Application of electrochemical techniques to organic coatings (AETOC 2011)

Abstract

AETOC 2011 took place in Mons, Belgium from 13–16, April 2011. This was the latest in a sequence of biannual meetings which have taken place since 1999. The meeting falls under the auspices of the European Federation of Corrosion Coatings Working Party and was the eighth international workshop in the series. Previous meetings have been held in Genoa, Italy in 1984; Schliffkopf in the Black Forest, Germany in 1999; Jurata, near Gdansk in Poland, in 2001; at Sintra near Lisbon, Portugal in 2003; at Villard de Lans near Grenoble, France in 2005; at Baiona in Northern Spain in 2007 and at Grado, Northern Italy in 2009 (reports on several of them can be found in previous issues of CEST or its predecessor British Corrosion Journal).     

IFHTSE 19th Congress

Abstract

The 19th Congress of the International Federation for Heat Treatment and Surface Engineering was held at the Grand Central Hotel, Glasgow, Scotland on 17–20 October 2011. In addition to participants from UK companies and universities, a further 29 countries were represented in the attendance list: Algeria, Austria, Belgium, Brazil, China, Croatia, Czech Republic, Denmark, Egypt, Estonia, France, Germany, Hungary, India, Iran, Italy, Japan, Kazakhstan, Korea, Mexico, Poland, Romania, Russia, Slovenia, Spain, Sweden, Switzerland, Thailand, and the USA.     

Eurocorr 2011: ‘Developing solutions for the global challenge’ - part 1

Abstract

This year’s Eurocorr conference took place at the International Fairs, in Stockholm from 4th to 8th September 2011. The focus of the meeting was ‘Developing solutions for the global challenge’. The meeting attracted over 800 delegates and over 300 papers and 130 posters were presented during the 28 sessions and workshops. Parts 1–5 will review the technical sessions over five issues with the opening and plenary lectures and technical sessions on coatings, environmentally assisted cracking and nuclear corrosion covered in this report.     

Industrial treatment processes for recycling of green foundry sands

Abstract

Three treatment processes for the reclamation of green moulding sands coming out from a cast iron foundry located in Northern Italy are considered in this study. A wet mechanical treatment, a dry mechanical treatment and a dry mechanical plus heat treatment are compared to evaluate the efficiency of each process and to point out the best regeneration solution for the recycling of reclaimed sand in foundry operations. The inflow and the outflow samples of each process were characterised by means of particle size analysis and the determination of silica, loss on ignition, acid request, oolitic and some metals contents. A final evaluation of the three processes was performed taking into account the obtained quality of recovered silica sand and the economical aspects; the wet mechanical and the dry mechanical plus thermal treatments are most effective for the recovery of green moulding sands coming out from the considered foundry plant for cold box core production.     

Corrosion. A Literature Review

Abstract

Introduction: In contrast to the situation in 1962 and 1963, when, in all, there were seven major international meetings dealing in whole or in part with the subject of corrosion, the year 1964 has seemed to be relatively quiet, at least in so far as interchange of experience and views upon theoretical aspects are concerned. In 1964, there was in fact only one major international meeting—the First European Congress on Marine Corrosion and Fouling, held in Cannes in June.     

Eurocorr 2014: ‘Improving materials durability’ – part 3

Abstract

The 2014 Eurocorr meeting was held at the Palazzo dei Congressi in Pisa, Italy from 8 ??12^th September 2014. The focus of the meeting was improving materials durability – from cultural heritage to industrial application. The meeting attracted over 948 delegates from 58 countries with Italy, France and Germany and the UK providing around half the delegates between them. Over 440 papers and 20 posters were presented during the 18 sessions and 5 workshops. Parts 1 – 4 of this report will review the technical sessions over four issues with marine corrosion, corrosion in oil and gas production, corrosion in the refinery industry, cathodic protection, corrosion in drinking water and drinking water systems, and corrosion of archaeological and heritage artefacts covered in this report.     

Some Effects Arising From the Presence of Copper in Boilers During Chemical Cleaning

Abstract

It is suggested that during the process of the chemical cleaning of boilers with restrained acid, enhanced attack upon the steel may take place if significant quantities of copper are present. Laboratory experiments simulating this process have given similar corrosion results whether the copper is deposted from solution or derived from the steel, having been concentrated at the oxide-metal interface during heat treatment. It is suggested that the proprietary restrainer used in the present work was preferentially adsorbed on the copper leaving the steel unprotected.     

