Progress of electroless amorphous and nanoalloy deposition: a review – Part 1

Abstract

The progress and longitudinal history of electroless plating from its discovery to its present development, from published research reports and, particularly, patents are discussed and reviewed in this paper. The progress of electroless plating can be divided into five stages: the discovery of electroless plating; the early stage of development; the period of slow growth; the period of rapid development; and the period of deeper, more fundamental development and nanoelectroless plating. The contents of each stage are described and discussed in detail. Investigating and understanding the history of electroless plating can not only make clearer the process of development and characteristics of electroless plating, but also clarify to some degree the scientific and technical direction of the process and its applications. In the current Part 1, the authors review the first three stages noted above and some details from the period of fast development including the wealth of information gathered from numerous studies on the properties of electroless deposits. Part 2, to be published in a forthcoming issue of Transactions, will deal with further studies from the period of rapid development, including large scale applications, ternary and multicomponent alloys and composites, the impressive developments in China, now the world’s biggest market in electroless nickel plating, and development of electroless Fe–B alloy plating, again much of which took place in Chinese laboratories. In addition, in Part 2, the authors will discuss what they consider to be a period of sustained deep and fundamental research into the theory and mechanism of electroless plating, and development of nanoelectroless plating.     

IFHTSE Global 21: heat treatment and surface engineering in the twenty-first century Part 19 – Type I quenchants for quenching of aluminium: a review

Abstract

Some aluminium forgings and castings are cold water quenched in order to achieve the desired design minimum physical properties. When unacceptable distortion or cracking is encountered, hot water has traditionally been specified as an alternative quenchant. However, hot water quenching typically results in a significant loss of mechanical properties and a significant increase in the potential for intergranular corrosion. Approximately 30 years ago, SAE designated Type I poly(alkyleneglycol) copolymer quenchants were introduced as an alternative to hot water. These quenchants offered significant, often dramatic, advantages in residual stress and distortion reduction while still achieving the Mil-Handbook 5 design minimum properties. However, even though these quenchants have been available for such a long time, there is still wide spread misunderstanding regarding how they work, when they should be used and how they should be monitored. The objective of this paper is to address these issues.     

Progress of electroless amorphous and nano alloy deposition: a review – Part 2

The second part of this review of developments over the life span of electroless plating continues with the period of rapid development (1980–99), describing the upsurge of large scale application, research into ternary and multi-component alloys and composites, the rapid development in China – now the world’s biggest consumer of electroless Ni – and the development of electroless deposition of Fe–B based alloys. Since the new millennium began many fundamental mechanistic studies have been conducted and the development of nano-electroless plating has occurred.     

Surface characterization methods— XPS,TOF-SIMS, and SAM a complimentary ensemble of tools

X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and scanning auger microscopy (SAM) analytical techniques have played important roles in the characterization of the surface and the interfacial chemistry governing properties and performance of materials, and material interfaces. These techniques afford spatially resolved elemental and molecular analysis of the topmost atomic layers of solid surfaces and interfaces. Currently available instrumentation provides qualitative/quantitative analysis on molecularly complex materials with detection limits in the parts-per-billion (ppb) range and spatial resolutions approaching 30 nm. Each technique is unique in the information attained, therefore necessitating a multitechnique approach to achieve a complete surface characterization. Examples of coating/interfacial characterization by XPS, TOF-SIMS, and SAM are presented illustrating the functionality of these tools and the complimentary natures of them.     

Review on Cold Spray Process and Technology: Part I—Intellectual Property

The number of research papers as well as of patents and patent applications on cold spray and cold spray related technologies has grown exponentially in the current decade. This rapid growth of activity brought a tremendous amount of information on this technology in a short period of time. The main motivation for this review is to summarize the rapidly expanding common knowledge on cold spray to help researchers and engineers already or soon to be involved for their future endeavors with this new technology. Cold spray is one of the various names for describing an all-solid-state coating process that uses a high-speed gas jet to accelerate powder particles toward a substrate where they plastically deform and consolidate upon impact. Cold gas dynamic spray, cold spray, kinetic spray, supersonic particle deposition, dynamic metallization or kinetic metallization are all terminologies found in the literature that designate the above-defined coating process. This review on cold spray technology is divided into two parts. In this article, Part I, patents and patent applications related to this process are reviewed, starting from the first few mentions of the idea at the beginning of the 20th century to its practical discovery in Russia in the 1980s and its subsequent occidental development and commercialization. The patent review encompasses Russian and USA patents and patent applications. Part II will review the scientific literature giving a general perspective of the current understanding and capability of this process.     

