Showing papers in "Transactions of The Institute of Metal Finishing in 2009"
TL;DR: In this paper, the principles and applications of the PEO coating process are considered, including the fundamentals of oxide deposition, the technology involved and the typical characteristics of the coatings.
Abstract: The introduction of plasma electrolytic oxidation (PEO) as a surface finishing technique has enabled a range of hard, dense oxide coatings to be produced on aluminium, magnesium, titanium and other lightweight alloy substrates. As with all surface coating technologies, successful development of PEO coatings requires adequate attention to substrate pretreatment together with careful control of electrolyte conditions and process variables. The principles and applications of the PEO coating process are considered, including the fundamentals of oxide deposition, the technology involved and the typical characteristics of the coatings. Industrial applications are considered together with their coating requirements. Plasma electrolytic oxidation coating is a specialised but well developed process. Suitable control of electrolyte and process conditions can realise a novel range of coatings having technologically attractive physical and chemical properties. The development of PEO technology over the last decade has provided coatings having controlled appearance, hardness, corrosion resistance and other tribological properties across an extending range of industrial sectors. Continuing developments are concisely reviewed and the PEO process is illustrated by the characterisation of anodised coatings on an AZ91 magnesium alloy surface.
267 citations
TL;DR: In this paper, a systematic study into the electrolytic deposition of Zn metal from ionic liquids based on eutectic mixtures of choline chloride (ChCl) with either ethylene glycol (Eg) or urea was conducted.
Abstract: Reported here are results of a systematic study into the electrolytic deposition of Zn metal from ionic liquids based on eutectic mixtures of choline chloride (ChCl) with either ethylene glycol (Eg) or urea. Cyclic voltammetry and gravimetric acoustic impedance spectroscopy (EQCM) techniques have been used to probe mass-transfer and charge-transfer mechanisms. The results show that nucleation in the urea based liquid is fast but bulk growth is slow, whereas nucleation in the glycol based liquid is slow but bulk growth is relatively fast. Critical surface coverage necessary for the transition from nucleation to bulk growth is similar for both liquids. Additionally, ex situ atomic force microscopy (AFM) has been used to probe the morphology of the metallic deposit at two different potentials during a linear sweep voltammogram.
90 citations
TL;DR: In this article, the electrodeposition of microcrystalline iron from an ionic liquid composed of choline chloride, urea and FeCl3 was demonstrated, and the use of constant current plating technique was found to produce homogeneous, dense and grey matt iron deposits.
Abstract: The electrodeposition of microcrystalline iron from an ionic liquid composed of choline chloride, urea and FeCl3 is demonstrated. The use of constant current plating technique is found to produce homogeneous, dense and grey matt iron deposits. The deposited iron films exhibit good corrosion resistance. Pure iron layers of up to 10 μm could be readily produced from the selected iron (III) electrolyte system.
42 citations
TL;DR: In this article, the morphological and structural properties of the alloys were systematically studied using XRD and SEM techniques, and cyclic voltammetry of the individual metals was performed to understand the electroplating process of the films.
Abstract: Zn, Zn–Ni, Zn–Fe and Zn–Fe–Ni films have been deposited by electrochemical deposition technique onto steel plate substrates. The objective of this study was to characterise the corrosion properties of these alloys in saline solution for the application as new environmentally friendly sacrificial coatings in the protection of steel structures. The morphological and structural properties of the alloys were systematically studied using XRD and SEM techniques. Cyclic voltammetry of the individual metals was performed to help understand the electroplating process of the films. Grain sizes of the films were calculated using Scherrer's formula. Partial substitution of Zn to Fe and Ni leads to an improvement in the corrosion resistance. Compared with other zinc alloys, the Zn–Ni alloy deposit was the noblest.
31 citations
TL;DR: A new group of anodic materials and lead-cobalt-titanium alloys, produced in various ways, used as anodes for zinc electrowinning have been investigated in this article.
