Conflict of interest

The authors of [34, 65] have studied an electron beam surface hardening of previously nitrogen-alloyed steel. Their results show a significant increase in the microhardness as well as double improvement of the wear resistance. The authors of the discussed studies [34, 65] claimed that the reasons of these improvements of the functional properties are the refined microstructure consisting of α-solid solution (nitrous martensite) and γ-solid solution (nitrous austenite) and dispersed fine nitride precipitates. Ormanova et al. [22] have presented a combined method for surface modification of tool steels, consisting of electron beam hardening followed by plasma nitriding and subsequent electron beam hardening, and the results demonstrate a hardness of 760 HV after the electron beam treatment and plasma hardening. The application of additional electron beam treatment process tends to a slight decrease in the

hardness due to structural transformation and reduction of the amount of N atoms.

techniques is provided at the discussions of each surface manufacturing process.

extensively introduced for different industrial applications.

The current state of the surface manufacturing of the materials by means of high energy fluxes (electron and laser beams), including surface alloying, cladding, and hardening, has been discussed in the present book chapter. The presented data are based on our own experience as well as on the available studies in the literature. The various applications of the high energy fluxes in the field of the surface manufacturing were demonstrated with a focus on the relationship between the technological processes and the properties. It was shown that the electron and laser beams have a number of benefits as a small comparison between both

The area of future developments of the surface manufacturing by means of high energy fluxes will be concentrated on the optimization of the techniques, processes as well as modeling and simulations. Considering the fact that the number of the machines for high energy fluxes manufacturing, installed in the industry, extensively grows, these technologies should be rapidly incorporated in the wide range of the industry, such as aerospace, automotive, railway,

Up to now, the materials which are extensively treated and manufactured by high energy fluxes are the steels as well as small amount of other high-performance materials, such as titanium aluminides. It can be concluded that the state of research on the applications of high energy fluxes in the field of the surface manufacturing processes is well developed and

The authors acknowledge the financial support of project DFNP-17-1 "Selective electron-beam surface treatment of light metals" under the Assistance for Young Scientist program of the

6. Summary

82 Advanced Surface Engineering Research

biomedicine, etc.

Acknowledgements

Bulgarian Academy of Sciences.

The authors have no conflict of interest to declare.
