Electron-Beam Surface Treatment of Metals and Alloys: Techniques and Trends

Abstract

During the last decades, electron-beam treatment technologies (EBTT) have been widely used for surface modification of metals and alloys. The EBT methods are known as accurate and efficient. They have many advantages in comparison with the conventional techniques, such as very short technological process time, uniform distribution of the energy of the electron beam, which allows a precise control of the beam parameters and formed structure and properties of the materials, etc. Moreover, electron-beam treatment technologies are a part of the additive techniques, which are known as modern methods for manufacturing of new materials with unique functional properties. Currently, modern trends in the surface treatment of metals and alloys are based on the combination of electron-beam technologies with other methods, such as thin film deposition, plasma nitriding, etc. This approach results in a significant improvement in the surface properties of the materials which opens new potential applications and can involve them into new industrial fields. This paper aims to summarize the topics related to the manufacturing and surface treatment of metals and alloys by means of electron-beam technologies. Based on a literature review, the development and growth of EBT are considered in details. The benefits of these technologies—as well as their combination with other methods—are extensively discussed.

Electron Beam Surface Hardening

“…The process involves the excitation and emission of electrons from the cathode, usually made of tungsten or a tungsten alloy. Electrons are first accelerated using very high voltage (even 300 kV) and, next deflected and directed to the working chamber using electromagnetic coils [10][11][12][13]. The design of the electron gun is presented in Figure 2.…”

“…The proportion of the mass subjected to electron beam hardening to the mass not subjected to hardening should be low enough for the latter to absorb heat from the surface. The above-named absorption should be fast enough to exceed the critical rate and enable the martensitic or bainitic transformation [10,12,[18][19][20].…”

“…The easy change of focusing current and the dynamic deflection of the beam enable the performance of the hardening process using both the focused and defocused electron beam, in the continuous, pulsed or continuously oscillating deflected mode (dynamic, scanning). The shape of oscillation is freely programmable, which facilitates the precise hardening of selected surfaces [10,[18][19][20]. Figure 3 presents exemplary electron beam scanning related to various oscillation frequencies.…”

“…Figure 3 presents exemplary electron beam scanning related to various oscillation frequencies. Figure 4 The primary advantages of electron beam hardening [10,12,13,[18][19][20] are the following: -metallurgical purity of the process (performed in vacuum), -precise computer-controlled deflection and focusing of the beam, -higher (in comparison with other technologies) heating rates (of up to 109 K/s), where the heating of the surface of an element is faster than its heat absorbability (resulting from the heat conductivity of a given material), -precise adjustment of process parameters, -high process repeatability, -easy automation, -high process precision, -high energy conversion efficiency (exceeding 90%). Exemplary applications of the electron beam surface hardening process are presented in Table 1.…”

Effect of CeO2 on Corrosion Resistance of High-Current Pulsed Electron Beam Treated Pressureless Sintering Al-20SiC Composites

“…Hutsaylyuk reported that in recent decades, electron beam processing technology has been widely used for surface modification of pure metals and their alloys. This technology has significantly improved the surface properties of materials, shows new potential applications, and is promoted for industrial applications [23].…”