**Preface to "Development of Laser Welding and Surface Treatment of Metals"**

Welding is a strong industry in various regions of the world, regardless of the level of economic development. However, in countries with a high level of economic development, the most advanced welding technologies and materials processing technologies are dynamically developed. One of the most advanced technologies of welding and materials processing are based on high power density heat sources, such as the focused laser beam.

The aim of the book was to present the latest achievements in the field of research results and the state of the art in the field of laser welding and surface treatment by experienced and also young scientists who are dynamically active in this field.

The main scope of the book deals with important issues related to the development of science and technology in the field of application the laser beam for joining, surface treatment and coatings. However, the thematic scope is not limited only to the above issues. The scope of the book covers also issue related with advances in computational modelling of laser and arc heat sources, very unique techniques of underwater welding, advanced and unique techniques of localised forced cooling the weld metal during welding, hybrid process of laser deposition of metal matrix composite coatings under cryogenic conditions, microstructural and mechanical characterisation of coatings and joints produced by different welding technologies.

The motivations for writing the book was collecting the valuable information, both theoretical and practical research results in the field of advanced technologies of joining, surface treatment and coatings, quality control and assessment, as well as management of the technological processes.

The book is addressed to young scientists, engineers, and students in the field of welding and surface engineering, materials science and manufacturing engineering. The book contains 22 chapters presented results of interesting and recent researches.

The wide range of experimental, numerical or analytical study conducted and presented by 58 authors, representing 19 academic or research centers and 3 industrial centers, from 5 countries (Poland, China, Slovakia, Lithuania, and Ukraine) and 16 cities, proved the topicality, and importance of this Special Issue.

Concluding, I thank to all the authors, editors, and technical assistants who have made invaluable contributions to make this edition of the book a success.

> **Aleksander Lisiecki** *Editor*
