Steels represent the most widely-used metallic alloy, possessing a wide range of microstructures and mechanical properties. By examining the mechanical properties of steels in conjunction with ...microstructure this book provides a valuable description of the development and behavior of these materials, the very foundation of their widespread use. Updated throughout and including new chapters on nanostructured steels, and new alloys and technologies for the energy and automobile industries, the book is clearly written and illustrated, with extensive bibliographies and real-life examples. This is an essential reference, both compact and readily comprehensive, for metallurgists and engineers, as well as senior undergraduate students and postgraduates in materials science, physical metallurgy and mechanical engineering.
The low creep resistance has been one of the major issues of Mg alloys, which limited their wider industrial applications in the past decades. It has been reported that the inherent creep resistance ...of Mg should be higher than that Al. Hence, it is highly likely that the low creep resistance of Mg alloys was attributed to the effects of alloying elements rather than Mg itself. In order to systematically understand the effects of alloying elements on the creep behaviours of cast Mg alloys and therefore to develop new alloys with higher creep resistance, the present work reviews the major creep-resistant Mg systems that were developed and successfully commercialized for applications at different temperatures. Because the majority of commercial Mg alloys are used as cast, this review focuses on cast alloys.
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•The creep behaviour of major creep-resistant Mg systems is reviewed.•The effect of various alloying elements on creep behaviours is discussed.•The strengthening mechanisms to creep resistance of Mg alloys are discussed.
Mg-Zn binary alloys with seven distinctive compositions (Zn (wt.%) = 1, 2, 4, 6, 8, 10 and 12) were prepared using a selective laser melting (SLM) additive manufacturing technology. Densification ...behaviors and microstructure of the SLM-processed alloys were analyzed using quantitative metallography analysis, XRD, SEM, and EDS. The mechanical property characterizations were carried out through microhardness and uniaxial tensile tests. The results showed that the increase of Zn content had a significantly deteriorating effect on the densification response of the SLM-processed Mg-Zn alloys. At 1 wt% Zn content, near full-dense products could be obtained. At 2–10 wt% Zn contents, SLM-processed alloys suffered from solidification cracking and the crack density showed an approximate “Λ-shaped” variation trend with the increase of Zn content. At 12 wt% Zn content, solidification cracks were eliminated but lots of micro-pores formed within the SLM sample. All the SLM samples exhibited a duplex microstructure composed of α-Mg matrix and Mg7Zn3 eutectic phase. With the increase of Zn content, the quantity of Mg7Zn3 increased continuously whilst its morphology gradually transformed from granular shape to nearly reticular structure. The hardness and tensile tests showed that only the Mg-1Zn sample has comparable mechanical properties with the as-cast counterpart. At higher Zn contents, mechanical properties of the SLM-processed alloys became significantly degraded, mainly because of the deterioration of the densification degree.
Progress in metallo-supramolecular chemistry creates potential to synthesize functional nano systems and intelligent materials of increasing complexity. In the past four decades, metal-mediated ...self-assembly has produced a wide range of structural motifs such as helicates, grids, links, knots, spheres and cages, with particularly the latter ones catching growing attention, owing to their nano-scale cavities. Assemblies serving as hosts allow application as selective receptors, confined reaction environments and more. Recently, the field has made big steps forward by implementing dedicated functionality,
e.g.
catalytic centres or photoswitches to allow stimuli control. Besides incorporation in homoleptic systems, composed of one type of ligand, desire arose to include more than one function within the same assembly. Inspiration comes from natural enzymes that congregate, for example, a substrate recognition site, an allosteric regulator element and a reaction centre. Combining several functionalities without creating statistical mixtures, however, requires a toolbox of sophisticated assembly strategies. This review showcases the implementation of function into self-assembled cages and devises strategies to selectively form heteroleptic structures. We discuss first examples resulting from a combination of both principles, namely multicomponent multifunctional host-guest complexes, and their potential in application in areas such as sensing, catalysis, and photo-redox systems.
This review highlights recent strategies towards the rational synthesis of metallo-supramolecular multicomponent systems, the implementation of functionality and the challenge to create multifunctional assemblies in non-statistical fashion.
Metals play vital roles in nutrients and medicines and provide chemical functionalities that are not accessible to purely organic compounds. At least 10 metals are essential for human life and about ...46 other non-essential metals (including radionuclides) are also used in drug therapies and diagnostic agents. These include platinum drugs (in 50% of cancer chemotherapies), lithium (bipolar disorders), silver (antimicrobials), and bismuth (broad-spectrum antibiotics). While the quest for novel and better drugs is now as urgent as ever, drug discovery and development pipelines established for organic drugs and based on target identification and high-throughput screening of compound libraries are less effective when applied to metallodrugs. Metallodrugs are often prodrugs which undergo activation by ligand substitution or redox reactions, and are multi-targeting, all of which need to be considered when establishing structure-activity relationships. We focus on early-stage
in vitro
drug discovery, highlighting the challenges of evaluating anticancer, antimicrobial and antiviral metallo-pharmacophores in cultured cells, and identifying their targets. We highlight advances in the application of metal-specific techniques that can assist the preclinical development, including synchrotron X-ray spectro(micro)scopy, luminescence, and mass spectrometry-based methods, combined with proteomic and genomic (metallomic) approaches. A deeper understanding of the behavior of metals and metallodrugs in biological systems is not only key to the design of novel agents with unique mechanisms of action, but also to new understanding of clinically-established drugs.
The vital roles of metals in nutrients and medicines are not accessible to purely organic compounds.
A new click chemistry generated artificial metallonuclease is reported in the Research Article by Andrew Kellett et al. (e202305759). The oxidative DNA damaging properties of a polynuclear copper ...binding ligand called TC‐Thio is demonstrated. Copper‐TC‐Thio binds in the minor groove of genomic DNA and promotes damage via a superoxide linked mechanism. The inset picture shows copper ions, bound to the TC‐Thio ligand, melting into the DNA duplex and filling the reaction chamber with molten liquid DNA.
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