Surface Engineering of Metals - Principles, Equipment and Technologies Part 1 potx

Part I, devoted to general fundamentals of surface engineering, tains a history of its development and a distinction is suggested betweensuperficial layers and coatings.. Further, but fo

Surface engineering is a new field of science and technology Although thespecific topical groups included in its domain have been known and prac-tically applied in other areas, it is only in the last few years that surfaceengineering has been recognized as an individual discipline of appliedscience This book is the first in the world to provide a complex treatment

of problems related to surface engineering

The material of this book has been treated in two parts, so designed as

to allow extension in future editions

Part I, devoted to general fundamentals of surface engineering, tains a history of its development and a distinction is suggested betweensuperficial layers and coatings Further, but foremost, the basic potentialand usable properties of superficial layers and coatings are discussed,with an explanation of their concept, interaction with other propertiesand the significance of these properties for the proper selection and func-tioning of surface layers This part is enriched by a general description ofdifferent types of coatings

con-Part II contains an original classification of production methods ofsurface layers This part presents the latest technologies in this field, char-acterized by directional or beam interaction of particles or of the heatingmedium with the treated surface Due to its modest length, the book doesnot discuss older methods which are well known and widely used.This edition is a revised version of the first Polish edition of the bookentitled “Surface Engineering of Metals - Principles, Equipment, Tech-nologies”, published by Wydawnictwa Naukowo-Techniczne (Science-Tech-nological Publications), Warsaw, 1995

The authors express their gratitude to all who in any way contributed tothe presentation of the broad array of problems of surface engineering in thisform In particular, our thanks go to professors: J Kaczmarek,K.J Kurzyd≈owski, R Marczak, B Ralph, J Senatorski, J Tacikowski and

W W≈osiñski, as well as doctors S Janowski, K Miernik and J Walkowiczfor their discussion regarding the book and constructive suggestions.Special words of thanks are due to Dr A Mazurkiewicz, Director ofthe Institute of Terotechnology in Radom, for his invaluable help in thepreparation of the work for print, and to the publisher, WydawnictwaNaukowo-Techniczne, for making information material from the first edi-tion available The authors thank Mr A Kirsz for expert technical assistancefor providing camera-ready text

The authors

Table of Contents

Engineering

1 The concept of surface engineering

1.1 The term ”surface engineering”

1.2 Scope of topics forming the concept of surface

engineeringReferences

2 Development of surface engineering

2.1 History of development of surface engineering 2.1.1 General laws of development

2.1.2 History of development of metallic structuralmaterials

2.1.3 History of development of the technology of

surface improvement of structural materials2.2 Surface engineering today

2.2.1 General areas of activity of surface engineering2.2.2 Significance of surface engineering

2.3 Directions of development of surface engineering2.3.1 Perfection and combination of methods of

manufacturing of surface layers 2.3.2 Design of surface layers, based on mathematicalmodeling

