare parts, etc. Applying these techniques in the space, the typical pressure is up to 10<sup>17</sup> mbar. This means that for electron beam processing a vacuum chamber and the equipment are not necessary and the process can be realized directly in the space environment [5]. Also, the discussed techniques are widely used in the field of automotive and aircraft industries for manufacturing of different components and tools, for the needs of the modern medicine, for biomedical applications,

This chapter aims to summarize the topics related to the application of a surface treatment by high energy fluxes (i.e., electron beams and laser beams) for developing of new multifunctional materials, as well as to modify their surface properties. We present and discuss the methods and techniques for development and improvement of advanced materials by means of alloying,

For both types of techniques (i.e., electron and laser beam), the beam power and power density are of the important process parameters. In the case of laser beam, it can be set directly, while for e-beam it is a product of the accelerating voltage and the beam current. For example, typical values for the accelerating voltage are from 50 to 150 kV. With an increase of the beam power, the kinetic energy of the electrons also increases, which causes an increase in the penetration depth of the beam. The beam power density is an important parameter for the

The speed of the specimen motion during the process is also a basic parameter. As a result of this movement, the heat is transferred to the volume of the material. It is responsible for the heating and cooling rate as well as for the solidification speed. With an increase of the speed of the specimen motion, the heat input decreases. The beam power and the speed of the specimen motion are responsible for the volume of the manufactured zone, the thickness,

alloying operation since it affects the forces acting in the molten material [16].

etc.), laser ablation, in the field of а laser drilling [13–15].

cladding, and hardening via electron and laser beams.

2. Technological parameters

and many more [5].

and the width [5].

The electrical discharge machining process is another method which is used for manufacturing of the materials. This technique is based on the removing of the material using electrical discharge. Series of rapidly recurring current discharge between two electrodes were applied which are responsible for the removal of the material. The method is often used for prototype production and manufacturing of parts, especially for the needs of the automotive and aircraft industries. However, the slow rate of the material removal and the requirement of conductive materials that can be manufactured by the discussed method are of the major drawbacks [2].

Promising techniques for fabrication of new materials with unique properties and for modification of their structure are the additive manufacturing technologies. They are based on layerby-layer fabrication of components [3]. The additive technologies include several techniques for materials' treatment, such as ultrasonic processes, electron beam processes, laser beam processes, etc. The ultrasonic processing is a revolutionary processing technology widely used for welding and joining. It is based on the scrubbing together with ultrasonic vibrations under controlled pressure or normal load. Nevertheless, this technique is not capable to melt the treated area and operates at a temperature significantly lower than the melting point of the manufactured materials. Thus, although the discussed technique is a revolutionary process for welding and joining, it is not suitable for processes such as surface alloying, cladding, etc. [4].

The methods of a surface treatment by high energy fluxes (HEFs), which are a part of the additive technologies, are intensively used for formation of surface alloys, as well as for modification of the surface structure of different materials. Their main advantage is the precise control of the energy input, which alloys the controlling of the structure and properties of the treated materials. Furthermore, in comparison to traditional manufacturing, some benefits of the additive technologies can be mentioned [5]:


The processes used for surface manufacturing of the materials are treatment by fluxes of photons (laser radiation) or accelerated electrons (electron beam). During this process, the manufactured material is irradiated by electron or laser beam. When the flux of the photons or accelerated electrons interacts with the treated surface, the work-piece is heated and forms thermal distribution from the surface to the bulk [6–9]. After the irradiation, the sample rapidly cools down. The processes of fast heating and cooling reflect to structural transformations, changes in the chemical composition, melting of the surface, etc. According to the maximum temperature of the heating, several processes can be defined: (i) When, during the heating, the temperature is lower than the melting point of the treated specimen, the material remains in solid-state condition, but some phase and structural transformations may occur. Such technological conditions are widely used for a surface hardening of the materials [10]. (ii) When the maximum temperature is higher than the melting point of the specimen and, in the same time, lower than the boiling point, the material becomes in liquid phase condition. Such techniques are used for alloying and cladding processes [11–13]. (iii) When the temperature is higher than the boiling point of the material, the treated material is partially evaporated. Such technologies are used for a deposition of coatings (electron beam evaporation, laser deposition, etc.), laser ablation, in the field of а laser drilling [13–15].

Currently, the additive manufacturing techniques are considered for different aerospace applications, such as on-orbit constructions of space structures, a manufacturing of small multifunctional systems for astronauts for fabrication of spare parts, etc. Applying these techniques in the space, the typical pressure is up to 10<sup>17</sup> mbar. This means that for electron beam processing a vacuum chamber and the equipment are not necessary and the process can be realized directly in the space environment [5]. Also, the discussed techniques are widely used in the field of automotive and aircraft industries for manufacturing of different components and tools, for the needs of the modern medicine, for biomedical applications, and many more [5].

This chapter aims to summarize the topics related to the application of a surface treatment by high energy fluxes (i.e., electron beams and laser beams) for developing of new multifunctional materials, as well as to modify their surface properties. We present and discuss the methods and techniques for development and improvement of advanced materials by means of alloying, cladding, and hardening via electron and laser beams.