Mechanised welding of tubes to tubeplates

Abstract

With the introduction of the Ministerial Decree of 24 November 1984, which allows the use of polyethylene in the construction of underground pipelines for gas transportation, the said material and the relevant tvelding techniques have undergone considerable development in Italy.

This paper describes the main characteristics of this unusual plastic and indicates the welding processes normally used for joining P E pipes and fittings.

The accent is placed on the present possibilities of destructive and non-destructive testing of the welded joints, and an outline is given of the new Italian plan for the qualification of welders of polyethylene, prepared by UNIPLAST in conjunction with the Italian Welding Institute.     

The influence of different locations on copper corrosion with different external electric fields under a chloride-containing thin electrolyte layer

ABSTRACT

The influence of different locations on copper corrosion with different external electric fields under a chloride-containing thin electrolyte layer was studied using polarisation curve measurement and surface analysis techniques. The results indicated that, under an external direct current electric field, the anodic current densities near the positive plate were smaller than that near the negative plate, while the cathodic current densities near the positive plate were larger than that near the negative plate. However, at different locations in an external alternating current electric field, the anodic current densities were little change, while the cathodic current densities were obviously different.     

Principles of robotics: regulating robots in the real world

ABSTRACT

This paper proposes a set of five ethical principles, together with seven high-level messages, as a basis for responsible robotics. The Principles of Robotics were drafted in 2010 and published online in 2011. Since then the principles have influenced, and continue to influence, a number of initiatives in robot ethics but have not, to date, been formally published. This paper remedies that omission.     

Synopses of Papers

Abstract

This review examines the electrochemical methods available to corrosion scientists today and developments that have taken place in the past 25 years. The fundamental principles of the methods are outlined and some practical difficulties explained.     

Interfacial Corrosion of Brazed Stainless Steel Joints in Domestic Tap Water. II. Metallographic aspects

Abstract

Previous work has indicated that interfacial corrosion of brazed stainless steel joints in domestic tap water is probably associated with a selective dissolution of one component of a lamellar eutectic structure, which thereby provides easy access to the interface for the aqueous environment.

The metallographic features of the phenomenon have now been explored in more detail in order to characterise the structural changes taking place. A tentative mechanism is proposed to explain the changes observed at the interface where copper is found to be deposited.     

High-energy NdFeB magnets and their applications

In sintered NdFeB magnets, additive elements for increasing coercivity decrease residual magnetization. Also, fine magnetic powder oxidization prevents identification of the stoichiometry composition (Nd ₂Fei₁₄B).To improve the magnetic properties of a sintered NdFeB magnet, the authors have developed a method involving two alloys. Magnetic Nd ₂Fei₁₄Balloy and a rare- earth- rich alloy (including richer dysprosium content) are melted individually and mixed together after coarse pulverization. After the sintering process, dysprosium in the sintered body is enriched in each grain region near the grain boundary. The two- alloy method minimizes the liquid phase necessary to keep the coercive force at a useful level, and thus results in compositions closer to stoichiometry. The energy product of magnets having an inhomogeneous dysprosium distribution is typically 360 kj - m ^{- 3} (45 MG.Oe) at production level. The corrosion characteristics of cobalt- substituted NdFeB magnets also were investigated. These magnets are now used in voice coil motors for hard disk drives and contribute to shortening access time and hard- drive downsizing.     

Microstructure of cobalt based alloy coatings produced by laser deposit welding

Abstract

Coatings of cobalt based alloy HMSP 2528, deposited on a nickel based superalloy using a transverse flow CO₂ laser, are investigated. Sections of the coatings have been examined to reveal their microstructure and phase composition using an Olympus PME–3 type optical microscope, scanning electron microscope, transmission electron microscope, and X-ray diffractometer. The results showed that primary phase (γ-Co) and eutectic (γ-Co + Cr₂₃C₆) were present in the coatings. Rapid directional solidification was found at the interface, where the growth direction was perpendicular to the interface. Multidirectional growth and growth parallel to the scanning direction were also found in the central region and near the top surface, respectively. At the remelted boundary between two tracks, a novel microstructure was found in which the crystallisation direction of the first track was transmitted to the second track. As more tracks were deposited, coarsening dendrites could be found at the interfaces.     