2.3.3 Micro and nanometric testing

2.3.4 Rational application of surface layers

References

3 The solid surface

3.1 The significance of the surface

3.2 The surface - geometrical concept

3.3 The surface - mechanical concept

3.4 The surface - physico-chemical concept

3.4.1 The phase

3.4.2 Interphase surface - a physical surface

3.4.3 Surface energy

3.4.4 Surface phenomena

References

4 Surface layers

References

5 The superficial layer

5.1 Development of concepts regarding the superficiallayer

5.2 Shaping of the superficial layer

5.3 Structure of the superficial layer

5.3.1 Simplified models of the superficial layer

5.3.2 The developed model of the superficial layer

5.4 A general characteristic of the superficial layerobtained by machining

5.5 Physical description of the superficial layer

5.6 Strengthening and weakening of the superficiallayer

5.7 Potential properties of the superficial layer

5.7.1 Geometrical parameters of the superficial layer 5.7.1.1 Three-dimensional structure of the surface

5.7.1.2 Surface roughness

5.7.1.3 Structural flaws of the three-dimensional

surface

5.7.2 Stereometric-physico-chemical parameters ofthe superficial layer

6.1 The concept of the coatings

6.2 Structure of the coating

6.4 Potential properties of coatings

6.4.1 Geometrical parameters of coatings

6.4.1.1 Thickness

6.4.1.2 Three-dimensional structure of the surface

6.4.1.3 Surface unevenness

6.4.1.4 Defects of the three-dimensional structure

6.4.2 Geometric and physico-chemical parameters

6.5.2.5 Specific decorative properties

6.6 Significance and directions of development

of coatings

References

surface layers

1 Formation of technological surface layers

1.1 Techniques of formation of technological surfacelayers

1.1.6 Physical techniques

1.2 Classification of techniques of producing

technological surface layers

References

2 Electron beam technology

2.1 Advent and development of electron beamtechnology

2.2 Physical principles underlying the functioning

of electron beam equipment

2.2.1 Electron emission

2.2.2 Thermoelectron emission

2.2.3 Utilization of plasma as a source of electrons 2.2.4 Acceleration of electrons

2.2.5 Electron beam control

2.2.6 Vacuum in electron equipment

2.3 Electron beam heaters

2.3.1 Electron guns

2.3.1.1 Thermal emission guns

2.3.1.2 Plasma emission guns

2.3.2 Design of electron beam heaters

2.3.3 Types of beams and patterns

2.4 Physical fundamentals of interaction of electronbeam with treated material

2.4.1 Mechanism of interaction of electron beam withtreated material

2.4.2 Efficiency of electron beam heating

2.4.3 Rate of heating and cooling

2.5 Electron beam techniques

3.2 Physical fundamentals of lasers

3.2.1 Spontaneous and stimulated emission

3.2.2 Laser action

3.2.2.1 Inversion of occupation of energy levels

3.2.2.2 Optical resonator

3.2.3 Single-mode and multi-mode laser beams

3.3 Lasers and laser heaters

3.3.1 General design of lasers

3.3.2 Molecuar CO2 lasers

3.3.2.1 General characteristic

3.3.2.2 Lasers with slow longitudinal flow (diffusioncooled)

3.3.2.3 Lasers with fast longitudinal flow

3.3.2.4 Lasers with transverse flow

3.3.3 Solid Nd-YAG lasers

3.3.4 Continuous and pulse laser operation

3.3.5 Laser heaters and machinetools

3.4 Physical fundamentals of laser heating

3.4.1 Properties of laser heating

3.4.2 The role surface absorption in laser heating

3.4.3 Depth of penetration of photons into the metal 3.4.4 Laser heating stages

3.4.5 Temperature distribution in laser-heated material 3.4.6 Laser beam control

3.5.4.3 Pyrolytic and photochemical formation

of coatings3.5.4.4 Formation of coatings by chemical methods

(LCVD)3.6 Application of laser heating in surface

engineering

References

4 Implantation techniques (ion implantation)

4.1 Development of ion implantation technology 4.1.1 Chronology of development

4.1.2 General characteristic of plasma and beam

implantation of ions

4.2 Plasma source ion implantation

4.3 Physical principles of ion beam implantation 4.3.1 Continuous ion beam implantation

4.3.2 Pulse ion beam implantation

4.4 Ion beam implantation equipment

4.4.1 Continuous ion beam implanters

4.4.2 Pulse ion implanters

4.5 Ion beam implantation techniques

4.6 Modification of properties of implanted

4.6.5 Other properties of implanted materials

4.7 Application of implantation technology

4.8 Advantages and disadvantages of ion implantationtechniques

References

5 Glow discharge methods and CVD technology

5.1 Conception and development of glow dischargemethods

5.2 Physico-chemical basis of glow discharge

5.2.3 Chemisorption in glow discharge treatments 5.3 Glow discharge furnaces

5.4 Glow discharge applications

5.4.1 Glow discharge nitriding

5.4.2 Glow discharge boriding

of substrate from entire liquid surface

6.2.3.2 Techniques utilizing local evaporation

6.2.3.3 Techniques utilizing direct sputtering

6.2.3.4 Techniques utilizing deposition from ion beams 6.3 Equipment for coating deposition by PVD

6.4.3.2 Models of coating deposition

6.4.4 Preparation of substrate for coating deposition 6.4.4.1 Requirements to be met by the coated surface 6.4.4.2 Initial cleaning

6.4.4.3 Final (ion) cleaning

6.5 Service characteristics of coatings deposited

part I

General Fundamentals

of Surface Engineering

chapter one

The concept of surface

engineering

1.1 The term ”surface engineering”

The word engineering stems from the French language (s’ingenier - to

con-template, rack one’s brains, strain oneself, exert oneself) and in the pasthad one meaning, while presently it has several meanings, all fairly close Inthe past it was a skill; presently it is mainly a science relating to the design ofshape or properties of materials and their manufacturing processes

Originally engineering encompassed the art of building fortifications,strongholds and other elements of defense systems In 18th - 19th centuryEurope we see the beginnings of differentiation between military and civil-ian engineering In more modern times the concept of engineering em-braced the art of design and construction of all types of structures (withthe exception of buildings) and various engineering branches were distin-guished: civil, hydro-, maritime, sanitary, forestry

After World War II, the influence of Anglo-Saxon countries caused thespread in Europe of the US - born concept of social engineering Quiterecently, a new branch of science, termed environmental engineering, cameinto existence

