This study investigates the cavitation erosion performance of heavy-duty engine coolants before and after operation in trucks using an ultrasonic test rig based on ASTM G32. Fresh coolants with 35% and 50% v/v glycol were compared with used coolants. One coolant was obtained from a gasoline-fueled vehicle with a mileage of 27 000 km, and two from diesel-fueled vehicles with mileages of 16 000 and 180 000 km, respectively. Surface tension and boiling point at atmospheric pressure were measured, a chemical analysis was carried out, and suspended particles were quantified by dynamic image analysis. The results showed that the used coolants caused a lower mass loss in ultrasonic cavitation testing than the fresh ones, and that they had higher boiling points, lower pH and a higher number of suspended particles, especially of those smaller than 30μm. Surface tension was higher for the used coolants from Diesel engines. The lower mass loss caused by all three used coolants can be attributed mainly to their high boiling point and high particle count. The presence of particles is believed to promote the heterogeneous nucleation of smaller, more stable bubbles, which may protect the exposed surface by shockwave absorption and microjet deflection. Some dissolved ions in the used coolants may help reduce their aggressivity by inhibiting bubble coalescence, reducing bubble collapse energy, despite increasing surface tension. Surface tension has complex interactions with the solutes, particles and bubble formation and cannot, in isolation, explain the differences in performance of the coolants.

Bifilms have been proposed to be critical for forming casting defects. The reduced pressure test (RPT) and bifilm index (BI) have been widely studied and used in industry for melt quality assessment. However, the BI remains challenged in predicting the mechanical properties. This work investigated the usage of RPT for elongation prediction by analyzing the melt in two foundries. The results showed that the BI could be valid when the bifilms exist as fully inflated pores. In reality, bifilms present as pores with various morphology and distribution, generating local stress concentrations under tension. Consequently, the parameter areaeff, which considers the pores’ morphology and distribution, was proposed, and the resultant f eff showed a good correlation with the elongation of the castings. These results guide the foundry to predict the elongation of the final castings and give directions for further research on the bifilm defects.

In order to visualise the phase diagram of a quaternary system under constant temperature and pressure one would need three dimensions. However, in some cases much information can be presented in a quasi-ternary section. This is the case for the Si-Al-O-N system where all the condensed phases fall in or very close to the section defined by the corners Si3N4, SiO2, Al2O3 and AIN as if all the phases were ionic and composed of Si+4, Al+3, O-2 and N-3, which is not quite true. It has been possible to model the properties of the condensed phases using models which restrict their existence to the section mentioned. The modelling will now be described briefly and it will be demonstrated that it was possible to extrapolate the properties of the ternary side systems and use the meagre information available from the quaternary system in order to predict the phase relations [91Hill2].

The influence of Na-Based flux on the melt quality assessment was studied using Density index (DI), bifilm index (BI) and tensile test. The melt was prepared with scrap and ingot with and/or without the addition of Na-based flux. The results show that the addition of Na-based flux decreases the accuracy of the correlation between BI/DI and the hydrogen content due to the increased shrinkage pores. The addition of flux promotes the formation of shrinkage pores by either altering the eutectic solidification behavior or generating more and bigger oxide films which leads to insufficient feeding. Moreover, the addition of flux improves the ductility of specimens by modifying the eutectic phase rather than improving the melt quality.

The surface liquid segregation (SLS) layer in semisolid casting presents higher hardness than the surface of specimens cast using high-pressure die casting (HPDC). Bending fatigue tests showed that semisolid castings present better fatigue properties at higher stress, and this improvement disappears when the applied stress is lower than a critical load. This is because HPDC and SSM castings share the same surface deformation at low stress. More significant deformation is observed for HPDC castings when the stress exceeds the critical load. The presence of surface defects enlarges the difference in deformation at high stress and reduces the critical load.

Metal casting is an industrially important manufacturing process offering a superior combination of design flexibility, productivity and cost-effectiveness, but has limitations due to filling related defects. Several semisolid casting processes are available capable of casting at a range of solid fractions to overcome this. The current communication aims to review the filling front behaviour and give a new perspective to the gate design in semisolid processing compared to conventional high-pressure die-casting. It is shown that solid fraction and gate widths are critical to avoid instability and spraying.