Abstract: A new group of anodic materials and lead–silver alloys, produced in various ways, used as anodes for zinc electrowinning have been investigated. The new anodic materials are composite coatings, deposited on lead–calcium rolled substrates, consisting of a lead matrix and a cobalt–titanium phase. The cobalt and titanium are present in the lead matrix as CoTiO3 nanoparticles. The behaviour of lead–cobalt–titanium anodes during zinc electrowinning was studied by means of galvanostatic polarisation investigations. The processes, occurring on the anodes during zinc electrowinning, have been studied by cyclic voltammetry. The surface morphology of the composite electrodes was investigated by scanning electron microscopy. It has been established that the anodic potentials of the composite electrodes investigated are negligibly higher than those of the classical lead–silver alloy. It has been shown by cyclic voltammetry that the curves of the new electrodes possess the same characteristic peaks as those of...
28 citations
TL;DR: In this paper, the corrosion resistance of electroless (EL) Ni-low B coatings, obtained using an alkaline borohydride-reduced electroless plating bath, with varying concentrations of NaBH4 (0·2−1·0 g L−1), in 3·5%NaCl, was evaluated.
Abstract: The corrosion resistance of electroless (EL) Ni–low B coatings, obtained using an alkaline borohydride-reduced electroless plating bath, with varying concentrations of NaBH4 (0·2–1·0 g L−1), in 3·5%NaCl, was evaluated. The rate of deposition, boron content and the size of the nodules of the EL Ni–low B coatings were increased while the crystallinity of the coating was decreased with increasing concentration of NaBH4. The change in chemical composition and decrease in crystallinity did not seem to have any influence on the corrosion resistance of the EL Ni–low B coatings of the present study, as opposed to the nodular growth with a columnar structure which had a profound effect. The results of polarisation and electrochemical impedance spectroscopy (EIS) studies confirm penetration of the corrosive medium through the columnar nature of the coating and ascertain its dominating influence on the corrosion resistance of EL Ni–low B coatings over other factors. The results of the present study again co...
23 citations
TL;DR: In this paper, the influence of additives (Cl−, thiourea and gelatine) and pulse plating parameters on the structure and properties of copper coatings obtained through an acid copper plating bath was investigated.
Abstract: In this study, the influence of additives (Cl−, thiourea and gelatine) and pulse plating parameters on the structure and properties of copper coatings obtained through an acid copper plating bath w...
22 citations
TL;DR: In this paper, the tribological properties of nanocrystalline nickel coatings were compared with those of conventional hard chromium coatings using the pulse electroplating technique, and the results showed that nanocrystine coatings (10 nm grain size) showed higher microhardness values than chromium coats.
Abstract: In this study, the tribological properties of nanocrystalline nickel coatings were compared with those of conventional hard chromium coatings. Nanocrystalline nickel coatings were synthesised in a Watt's bath using the pulse electroplating technique. Changes in the saccharin concentration in the Watt's bath were studied in order to develop superior properties for nanocrystalline nickel coatings relative to conventional chromium coatings which were electroplated galvanostatically. Wear resistance, microhardness, surface roughness and coefficient of friction were evaluated for both electrodeposits. Tribosurfaces were studied by scanning electron microscopy and energy dispersive X-ray analysis. X-ray diffraction patterns were used to determine the average grain size of nanocrystalline nickel coatings. Nanocrystalline nickel coatings (10 nm grain size) showed higher microhardness values than chromium coatings. Also, high saccharin concentration in the nickel bath resulted in nanocrystalline nickel coa...
18 citations
TL;DR: In this paper, it was shown that a specific anodic charge depending on the charge of the previous cathodic pulse is needed to obtain a crack free coating and that residual stress in the coating will be less at more frequent current reversals.
Abstract: It has for a long time been known that crack free chromium coatings can be obtained by pulse reversal plating, but it has only much later been understood that reoxidation of hydrogen from the surface during the anodic periods is essential for obtaining crack free deposits. In this paper, it is shown that a specific anodic charge depending on the charge of the previous cathodic pulse is needed to obtain a crack free coating and that residual stress in the coating will be less at more frequent current reversals. Furthermore, too large an anodic charge will result in redissolution of chromium and thereby decrease the current efficiency.