It was also during this last century, especially after World War II, thatthe term engineering was broadened to encompass some areas of humanknowledge, more particularly those connected with applied research, e.g.the science of unit operations used in the chemical and related industriesand the subsequent development of chemical equipment (chemical engi-neering), or the applied science drawing on the theoretical achievements

of genetics in the breeding of animals, cultivation of plants and in cine (genetic engineering)

medi-Created and in use are such concepts as: biomedical engineering, trical engineering, reliability engineering, programming engineering, com-munications engineering, aerospace engineering, process engineering, me-chanical, ion beam, corrosion and other types of engineering

elec-The early 70s saw the importation from the US to Europe of the concept of

material engineering, created in the 60s and embracing the “scientific

disci-pline dealing with the investigation of the structure of materials, as well asimprovement and the obtaining of new materials with predicted and repro-ducible properties.” (Scientific and Technical Lexicon, WNT, Warsaw 1984)

Departments, chairs, institutes and even entire faculties of material ing have sprung up.

engineer-It follows from the above definition that materials engineering deals withthe investigation of the structure of and the design of different materials,including composites It does not follow, on the other hand, although it can-not be excluded, that materials engineering deals specifically with problems

of enhancement or modification of surface properties of materials

It is probably due to this that the new term surface engineering1 was coinedfor the first time in England in the 70s In the early 70s the Surface Engineer-ing Society, affiliated with the Welding Institute in Abington, was inaugu-rated At first, it focused mainly on various aspects of welding and thermalspraying and gradually it broadened its scope of interest Next, the WolfsonInstitute for Surface Engineering was created at the University of Birming-ham, initially concerned mainly with problems stemming from surface diffu-sion treatments and their connection with vacuum technology, graduallybroadening the range of activity to other methods of formation of surfacelayers

The year 1985 saw the first edition of the quarterly “Surface Engineering”,published by the Wolfson Institute for Surface Engineering jointly with theSurface Engineering Society As of 1987 another quarterly of a scientific-re-search and technical nature was published under the same title, as thecombination of two periodicals: “Surfacing Journal International” and “Sur-face Engineering” This quarterly deals with thermal spraying technologies,layer formation by PVD and CVD, electron and laser beam hardening, ionimplantation, shot peening, surface alloying by conventional and plasmaprocesses and generally with technologies of surface layer formation andwith some coating technologies Problems of coatings, especially paint, plat-ing and other types, are dealt with by other periodicals (e.g., “Surface andCoatings Technology”, “Coatings”, “Metalloberfläche” and “Metal Finish-ing”)

In October 1986, at the V International Congress of Heat Treatment ofMaterials in Budapest, the name of the International Federation for HeatTreatment of Materials, by then in existence for over 10 years, was changed

to International Federation for Heat Treatment of Materials and SurfaceEngineering For obvious reasons, both the Federation as well as Congressesconvened under its auspices prefer mostly problems connected with heattreatment and, to a lesser degree, other problems connected with surface en-gineering

Over the past most recent years, many international conferences, ings and discussions devoted to surface engineering and its connectionswith other fields of science and technology were organized

meet-1)This term was later translated into French (l’ingenierie de surfaces), Russian (inzhinerya poverkhnosti), and German (Oberflächeningenierie) but to this day used in these languages

only sporadically.

1.2 Scope of topics forming the concept of surface engineering

Surface Engineering is almost as old as structural materials used by man.From the beginnings of time until the early 70s of our century, mankind hasworked on the development of surface engineering, although not aware ofthe concept The term of surface engineering, in use in the world for over tenyears, remained undefined and its topical scope is still the subject of discus-sions, especially on the aspect of definitions

In various ways, attempts have been made to define and to conduct abroader discussion of selected problems of surface engineering, especiallythose viewed through the techniques of formation covered by this scope[1, 4] Various book and handbook type publications presented different,chronologically older technologies, within the scope of surface engineering.There was a lack of publications dealing with the newest methods of manu-facturing

Earlier, generally the concept of surface enginnering was understood assolely different techniques of forming superficial layers prior to the begin-ning of service Nothing was said about the formation of superficial layersduring service, about research and propertiers or about modeling of theseproperties for concrete examples of application Even newer literature doesnot present a modern approach to the overall concept of surface engineering[5, 6]

Today, such narrow understanding of surface engineering does not fice In fact, this would be a far-reaching simplification For this reason, itwas broadened during the years 1993-1995 to include problems of utilization

suf-of superficial layers, as well as problems suf-of their design [3, 4]

Based on research conducted since the 80s, as well as available scientificand technical literature, the following topical scope and a definition of sur-face engineering are proposed:

Surface engineering is a discipline of science, encompassing:

1) manufacturing processes of surface layers, thus, in accordance with the accepted terminology - superficial layers and coatings, produced for both tech- nological and end use purposes,

2) connected phenomena,

3) performance effects obtained by them.

Surface engineering encompasses all scientific and technical problemsconnected with the manufacture of surface layers prior to end use orservice (technological layers) or during service (service-generated layers),

on or under the surface (superficial layers) or on a substrate (coatings),with properties differing from those of the material which may be intro-duced to the surface of the core in the form of gas, liquid or solid (Fig 1.1)

It also includes research of connected phenomena and of potential andusable properties of surface layers, as well as problems connected withlayer design