Endothelial cells play an important role in several vascular diseases, and molecular analysis of these cells could provide valuable information on underlying tissue status. However, no clinically established procedure for harvesting endothelial cells exists. A micro-3D-printed device adapted for endovascular techniques to harvest endothelial cells for transcriptomic analysis is presented. In vivo evaluation in swine (n = 6) yielded tissue samples in 60 out of 65 cases, of which 80% show a substantial amount of tissue. The cytological evaluation indicates high selectivity towards endothelial cells, and RNA-sequencing shows gene expression signatures consistent with vascular tissue. It is found that there are no short-term safety risks compared to operation with a control wire of equal dimensions and acute complications are not detected. If translated to clinical use, the device could enable increased understanding of early-stage endothelial cell-mediated disease progression and earlier diagnosis of diseases such as atherosclerosis.

Treatment of the slurry is important during RheoMetalTM casting. In this work, semi-solid slurries were prepared under different stirring intensities, using two types of stirrers: a naked rod (for regular stirring) and a rod with two blades (for intensive stirring). Tensile tests were performed, investigating fracture surfaces, as well as metallographic samples. The results show that intensive stirring produces castings with finer primary particles and a more homogeneous microstructure. On the other hand, more faceted Fe-rich phases are found along the α-Al grains boundary, due to the dissolution of Fe from the stirrers. Moreover, for intensive stirring castings, the porosity found on the fracture surfaces are smaller, while more second (intermetallic) phases, especially Fe-rich phases, are observed. Consequently, the castings with intensive stirring show worse ductility. Finally, a quantitative analysis was made regarding ductility, affected both by porosity and the presence of Fe-rich phases. 

The KTH Royal Institute of Technology (Stockholm, Sweden) as a project leader allowed strengthening collaboration between academic and industrial experts in the field of non-destructive testing (NDT), machining and metrology. This scientific consortium had found an efficient way for scientific collaboration, in which we conducted many experiments, meetings, and talks on the project’s research subject. This book is a result of all the mentioned activities and more. Many experts from both sides actively participated in the creation of this guide and are listed in the list of contributors.

The authors hope that after reading this guide, BN measurements can be carried out more systematically, with higher accuracy, traceability and lower uncertainty. The authors do not aim to replace a whole raft of good textbooks, operator’s manuals, specifications, and standards (if they exist); rather, they want to present an overview of good practices and techniques. These recommendations are also a result of many discussions conducted by the project team members during the project’s duration.

The book is divided into two parts. The first part of the book, “Measurement Good Practice Guide”, presents a comprehensive overview of the Barkhausen noise (BN) measurement method used to describe and analyze different features of ferromagnetic materials, such as residual stress level, hardening depth, among others. The primary focus is on mechanical parts for the automotive industry, in particular, the camshaft and crankshaft. The good practice guide is intended for those who need to make BN measurements but are not necessarily trained to use this method or are still not comfortable about measurement itself. By reading this guide, one can gain basic knowledge regarding good practices for making magnetic measurements with the BN method. Based on a few principles and tips from good practices, the reader will be able to create a Standard Operating Procedure (SOP) for their purpose. SOPs for BN are presented in the appendices.

The second part of the book “Qualification and Certification of Personnel” presents requirements of the personal certification for Barkhausen testing and is aligned with applicable standards. The authors recommend performing internal and external certification of personnel to do achieve more conscious and reliable measurements.

This book has been prepared by the scientific consortium under the research project FFI OFP4p – Non-Destructive Characterization Concepts for Production, 2015–2018 co-founded in 50% by VINNOVA, Sweden’s innovation agency. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights.

Endothelial cells lining blood vessels have phenotypic variations that indicate the health/disease status for a variety of conditions, including atherosclerosis and hypertension. Current sampling strategies lead to a high variation in the sampled amount, and we are not aware of sampling tools specifically targeting endothelial cells. Here, we present a new type of endovascular catheter for sampling of the blood vessel wall. The catheter is a 380 mu m nitinol tube over which 3D printed graters are threaded. The catheter is designed to be non-invasive during the axial motion and to interact with the blood vessel wall when rotated. Initial results indicate successful in-vivo sampling - with minimal blood contamination - of the wall of blood vessels less than 0.5 mm in diameter.