18 citations
TL;DR: In this article, the authors used gold deposits which are highly pure, dense, conductive, and smooth for high frequency optical devices, which operate at high frequencies and require gold-coated materials.
Abstract: Optoelectronic devices, which operate at high frequencies, require gold deposits which are highly pure, dense, conductive and smooth. Often devices as thick as 15 μm are needed, which is much thick...
17 citations
TL;DR: In this paper, an investigation of the microscopic Au electrodeposition dynamics is presented, where extensive sets of SERS spectra during prolonged potentiostatic electrodepositions (∼3 h) are recorded.
Abstract: A considerable amount of electrochemical and structural information is available on Au electrodeposition, but its dynamic aspects are still largely ignored. In this paper, an investigation of the microscopic Au electrodeposition dynamics is presented. Extensive sets of SERS spectra during prolonged potentiostatic electrodeposition (∼3 h) are recorded. Two different spot sizes have been used, in order to also obtain some information on the coupling of temporal and spatial fluctuations at the cathodic surface. The time evolution of the SERS background and the intensity of the stretching band of adsorbed CN− have been used as markers of surface morphology and chemistry respectively. Statistical analyses of these quantities allowed extraction of detailed information at the coupled dynamics of SERS enhancement and surface concentration of CN−. The spectroelectrochemical investigation is complemented by SEM observations and mathematical modelling of the coupled dynamics of cathode morphology and CN− sur...
TL;DR: In this article, the zinc-nickel electrodeposition was carried out in a sulphamate bath at pH 3-4 by pulse plating and the deposits obtained were characterised by measuring microhardness, surface roughness and by employing SEM, XRD, AFM techniques.
Abstract: In this study, zinc–nickel electrodeposition was carried out in a sulphamate bath at pH 3–4 by pulse plating and the deposits obtained were characterised by measuring microhardness, surface roughness and by employing SEM, XRD, AFM techniques. The corrosion behaviour of the deposits was evaluated by potentiodynamic polarisation. The deposits obtained by pulse plating have an increased Ni content, thought to be responsible for an improved corrosion resistance.
TL;DR: In this article, the applicability of UV irradiation for modification of the COP resin, avoiding the roughness of the surface, was investigated, and around 0·8 kN m −1 of peel strength between the deposited copper top layer and the COP substrate was obtained through applying the modification by UV irradiated and electroless Cu-Ni-P plating as a seed layer deposition on to the irradiated COP.
Abstract: Polytetrafluoroethylene is one of the leading candidates for a low dielectric constant material. The authors have studied metallisation by electroless deposition followed by electroplating on cycloolefin polymer (COP), an alternative material which has similar electrical characteristics to polytetrafluoroethylene. Conventionally, a microroughened surface has to be created by a strong etching medium in order to achieve a good adhesion between the deposited metal and insulating resin. However, this etched surface results in transmission loss due to the skin effect. Thus, the authors focussed on the applicability of UV irradiation for modification of the COP resin, avoiding the roughness of the surface. Around 0·8 kN m–1 of peel strength between the deposited copper top layer and the COP substrate was obtained through applying the modification by UV irradiation and electroless Cu–Ni–P plating as a seed layer deposition on to the irradiated COP. The insulation resistance using a comb pattern was also ...
TL;DR: Ni-TiO2 composite coatings were applied to sintered NdFeB permanent magnets by using a special pretreatment process and electrodeposition to increase corrosion resistance as discussed by the authors.
