High velocity oxy-fuel spraying PDF

PREFACE

HVOF spraying is widely used now for many industrial applications and is probably the best among the thermal spray techniques for some specific needs, e.g., for deposition of the cermet coatings. Both industry and research laboratories have a need to improve their understanding of the HVOF spray processing in order to develop the optimum conditions and effective control of HVOF spraying which enables production of the quality coatings. Addressing this need is the main objective of this book.

HVOF spraying has proved to be technically feasible and has become indispensable in many areas of high technology, such as aerospace industry, automobile manufacturing, powder production, electronics, chemical industry, pulp and paper industry, machinery manufacturing, petroleum and petrochemical industry, biomedical applications, etc.

The world industry meets serious new challenges. A new emphasis on the conservation of materials will bring higher demand for HVOF sprayed coatings to increase wear and corrosion characteristics of many different substrates. It is expected that the newly developed multicomponent coatings (metastable, mixed, multilayered or graded with carbides, oxides, nitrides and cermets), special coating structures (nanocrystalline and amorphous), superhard deposits and polymer coatings will soon become standard items in the list of engineering: materials.

The world thermal spray market is continuously growing. According to the estimates of the Sulzer Metco AG, in 2000 it could achieve $5000 million and the share of the HVOF spray technology is expected to be about 25%.

The investments in the HVOF spray technology are highly effective. The considerable research and development costs bring fast benefits due to the market demands and sales of the new production equipment. In many practical situations HVOF spraying offers complex solutions of challenges of the modern technology and gives high quality, operational reliability, product life span and environmental friendliness. The higher manufacturing costs associated with deposition of functional coatings are well offset by the outstanding operational properties of the final product.

The present book covers the main aspects relating to fundamentals and applications of HVOF spraying. The first chapter deals with the basic methods of characterisation of materials structure, which include optical microscopy, transmission electron microscopy and scanning electron microscopy, There are many references in literature relating to the standard methods of characterisation, however, we guess that a very simple general view on these issues would help the readers to refresh their memories.

Edited by: V.V. Sobolev, J.M. Guilemany, J. Nutting