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Solder pastes are complex products which are designed to meet the conflicting requirements of printability, slump resistance, good tack and a range of reflow conditions. This paper describes how the metal content and solder particle size distributions in solder pastes affect these properties for a typical RMA type product. The major effects are explained by reference to the purely physical effects of alloy density, metal content and solder powder size on the mean particle separation within the paste. Lower alloy density, high metal content and smaller solder powder size all reduce inter‐particle separations causing viscosity to increase, slump resistance to improve and peak tack force to increase. The paper also discusses the more subtle effects of the chemical interactions between solder powder and flux medium on the same properties. These are illustrated by reference to the changes which take place in performance of a typical solder paste during storage over 12 months. Ageing by solvent loss and rosin drying brought about by the effects of metal soaps formed between solder and activators probably contribute to these changes. Ageing can result in improved performance in tests like slump resistance and consequently solder balling, while in others, such as open time, there is a decrease in performance.

Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

This study aims on a broad review of Concrete's Rheological Properties. The Concrete is a commonly used engineering material because of its exquisite mechanical interpretation, but the addition of constituent amounts has significant effects on the concrete’s fresh properties. The workability of the concrete mixture is a short-term property, but it is anticipated to affect the concrete’s long-term property.

In this review, the concrete and workability definition; concrete’s rheology models like Bingham model, thixotropy model, H-B model and modified Bingham model; obtained rheological parameters of concrete; the effect of constituent’s rheological properties, which includes cement and aggregates; and the concrete’s rheological properties such as consistency, mobility, compatibility, workability and stability were studied in detail.

Also, this review study has detailed the constituents and concrete’s rheological properties effects. Moreover, it exhibits the relationship between yield stress and plastic viscosity in concrete’s rheological behavior. Hence, several methods have been reviewed, and performance has been noted. In that, the abrasion resistance concrete has attained the maximum compressive strength of 73.6 Mpa; the thixotropy approach has gained the lowest plastic viscosity at 22 Pa.s; and the model coaxial cylinder has recorded the lowest stress rate at 8 Pa.

This paper especially describes the possible strategies to constrain improper prediction of concrete’s rheological properties that make the workability and rheological behavior prediction simpler and more accurate. From this, future guidelines can afford for prediction of concrete rheological behavior by implementing novel enhancing numerical techniques and exploring the finest process to evaluate the workability.

The purpose of this paper is to present experimental research on the behaviour of a new electrorheological fluid (ETSERF).

The ETSERF is a suspension based on diatomite powders dispersed in silicon oil with a surfactant. A design of experiments is conducted to investigate the effects of electric field strength, particle concentration, surfactant percentage, particle size and shear rate on the efficiency of ETSERFs. The influence of the interactions on shear stresses is analyzed by varying all the combinations of the independent variables. The dielectric properties of the ETSERF are investigated in order to explain the interactions between these independent variables. Furthermore, a quantitative relationship between the dynamic shear stresses and the independent variables is developed.

The relationship provides a very useful explanation for the contributions of each independent variable to the viscosity and yield stress.

A new empirical model is proposed to explain the rheological behaviour of the ER fluids with a shear‐thinning behaviour.

‘Fine Pitch’ and ‘High speed printing’ are relative terms but many solder paste users see capability in meeting these two requirements as their major goals for process improvements. Not surprisingly, solder paste rheology governs both, and this paper describes how the complex relationship between resins and solvent can lead to solder pastes with optimised performance. Work on the physical behaviour of resin solutions and how this relates to solder paste rheology is reported. These results are related to user experience on volume production processes.

The purpose of this study is therefore to detail an additive manufacturing process for printing TiD parts for implant applications. Titanium–diamond (TiD) is a new composite that provides biocompatible three-dimensional multimaterial structures. Thus, the authors report a powder-deposition and print optimization strategy to overcome the dual-functionality gap by printing bulk TiD parts. However, despite favorable customization outcomes, relatively few additive manufacturing (AM) feedstock powders offer the biocompatibility required for medical implant and device technologies.

AM offers a platform to fabricate customized patient-specific parts. Developing feedstock that can be 3D printed into specific 3D structures while providing a favorable interface with the human tissue remains a challenge. Using laser metal deposition, feedstock powder comprising diamond and titanium was co-printed into TiD parts for mechanical testing to determine optimal manufacturing parameters.

TiD parts were fabricated comprising 30% and 50% diamond. The composite powder had a Hausner ratio of 1.13 and 1.21 for 30% and 50% TiD, respectively. The flow analysis (Carney flow) for TiD 30% and 50% was 7.53 and 5.15 g/s. The authors report that the printing-specific conditions significantly affect the integrity of the printed part and thus provide the optimal manufacturing parameters for structural integrity as determined by micro-computed tomography, nanoindentation and biocompatibility of TiD parts. The hardness, ultimate tensile strength and yield strength for TiD are 4–6 GPa (depending on build position), 426 MPa and 375 MPa, respectively. Furthermore, the authors show that increasing diamond composition to 30% results in higher osteoblast viability and lower bacteria count than titanium.

In this study, the authors provide a clear strategy to manufacture TiD parts with high integrity, performance and biocompatibility, expanding the material feedstock library and paving the way to customized diamond implants. Diamond is showing strong potential as a biomedical material; however, upscale is limited by conventional techniques. By optimizing AM as the avenue to make complex shapes, the authors open up the possibility of patient-specific diamond implant solutions.

The purpose of this paper is to investigate how the formulation of a solder paste (with regards to the flux and particle size distribution (PSD)), can influence its creep and recovery performance.

New lead‐free paste formulations were characterised utilising viscometry and oscillatory methods, after which creep/recovery investigations were conducted to determine the recovery performance. Measurements were recorded using a rheometer with a parallel plate geometry of 40 mm and a sample height of 1 mm.

Results from the study highlighted that the formulation of a solder paste can have a significant impact on the creep/recovery measurements. Variations in flux and PSD highlighted a considerable difference in the recoverability of the solder pastes, in one instance demonstrating more than a 20 per cent increase in structural recovery.

More extensive research is needed relating to reduced PSDs, such as type 6 and 7 solder pastes, to fully understand their influence on the creep/recovery performance.

The results presented in this paper emphasise important information and investigational methods for research and development, and quality control.

The paper highlights how the composition of new paste formulations can influence the creep/recovery behaviour. It was found that the recoverability can be increased by careful selection of the flux and PSD, which in turn could reduce slumping influences in the print process. If used as a quality control tool, this paper may allow for the reduction in print defect occurrence.