Abstract: Ni–TiO2 composite coatings were applied to sintered NdFeB permanent magnets by using a special pretreatment process and electrodeposition to increase corrosion resistance. Anatase (A) nano TiO2 particles and rutile (R) nano TiO2 particles were separately added to the Ni bath to fabricate the Ni–TiO2 composite coatings; for comparison, Ni-only coatings were also fabricated and assessed. X-ray diffraction and scanning electron microscopy were employed to examine the texture and the morphology of the coatings. Polarisation resistance tests show that the corrosion potential of Ni–TiO2 (A) composite coating is about 600 mV higher than that of the NdFeB substrate in 3·5 wt-% NaCl solution, and as a result the corrosion current density drops. Both SEM and electrochemical impedance spectroscopy tests indicate that Ni–TiO2 (A) composite coating is compact and can effectively protect the NdFeB substrate from corrosion.
TL;DR: In this article, the corrosion resistance of zinc-nickel alloy deposited from direct current deposition (DCD) has been compared with that of the deposit obtained by pulse current using the electrochemical impedance spectroscopy method.
Abstract: Zinc–nickel alloy was electrodeposited on stainless steel using pulse current deposition (PED) from a chloride–sulphate bath. Duty cycles were varied between 10 and 80% and frequency was changed from 10 to 100 Hz. The deposit characteristics were analysed using SEM, XRD and AFM and the results are presented in this paper. The corrosion resistance of zinc–nickel alloy deposited from direct current deposition (DCD) has been compared with that of the deposit obtained by pulse current using the electrochemical impedance spectroscopy method.
TL;DR: In this article, the semiadditive process has been used to produce fine pitch substrates of chip on film (COF) substrate, where the width of the conductor of the substrate is usually smaller than 50 μm with the smallest ones being 15 μm.
Abstract: On the chip on film (COF) substrate, the width of the conductor of the substrate is usually smaller than 50 μm, with the smallest ones being 15 μm. It is difficult to produce it by the conventional subtractive process. In this study, the semiadditive process has been used to produce fine pitch substrates of COF. The flexible copper clad laminate (FCCL) used in the semiadditive process is a copper foil that is 2 μm thick; the FCCL with 8 μm thick copper foil is used to produce the same substrate of a COF by the conventional subtractive process. The effects of the semiadditive process and subtractive process have been studied and compared. Two sample substrates (50 μm/50 μm and 30 μm/30 μm fine pitch) have been designed. H2SO4/H2O2 etchant has been used in the etching process for the semiadditive process successfully. The test results of the metallographic slicing tester and the SEM show that the semiadditive process is more suitable to produce fine pitch pattern (below 50 μm/50 μm) than the subtrac...
TL;DR: In this article, the effect of current density and SiC concentration on the weight percentage of embedded particles was determined, and the incorporation of SiC within the alloy matrix resulted in the improvement of the microhardness of the deposits.
Abstract: Ni–Co/SiC composite coatings were produced by electrodeposition from a Watt's-type bath. The effect of current density and SiC concentration on the weight percentage of embedded particles was determined. Enhanced SiC incorporation was observed in the presence of small amount of cesium ions in the plating bath. It was attributed to increased adsorption of Co2+ and Ni2+ on the particles induced by Cs+ ions. Preferential adsorption of Cs+ was also observed. Validation of the Guglielmi model was confirmed for the codeposition process in the Ni–Co/SiC system. The incorporation of SiC within the alloy matrix resulted in the improvement of the microhardness of the deposits. Morphology and particle distribution in the deposits was studied by optical and electron (SEM, TEM) microscopy.
TL;DR: In this article, the corrosion and electrochemical behaviour of pulse plated Zn-Fe group metal alloy deposits obtained from chloride bath have been studied as a function of pulse parameters such as duty cycle, frequency and average current density.
Abstract: The corrosion and electrochemical behaviour of pulse plated Zn–Fe group metal alloy deposits obtained from chloride bath have been studied as a function of pulse parameters such as duty cycle, frequency and average current density. The frequencies of electric current, T on, T off, pulse duty cycles have large effects on the chemical composition and surface morphology of the deposits. Results of the electrochemical tests indicate that the corrosion resistance of pulse plated Zn–Fe group metal alloy coatings is superior to that of the alloy deposited by the direct current technique. The on time and off time had no significant influence on the deposit characteristics. Characterisations of deposits were carried out by cyclic voltammetry and the surface morphology was studied by scanning electron microscopy. The composition of the alloy deposits were analysed by spectrophotometry. Refinements in grain size and deposit composition have been made for better corrosion performance with the advent of pulse...
