After almost three decades of intensive fundamental research and development activities, intermetallic titanium aluminides based on the ordered γ-TiAl phase have found applications in automotive and aircraft engine industry. The advantages of this class of innovative high-temperature materials are their low density and their good strength and creep properties up to 750 °C as well as their good oxidation and burn resistance. Advanced TiAl alloys are complex multi-phase alloys which can be processed by ingot or powder metallurgy as well as precision casting methods. Each process leads to specific microstructures which can be altered and optimized by thermo-mechanical processing and/or subsequent heat treatments. The background of these heat treatments is at least twofold, i.e., concurrent increase of ductility at room temperature and creep strength at elevated temperature. This review gives a general survey of engineering γ-TiAl based alloys, but concentrates on β-solidifying γ-TiAl based alloys which show excellent hot-workability and balanced mechanical properties when subjected to adapted heat treatments. The content of this paper comprises alloy design strategies, progress in processing, evolution of microstructure, mechanical properties as well as application-oriented aspects, but also shows how sophisticated ex situ and in situ methods can be employed to establish phase diagrams and to investigate the evolution of the micro- and nanostructure during hot-working and subsequent heat treatments.

Design, Processing, Microstructure, Properties, and Applications of Advanced Intermetallic TiAl Alloys†

High entropy alloys: A focused review of mechanical properties and deformation mechanisms

Engineering biocompatible implant surfaces

Comparison of the microstructures and mechanical properties of Ti–6Al–4V fabricated by selective laser melting and electron beam melting

Imbalances between metal supply and demand, real or anticipated, have inspired the concept of metal criticality We here characterize the criticality of 62 metals and metalloids in a 3D “criticality space” consisting of supply risk, environmental implications, and vulnerability to supply restriction Contributing factors that lead to extreme values include high geopolitical concentration of primary production, lack of available suitable substitutes, and political instability The results show that the limitations for many metals important in emerging electronics (eg, gallium and selenium) are largely those related to supply risk; those of platinum group metals, gold, and mercury, to environmental implications; and steel alloying elements (eg, chromium and niobium) as well as elements used in high-temperature alloys (eg, tungsten and molybdenum), to vulnerability to supply restriction The metals of most concern tend to be those available largely or entirely as byproducts, used in small quantities for highly specialized applications, and possessing no effective substitutes

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Criticality of metals and metalloids.

The chapter discusses various methods used to treat titanium and titanium alloys for adhesive bonding. It is reported that both alkaline cleaning and phosphate-fluoride prebond treatments produce surfaces of good wettability, equal thickness and similar composition. Stabilized phosphate-fluoride process retards the conversion of anatase to rutile. It is also reported that the anodic process produces a porous oxide structure and is superior to the surface formed by the phosphate-fluoride process. Specific treatments for aluminum and aluminum alloys are presented in a process specification format including anodize process, Turco 5578, liquid hone/Pasa-Jell 107 process, dry hone/Pasa-Jell 107 process, alkaline peroxide process and stabilized phosphate-fluoride process. A study of the morphology and decomposition of the various surfaces revealed that different surface morphologies are obtained with the different treatments. The treatments were classified into three different groups. The Group I processes were characterized as producing surfaces which have thin oxide layers with little macro-roughness while Group II processes resulted in surfaces which had a high degree of macro-roughness. The Group III processes produced surfaces which were characterized by a primarily micro-rough porous oxide.

Titanium and Titanium Alloys

The chapter discusses various methods used to treat copper and copper alloys for adhesive bonding. The tendency of copper to form brittle amine compounds with the amine curing agents is one of the difficulties in its adhesive bonding. There are numerous reported surface preparations for copper and copper alloys including ferric chloride-nitric acid process, ferric sulfate-sulfuric acid/sodium dichromate-sulfuric acid process and black oxide process. A barrier layer on the surface of the metal can be formed by using the black oxide process. It provides a description on the evaluation of ferric chloride-nitric acid process and the ferric sulfate-sulfuric acid/sodium dichromate-sulfuric acid process with three epoxy type adhesive systems. The epoxy type adhesive system includes a two part polyamide-epoxy consisting of epoxy paste and curing epoxy film adhesive. It is also observed that with the use of ferric chloride-nitric acid process the resulting surfaces appear to be light-sensitive.