Forthcoming corrosion events

Abstract

The XX International Materials Research Congress (IMRC) 2011 was held during August in the tropical paradise of Cancun, in the Yucatan peninsula, Mexico. This is a joint event sponsored by the Sociedad Mexicana de Materiales (MRS-Mexico) and the Materials Research Society (MRS-USA).     

Survey of the Scientific,Technical and Educational Activities in the Field of Corrosion of the Member Countries of the European Federation of Corrosion in 1976

Abstract

This report gives a survey of the activities in the field of corrosion in 1976 of Belgium, France, Germany, Hungary, Italy, the Netherlands, the Scandinavian countries, Switzerland and the UK. The material is classified under: Corrosion properties of metals, corrosive media, types of corrosion, corrosion prevention, special applications, test and measurement technology, information and education, economic aspects.     

Chemical and structural properties of ancient metallic artefacts: multitechnique approach to study of early bronzes

Abstract

The results are presented of a characterisation study of the microstructure and microchemistry of archaeological bronze (Cu–Sn) artefacts from the eighth to the sixth century bc. Metallographic examination, with optical and electron optical microscopy, has been performed on polished sections of early Iron Age studs and bracelets found in incineration tombs of the Necropolis of Chiavari in Italy. A heterogeneous microstructure of the bronze was observed, exhibiting a wide range of grain sizes, and a predominant α-phase solid solution containing α/δ and α/? eutectoid phases decorated with a high density of inclusions. The composition of grain boundary surfaces was determined, using scanning Auger microscopy (SAM), on specimens fractured in vacuo. The extent of tin segregation at the grain boundaries was 3–5 times greater than that in the grain interiors. Copper rich sulphides occasionally containing the oligoelements (iron and lead) were identified as the predominant type of inclusions formed at the grain interfaces and within the grains. Analysis of the corrosion patina at the surface of the bronze artefacts was conducted by combining X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, and SAM. The patina was found to exhibit a multilayered structure and a complex chemical composition forming various crystallographic phases including malachite, cuprite, and copper–tin oxide. Corrosion of the underlying bronze matrix proceeded along the grain boundaries, where the sacrificial corrosion of tin reacting with diffused oxygen and chlorine was identified. The results of this study have been used to clarify the metallurgy and manufacturing processes of the examined finds, and to evaluate the state of their degradation.     

Rendezvous Hong Kong

Abstract

The inaugural meeting of the IMF's Hong Kong branch took place on the evening of Friday 24 March 2006. A dozen local members gathered at the Clifton Centre in the Central district. We were also pleased to welcome several invited guests, including Fred Yeung representing the Hong Kong Metal Finishing Society.     

Chemical vapor deposited diamond for thermal management

The record-high thermal conductivity of high-quality diamond makes it a natural choice for many applications in thermal management. The columnar microstructure of chemical-vapor-deposited diamond thick films, however, causes anisotropy and a strong gradient in the conductivity, both of which can be understood in terms of phonon-scattering defects that aggregate near grain boundaries. Techniques to take maximum advantage of the high thermal conductivity include the removal of fine-grained low-conductivity material near the substrate surface and the provision of excellent thermal contact between the diamond and heat sources or sinks. J.E. Graebner earned his Ph.D in physics at Northwestern University in 1967. He is a member of the technical staff at Bell Laboratories, Lucent Technologies. S. Jin earned his Ph.D in materials science at the University of California at Berkeley in 1974. He is currently technical manager at Bell Laboratories, Lucent Technologies. Dr. Jin is also a member of TMS.     

氧化铝基复合陶瓷-金属钎焊界面的热应力

用Ag-Cu-Ti钎料钎焊SiCw／Al2O3复合陶瓷和金属时，陶瓷与钎料发生化学反应，在陶瓷表面形成由TiO、TiC等物相组成的反应层。采用有限元法，对SiCw／Al2O3复合陶瓷／反应层界面的热应力进行了计算。结果表明，复合陶瓷／反应层界面的残余应力变化急剧，最大拉应力位于晶须、基体和反应层交界处；晶须内部及其表面存在较高的双向压应力，Al2O3基体主要承受垂直于界面的拉应力；SiC晶须／反应层界面及其附近的反应产物TiC内具有较高的平行于界面的拉应力，当连接界面承受剪力作用时，SiC晶须／反应层界面和TiC处极易破坏。借助TEM和SEM观察了复合陶瓷／反应层界面区的精细结构和剪切断口形貌，并利用计算结果对观察到的现象进行了分析。