TL;DR: In this paper, the influence of ammonium selenate and thiourea (AS-TU, 0·5 g L−1) on electrodeposition of Zn-Mn alloy coatings from sulphate-citrate bath (SCB) has been studied.
Abstract: The influence of thiourea (TU, 0·5 g L−1) and additive mixture of ammonium selenate and thiourea (AS–TU, 0·5 g L−1) on electrodeposition of Zn–Mn alloy coatings from sulphate–citrate bath (SCB) has been studied. Investigations of alloy composition were carried out by atomic absorption spectroscopy and inductively coupled plasma. A profile of the relative concentration of sulphur was obtained using glow discharge spectroscopy. The morphology of the coatings was studied by scanning electron microscopy. The crystal structure was investigated by X-ray diffraction. Two phases (metastable ϵ and β) were detected in coatings electrodeposited from SCB with TU and mixture of AS–TU at j c≥10 A dm−2 (≥50%Mn). Zn–Mn alloy coatings, electrodeposited from an SCB with 0·5 g L−1 TU were harder than coatings electrodeposited from SCB with AS alone, and a mixture of AS–TU. Coatings electrodeposited from SCB with a mixture of AS–TU had the lowest tensile stress.
TL;DR: In this paper, the possibilities of producing a wear and corrosion resistant nanocrystalline composite coatings with a nickel matrix have been investigated, and a Watts type nickel plating bath with low concentration of nickel ions (0·75 mol dm-3), organic addition agents and boron as dispersed particles were used for deposition of the nanocrystine composite electrochemical coatings.
Abstract: The possibilities of producing a wear and corrosion resistant nanocrystalline composite coatings with a nickel matrix have been investigated. A Watts type nickel plating bath with low concentration of nickel ions (0·75 mol dm–3), organic addition agents and boron as dispersed particles were used for deposition of the nanocrystalline composite electrochemical coatings. The crystalline growth and preferred orientation of the prepared deposits were studied by X-ray analysis. The content of particles in coatings was examined gravimetrically. The roughness, microhardness and the wear of the coatings Ni–B were measured. Voltammetry was used for examination of the corrosion resistance of samples of composite coatings in 0·5M NaCl. The results suggest that the effect used of the organic compounds was the development of the nanostructure of the nickel matrix. The wear resistance increased with increasing microhardness of deposits. Strengthening the nanocrystalline nickel matrix with boron particles gave a ...
TL;DR: In this article, the authors studied the problem of reducing electrical power consumption in electroplating processes and found that small gains can be achieved by optimising solution concentrations, but greater gains are attainable by the use of air-free agitation.
Abstract: If electroplating processes are to be
truly ‘green’ a number of issues must be
addressed, notably water and electrical
power usage. Electricity is used both for
the driving of the process itself and for
some of the process conditions, eg.
temperature, agitation etc. The study of
solution conductivity for electroplating
solutions shows how some electrical
power saving can be achieved. In the
case of nickel small gains can be made
by optimising solution concentrations
but greater gains are attainable by the
use of air-free agitation.
TL;DR: In this paper, several electrolytes from which it is possible to deposit nickel-cobalt alloys with high hardness (>550 HV), low internal stress and easy maintenance were investigated.
Abstract: Electroforming, as a versatile process for fabrication of durable tools, is experiencing an increasing interest with the start of commercial use of products with micro or nanofeatures. Electroformed tools can be utilised for polymer, glass and metal replication processes and, in addition, when extreme demands, in terms of tool accuracy, process temperature and tool wear, are requested. In order to meet these demands, electroforming of hard nickel alloys is an obvious way forward. This paper presents several electrolytes from which it is possible to deposit nickel–cobalt alloys with high hardness (>550 HV), low internal stress and easy maintenance. Moreover, different organic complexing agents – as well as alternatives to boric acid – have been investigated.