Copper and Copper Alloys

"Surface Preparation Techniques for Adhesive Bonding" is an essential guide for materials scientists, mechanical engineers, plastics engineers, scientists and researchers in manufacturing environments making use of adhesives technology. Wegman and van Twisk provide practical coverage of a topic that receives only cursory treatment in more general books on adhesives, making this book essential reading for adhesion specialists, plastics engineers, and a wide range of engineers and scientists working in sectors where adhesion is an important technology, e.g. automotive / aerospace, medical devices, electronics. Wegman and van Twisk provide a wealth of practical information on the processing of substrate surfaces prior to adhesive bonding. The processing of aluminum and its alloys, titanium and its alloys, steels, copper and its alloys, and magnesium are treated in the form of detailed specifications with comparative data. Other metals not requiring extensive treatment are also covered in detail, as are metal matrix and organic matrix composites, thermosets and thermoplastics. This new edition has been updated with coverage of the latest developments in the field including the sol-gel process for aluminum, titanium, and stainless steel, atmospheric plasma treatment for metals, plastics and rubbers and treatments for bronze and nickel alloys. Updated to include recent technological developments and chemicals currently prescribed for cleaning and surface preparation; a new generation of adhesives technologists can benefit from this classic guide. It enables Materials and Process personnel to select the best process available for their particular application. It is a practical coverage of a topic that receives only cursory coverage in more general books on adhesives: essential reading for adhesion specialists, plastics engineers, and a wide range of engineers and scientists working in sectors where adhesion is an important technology, e.g. automotive / aerospace, medical devices, electronics.

Surface Preparation Techniques for Adhesive Bonding

Lifestyle factors have been associated with the development and progression of rheumatoid arthritis (RA). Interventions involving whole food plant-based diets (WFPDs), physical activity or stress management have shown promising results for people with RA but were not yet evaluated in an integrated program.To determine the effect of a 16-week multidisciplinary lifestyle program on disease activity in patients with RA.In the “Plants for Joints” (PFJ) parallel-arm, assessor-blind randomized clinical trial, patients with RA and a 28-joint Disease Activity Score [DAS28] score ≥ 2.6 and ≤ 5.1, were assigned to the PFJ group or the control group. The PFJ group followed a lifestyle program based on a WFPD, physical activity, and stress management in addition to usual care. The control group received usual care. Medication was kept stable three months before and during the trial. Secondary outcomes included anthropometric, and metabolic markers. An intention-to-treat analysis with a linear mixed model, adjusted for baseline values was used to analyze between-group differences of continuous outcomes.Of 115 people screened, 85 were randomized and 79 completed the study. Participants were 91% female with a mean (SD) age of 55 (12) and body mass index of 26 (4) kg/m2. After 16 weeks the PFJ group had a mean 0.85-point greater improvement of the DAS28 versus the control group (95% CI 0.40 to 1.30; p < 0.001) (Figure 1). Subgroup analyses showed significant improvements in the seropositive as well as the seronegative subgroup, although the effect was more profound in the seronegative group. Weight, fat mass, HbA1c, LDL and triglycerides also showed significant improvements in the PFJ versus control group, while blood glucose and HDL remained unchanged (Table 1). No serious adverse events occurred.The 16-week PFJ lifestyle program substantially decreased disease activity in people with RA with low-moderate disease activity.Wendy Walrabenstein: None declared, Carlijn Wagenaar: None declared, Marike van der Leeden: None declared, Franktien Turkstra: None declared, Jos Twisk: None declared, Maarten Boers Consultant of: Consultant for Novartis, Henriët van Middendorp: None declared, Peter Weijs: None declared, Dirkjan van Schaardenburg: None declared

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Ab0396 effect of a multidisciplinary lifestyle program in patients with rheumatoid arthritis: the plants for joints randomized controlled trial

The chapter discusses various methods used to treat steel for adhesive bonding focusing mainly on carbon steels, low alloy steels and stainless steels It states that the key factors to be considered when bonding to steel are cleanliness and descaling or rust, oxide removal, and passivation (in case of stainless steel) Corrosion resistance of stainless steel is accomplished by passivation which is defined as making a surface inactive, or less reactive It also outlines the disadvantages of chemical etchants over mechanical surface preparations There are numerous reported surface preparations for carbon, low alloy and stainless steels including phosphoric acid-alcohol process, nitric-phosphoric acid process, sulfuric acid-sodium dichromate process and sulfuric acid-sodium bisulfate process It provides an overview of steps involved in the preparation for bonding to oily steel Information related to the corrosion resistant conversion coatings of steel is presented Surface treatments for stainless steel and specialty stainless steel are described in detail including discussion on AM 355 stainless steel

James Van Twisk

Papers

Titanium and Titanium Alloys

Copper and Copper Alloys

Surface Preparation Techniques for Adhesive Bonding

Ab0396 effect of a multidisciplinary lifestyle program in patients with rheumatoid arthritis: the plants for joints randomized controlled trial

Steel and Stainless Steel