Metallurgy and processing of coloured gold intermetallics — Part I: Properties and surface processing

Blue and purple gold alloys form in the alloying systems of gold with gallium/indium and aluminium respectively and are known to be very brittle and to possess low corrosion resistance. Taking into account these drawbacks this paper describes the results of a European funded research project. The properties of the blue and purple gold alloys and coatings such as corrosion resistance, metal release rates, hardness and colour and the influence of alloying additions on these properties are presented and discussed. Surface engineering techniques and investment casting were used for manufacturing of jewellery items with selectively coated coloured surface. Coatings of AuGa₂ and AuIn₂ blue gold alloys were applied on 18kt gold and Sterling silver jewellery by electroplating, laser/torch cladding or dipping into liquid gallium. The suitability of blue gold coatings for jewellery purposes will be discussed in the light of reliability and feasibility. The work consists of two parts. Part I describes properties and surface processing techniques while Part II deals with investment casting and related alloy design of coloured gold alloys.     

High speed temperature measurement in gear hobbing: Part I—design,concept and physical operation mode of the infrared-camera

Gear hobbing is the major technology to manufacture external gears. The motions of the tool and workpiece are dynamically linked. Therefore it is difficult to apply external measurement devices in the process. Especially the temperature, which is a vital factor to determine the load on the cutting edge, cannot be measured as easy as in other processes (for example turning). Suitable infrared-cameras are not commercially available, because these do not meet the demands for temporal and geometrical resolutions. Furthermore, commercial equipment has to be calibrated for each individual temperature (above 350 °C). This forced the Institute of Manufacturing Technology and Quality Management to develop an own measuring device. This camera is able to measure the temperature of the cutting surface within the gear hobbing process. Despite focusing the usage of the camera on hobbing in this paper, it can also be used to monitor further highly dynamical machining processes with discontinuous cutting conditions. This paper is divided into two parts. The first part describes the set-up, the concept and the physical and optical basics of the IR-camera. In the second part, the experimental realisation and the results of trials during an analogy test of the hobbing process are presented.     

Flattening of droplets and formation of splats in thermal spraying: A review of recent work—Part 1

Properties of the coatings developed during thermal spraying are essentially determined by rapid solidification of splats formed as a result of impingement of the melted powder particles onto a substrate surface. The processes of flattening droplets and formation of splats in thermal spraying have been studied intensively during the last two decades. The last review on this topic was published at the end of 1994. Since then many papers have been dedicated to investigating splat formation, taking into account such important issues as roughness of the substrate surface, wetting phenomena, and splashing. This review, consisting of two parts, includes the main results obtained since 1994 and examines the influence of solidification of the lower part of the splat, substrate roughness, wetting at the substrate-coating interface, substrate deformation, oxidation, and splashing on the dynamics of flattening of droplets and the formation of splats. Flattening of composite powder particles, splat-substrate interaction, and development of splat-substrate adhesion and splat porosity are discussed. Part 1 of the review covers the following issues, which significantly influence the droplet flattening and splat formation: droplet solidification during flattening and roughness of the substrate surface, composite morphology of the powder particles, and oxidation processes. The results provide a better understanding of the thermal spray processes to increase their efficiency.     

Oxidation of metals and alloys in gases—Literature review

Abstract

In previous reviews an attempt has been made to cover the whole corrosion field for the year in question. However, because of the difficulty of giving a balanced appraisal of progress over such a wide area, the present review and future reports will cover selected fields for the preceding five years. The first of the new series is concerned with the reactions between metals, alloys or coatings and gaseous environments, particularly at elevated temperatures.     

Polytypic transformations of the HfCr2 Laves phase – Part I: Structural evolution as a function of temperature,time and composition

HfCr₂-Laves phase alloys of different composition have been produced by arc-melting followed by homogenization by annealing at temperatures at which the C14-high temperature modification is stable. Polytypic phase transformations have been induced by subsequent annealing at different, lower temperatures for various times. The resulting (micro-) structure of the Laves phase has been characterized by X-ray powder diffraction (XRPD) and high-resolution transmission electron microscopy (HRTEM). At temperatures between 1300 °C and 1225 °C, a microstructure forms, which can be regarded as composed of randomly alternating C36 and C15 lamellae. At lower annealing temperatures (1050 °C-1150 °C), the C36 stacking sequences do not occur. Instead a lamellar C14/C15 microstructure develops, representing an incomplete C14 → C15 transformation. A phase map for the Laves-phase part of the Hf-Cr system has been constructed. The XRPD patterns are not a superposition of the diffraction patterns corresponding to the different occurring Laves-phase polytypes; instead a common, average diffraction pattern can be discerned which can be ascribed to coherent diffraction of the polytypes constituting the lamellar microstructure. This coherent diffraction by the irregular layer-stacking sequence induces broadening of the reflections corresponding to the specific polytypes, whereas the “fundamental” reflections, occurring for all polytypes, remain unbroadened. From the diffraction patterns two scalar parameters can be obtained, which describe the stage of phase transformation: one based on the intensity of a selected polytype reflection and the other one based on the average unit cell parameter ratio, c/a, of the lamellar microstructure.     