TL;DR: In this paper, the effect of single pulses within a pulse sequence can be calculated stepwise in high precision, taking into account the change of the substrate surface and geometry after each pulse step.
Abstract: The development of any pulse sequence is a highly knowledge based process. Beside the knowledge of electrochemical electrolyte properties, the tailoring of the actual field line distribution and the local surface potentials via the applied pulse sequence is the main focus of the scientific development. The combination of pulse plating and numerical simulation offers a very high success rate for definition of pulse plating processes. Simulation tools are the only option to study current distribution and potential fields and are applicable for any possible electrolyte system and cell geometry. For developing a pulse plating sequence it is of major importance that the effect of single pulses within a pulse sequence can be calculated stepwise in high precision, taking into account the change of the substrate surface and geometry after each pulse step. Only in this way can the exact influence of cathodic and anodic pulse steps be retrieved. Additionally, the consideration of shieldings and cell geomet...
TL;DR: In this paper, anodic alumina films containing polyaniline and TiO2 or ZrO2 nanoparticles were electrochemically synthesized on an AA2024T3 aluminium alloy in a single step anodising process carried out in oxalic acid electrolyte containing anilines and nanoparticles.
Abstract: Anodic alumina films containing polyaniline and TiO2 or ZrO2 nanoparticles were electrochemically synthesised on an AA2024T3 aluminium alloy in a single step anodising process carried out in oxalic acid electrolyte containing aniline and nanoparticles. The morphology and composition of the films were examined by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The resultant coatings, with a thickness of ∼2·5 μm, presented a polyaniline and nanoparticle rich layer in the near surface region, with a thickness in the range of 150–250 nm. The electrochemical polarisation curves revealed that the TiO2 containing films provide improved corrosion protection to the AA2024T3 aluminium alloy, showing a passive current density two orders of magnitude lower than the films with ZrO2 nanoparticles and the films without nanoparticles. The improved corrosion protection offered by the TiO2 nanoparticle containing coatings is attributed to the presence of the nanoparticle...
TL;DR: The occurrence of zinc whisker growth following the heat treatment of bright acid zinc electroplated steel has been reported in this paper, where the effect of such growth under chromate conversion coatings, applied to zinc surfaces for increased corrosion performance, was also studied.
Abstract: The occurrence of zinc whisker growth following the heat treatment of bright acid zinc electroplated steel has been reported in this study. The effects of such whisker growth beneath chromate conversion coatings, applied to zinc surfaces for increased corrosion performance, were also studied. In this investigation, field emission gun scanning electron microscopy (FEGSEM) showed that bright acid zinc electroplated steel exposed at 150°C for 1 h promoted zinc whisker growth. Furthermore, the whiskers were able to penetrate chromate conversion coatings. Cross-sectional images of a protruding zinc whisker associated feature, using focused ion beam (FIB) electron microscopy, did not establish a clear grain pattern within the subject or surrounding electrodeposit.
TL;DR: In this paper, the properties of soft magnetic NiFe and NiCoFe coatings electrodeposited in the presence of saccharin and sodium lauryl sulphate additives were studied.
Abstract: The codeposition behaviour of the electrodeposited iron group alloy system, NiFe and NiCoFe, was studied in acid sulphate electrolyte. X-ray diffraction measurements revealed the existence of FCC phases. X-ray fluorescence analysis of the elemental composition in NiFe and NiCoFe coatings electrodeposited over copper substrate was also carried out. The result suggested that Ni is inhibited by the presence of Fe2+ and Co2+ ions. The properties of soft magnetic NiFe and NiCoFe coatings electrodeposited in the presence of saccharin and sodium lauryl sulphate additives were studied. Corrosion performance of these coatings in 3·5% NaCl solution was evaluated using impedance electrochemical techniques. The superior coefficient of friction of NiFeCo coatings was observed from block-on ring test.
TL;DR: A combination of plating technology and photolithography has long been applied for the preparation of minute metallic structures, for example the metal stamper for replication of master discs as discussed by the authors, which exhibits a highly precise traceability even with shapes in submicrometre order.
Abstract: A combination of plating technology and photolithography has long been applied for the preparation of minute metallic structures, for example the metal stamper for replication of master discs. This replication technique exhibits a highly precise traceability even with shapes in submicrometre order. Microelectro mechanical systems (MEMS) are expected to progress and the field requires minute metal components. In particular, three-dimensional metal components are greatly in demand. In the conventional process, however, a two-dimensional developed image of thick photoresist is formed to increase the height of the structure. In other words, it allows industry to merely form so called '2·5-dimensional (pseudo 3D) structure'. Consequently, it is difficult and/or impossible to fabricate a metal structure with variation in the horizontal direction such as overhangs. Recently, the formation method of multilayered photoresist moulds has been reported. This technique enables the formation of the stacked phot...
TL;DR: In this paper, the influence of frequencies of periodic reverse current on the quality of pigmented aluminium finishes has been studied, where pigmentation was achieved by electrolytic colouring with the use of alternating and periodic reverse currents (AC and PRC).
Abstract: The influence of frequencies of periodic reverse current on the quality of pigmented aluminium finishes has been studied. Pigmentation was realised by electrolytic colouring with the use of alternating and periodic reverse current (AC and PRC). The applied pigmentation nickel based electrolytes were prepared with and without the use of a complexing agent. Parameters of colour space were measured by spectrocolorimetry. Stripping was carried out in chrome–phosphorous acid to remove the coating of aluminium oxide prepared by anodic oxidation on aluminium. The content of nickel on the treated surface was determined by AAS and XRF analysis and the morphology of the stripped surface was investigated by SEM. A frequency of 50 Hz provided the high quality of the pigmented finishes under the test conditions for electrolytes containing a complexing agent. A frequency of 30 Hz was found to be suitable for pigmentation with electrolytes containing no complexing agent. The results for electrolytes without a co...
TL;DR: In this paper, a number of novel cleaning solutions have been investigated to address the challenging problem of how to remove fully crosslinked epoxide resins from RTM surface, which may compromise its reuse.
Abstract: Cleaning of RTM moulds – the
problem!
The removal of loosely bound or weakly
adsorbed contamination from surfaces
can usually be achieved using
conventional cleaning methods such as
solvents or proprietory aqueous-based
cleaning solutions. However, the
removal of fully crosslinked material
which might be strongly adsorbed or
chemisorbed onto surfaces, such as
paints or adhesives, presents a much
greater challenge. Similarly, residual
epoxide resins remaining on the inside
surfaces of resin transfer mould (RTM)
tooling post curing are strongly adhered
to the mould surface and need to be
removed so that the mould can be reused.
The mould materials are typically
steel or nickel but may be compositebased.
Conventional methods cannot
fully remove residual epoxide material
without the use of hazardous chemicals
and mechanical removal can easily
result in damage to the underlying
mould which may compromise its
reuse. Therefore, a number of
novel cleaning solutions have been
investigated to address the challenging
problem of how to remove fully
crosslinked epoxide resins from RTM
mould surfaces.
TL;DR: In this paper, the authors describe how surface and near surface analysis techniques are used to characterise thin films, providing suitable information for development, quality assurance and failure analysis for surface engineered thin films.
Abstract: Surface engineered thin films have a great commercial importance in a wide range of applications including precision engineering, data storage, microelectronics, automotive and many others. Regardless of the techniques used to fabricate the films, there is a need to analyse and characterise them to ensure that they will meet performance specifications. This review paper describes how surface and near surface analysis techniques are used to characterise thin films, providing suitable information for development, quality assurance and failure analysis. Quantification is frequently a challenge and various approaches are discussed.