Microstructure and deformation mechanisms in nanocrystalline Ni–Fe. Part I. Microstructure

We investigate various microstructural features of nanocrystalline electrodeposited Ni–Fe with a nominal iron content of 50% and compare them with the well-known nanocrystalline Ni system. In-depth electron microscopy analysis reveals the existence of large strain variations in the grain interior. Three-dimensional atom probe studies demonstrate no significant segregation to grain boundaries. However, significant deviations from a perfect chemically disordered system are found, which can be related to compositional variations of 5% over length scales of only a few nanometres. Finally, X-ray diffraction measurements suggest higher dislocation and twin density in Ni–Fe compared to Ni.     

Slip in directionally solidified Mo-alloy micropillars – Part I: Nominally dislocation-free pillars

In situ Laue analysis during microcompression reveals plasticity in [0 0 1]-oriented, directionally solidified Mo alloy pillars to start with slip on the {1 1 2}〈1 1 1〉 system having the highest Schmid factor followed by slip on the (1 1 0) plane containing the same Burgers vector. The results are interpreted in terms of the microstructure analyzed by scanning transmission electron microscopy and 3-D atom probe.     

Carbon Fiber Reinforced Smart Laminates with Embedded SMA Actuators—Part I: Embedding Techniques and Interface Analysis

Up to now one of the main limits for a large use of shape memory alloys (SMA)-based smart composite structures in the aerospace industry is the lack of useful numerical tools for design. Moreover, technological aspects still need a more detailed investigation. This paper shows how to overcome issues regarding embedding of NiTiNOL wires in carbon fibre/epoxy laminates. A crucial aspect of those structures is related to the load transfer capabilities between the SMA actuators and the host material during their activation. Embedding techniques developed for taking into account problems like thermal and electrical compatibility between actuators and host material and passive/active invasivity are reported in this paper. Simple smart laminates with several actuators were manufactured, tested, and deeply analyzed. In order to characterize the interface in the real operative conditions, pull-out tests were conducted on NiTiNOL wires embedded in composite fiber laminates. The results were compared to standard experiments on wires embedded in pure epoxy resin blocks.     

Preconditioning of AISI 304 stainless steel surfaces in the presence of flavins—Part I: Effect on surface chemistry and corrosion behavior

Stainless steel AISI 304 surfaces were studied after a mild anodic polarization for oxide growth in the presence and absence of two derivatives of vitamin B2 (riboflavin and flavin mononucleotide) that can be secreted by metal-reducing bacteria and act as a chelating agent for iron species. The alterations in oxide chemistry were studied by means of surface-sensitive techniques such as X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry analysis. The complementary electrochemical characterization revealed a preferential growth of an oxide/hydroxide iron-rich film that is responsible for an altered pit initiation and nucleation behavior. These findings suggest that as the corrosion behavior is determined by the interplay of the chemical and electronic properties, only a mild anodic polarization in the presence of redox-active molecules is able to alter the chemical and electronic structure of the passive film formed on stainless steel AISI 304. This helps to achieve a profound understanding of the mechanisms of microbially influenced corrosion (MIC) and especially the possible effects of the redox-active biomolecules, as they may play an important role in the corrosion susceptibility of stainless steel surfaces.     

Quasi-static Tensile and Compressive Behavior of Nanocrystalline Tantalum based on Miniature Specimen Testing—Part I: Materials Processing and Microstructure

Grain size reduction of metals into ultrafine-grained (UFG, grain size 100 nm < d < 1000 nm) and nanocrystalline (NC, d < 100 nm) regimes results in considerable increase in strength along with other changes in mechanical behavior such as vanishing strain hardening and limited ductility. Severe plastic deformation (SPD) has been among the favored technologies for the fabrication of UFG/NC metals. Primary past research efforts on SPD UFG/NC metals have been focused on easy-to-work metals, especially face-centered cubic metals such as copper, nickel, etc., and the limited efforts on body-centered cubic metals have mainly focused on high strain rate behavior where these metals are shown to deform via adiabatic shear bands. Except for the work on Fe, only a few papers can be found associated with UFG/NC refractory metals. In the first part of the present work (Part I), high-pressure torsion (HPT) is used to process UFG/NC tantalum, a typical refractory metal. The microstructure of the HPT disk as a function of radial location as well as orientation will be examined. In the subsequent part (Part II), the location-specific mechanical behavior will be presented and discussed. It is suggested that refractory metals such as Ta are ideal to employ SPD technology for microstructure refinement because of the extremely high melting point and relatively good workability.     

Recovery of scandium from bauxite residue——red mud:a review

Red mud is a slimy caustic residue generated from alumina production. Taking into account the relatively considerable content and availability of scandium, red mud can be viewed as an important and promising scandium resource rather than a solid waste. This paper is primarily to review the investigations of scandium recovery from red mud based on the most widely used hydrometallurgical processes including acid leaching, solvent extraction and ion exchange adsorption. It is thought that recovery of scandium from red mud should be considered as a direct objective rather than a by-product in the development of overall flowsheet. In order to achieve environmentally-friendly processes with high scandium recovery and low cost, more attention is required to be paid to optimizing the selective leaching of scandium to decrease mineral acid consumption and alleviate pollution, and developing new solvent extraction systems and novel ion exchange adsorption materials with high selectivity and recognition for scandium.     

Tool wear estimation in micro-machining.: Part I: tool usage–cutting force relationship

The relationship between the cutting force characteristics and tool usage (wear) in a micro-end-milling operation was studied for two different metals. Neural-network-based usage estimation methods are proposed that use force-variation- and segmental-averaging-based encoding techniques.     

A review on tailored blanks—Production,applications and evaluation

Tailored Blanks is the collective for semi-finished sheet products which are characterised by a local variation of the sheet thickness, sheet material, coating or material properties. With these adaptions the tailored blanks are optimised for a subsequent forming process or the final application. In principle four different approaches can be distinguished to realise tailored blanks: joining materials with different grade, thickness or coating by a welding process (tailor welded blanks), locally reinforcing the blank by adding a second blank (Patchwork blanks), creating a continuous variation of the sheet thickness via a rolling process (tailor rolled blanks) and adapting the material properties by a local heat treatment (tailor heat treated blanks). The major advantage of products made from tailored blanks in comparison to conventional products is a weight reduction. This paper covers the state of the art in scientific research concerning tailored blanks. The review presents the potentials of the technology and chances for further scientific investigations.     

Fabrication,magnetostriction properties and applications of Tb-Dy-Fe alloys：a review

As an excelent giant-magnetostrictive material, Tb-Dy-Fe aloys (based on Tb0.27-0.30Dy0.73-0.70Fe1.9-2 Laves compound) can be applied in many engineering ifelds, such as sonar transducer systems, sensors, and micro-actuators. However, the cost of the rare earth elements Tb and Dy is too high to be widely applied for the materials. Nowadays, there are two different ways to substitute for these aloying elements. One is to partialy replace Tb or Dy by cheaper rare earth elements, such as Pr, Nd, Sm and Ho; and the other is to use non-rare earth elements, such as Co, Al, Mn, Si, Ce, B, Be and C, to substitute Fe to form single MgCu2-type Laves phase and a certain amount of Re-rich phase, which can reduce the brittleness and improve the corrosion resistance of the aloy. This paper systemicaly introduces the development, the fabrication methods and the corresponding preferred growth directions of Tb-Dy-Fe aloys. In addition, the effects of aloying elements and heat treatment on magnetostrictive and mechanical properties of Tb-Dy-Fe aloys are also reviewed, respectively. Finaly, some possible applications of Tb-Dy-Fe aloys are presented.     

Machining of hardened steel—Experimental investigations,performance modeling and cooling techniques: A review

The researchers have worked on many facets of machining of hardened steel using different tool materials and came up with their own recommendations. Researchers have tried to investigate the effects of cutting parameters, tool materials, different coatings and tool geometry on different machinability aspects like, the tool life, surface roughness, cutting forces, chip morphology, residual stresses and the tool–chip interface temperature under dry and/or semi-dry and/or flood cooling environment during machining of hardened steels while many of them have ventured to characterize the wear phenomenon. Good amount of research has been performed on an analytical and/or numerical and/or empirical modeling of the cutting forces, tool–chip interface temperature, and tool wear under orthogonal/oblique cutting conditions during machining of hardened steels. This paper presents a comprehensive literature review on machining of hardened steels using coated tools, studies related to hard turning, different cooling methods and attempts made so far to model machining performance(s) so as to give proper attention to the various researcher works.