Overview of Lightweight Ferrous Materials: Strategies and Promises

Reducing the density of steels is a novel approach for weight reduction of automobiles to improve fuel efficiency. In this overview article, strategies for the development of lightweight steels are presented with a focus on bulk ferrous alloys. The metallurgical principles of these steels and their mechanical properties of relevance to automotive applications are discussed. Some of the engineering aspects highlighting the possible problems related to mass production of these steels are also considered. Application prospects of these steels vis-à-vis standard automotive steels are shown.     

Automotive carbon fiber: Opportunities and challenges

The carbon fiber industry is growing, with steadily increasing demand from the aerospace and defense markets as well as smaller markets such as sporting goods and construction materials. Infiltration of the automotive market remains a challenge, however, and so the U.S. Department of Energy's (DOE) FreedomCAR program has made the development of low-cost automotivegrade carbon fiber its highest priority for materials research. The DOE effort is currently focused on three objectives: developing low-cost carbon fiber precursors, low-cost conversion methods, and high-throughput fabrication processes.     

Modeling mechanical alloying: Advances and challenges

While mechanical alloying is a commercial entity for oxide-dispersion-strengthened superalloys, its application to other systems has run into a number of scientific and commercial barriers. In part, this is due to the inadequate scientific underpinning. This article reviews the status of the modeling of the mechanical alloying processes and suggests an approach to improving current knowledge of the process.     

Sodium-beta alumina batteries: Status and challenges

This paper provides a review of materials and designs for sodium-beta alumina battery technology and discusses the challenges ahead for further technology improvement. Sodium-beta alumina batteries have been extensively developed in recent years and encouraging progress in performance and cycle life has been achieved. The battery is composed of an anode, typically molten sodium, and a cathode that can be molten sulfur (Na-S battery) or a transition metal halide incorporated with a liquid phase secondary electrolyte (e.g., ZEBRA battery). In most cases the electrolyte is a dense solid β″-Al₂O₃ sodium ion-conducting membrane. The issues prohibiting widespread commercialization of sodium-beta alumina technology are related to the materials and methods of manufacturing that impact cost, safety, and performance characteristics.     

High-temperature nanoindentation: New developments and ongoing challenges

High-temperature or elevated-temperature nanoindentation testing presents an additional capability in nanoindentation techniques, which have demonstrated tremendous potential in the study of nanoscale mechanical behavior. However, to be able to conduct nanoindentation under relevant service temperatures and to gain a better understanding of the fundamental materials physics, high-temperature nanoindentation must overcome such technical issues as heat management, thermal drift, and sample oxidation. This article presents the current state and history of high-temperature nanoindentation with a focus on recent research topics and available testing systems.     

Teleservice engineering in manufacturing: challenges and opportunities

This position paper introduces the concept and framework of a teleservice engineering system for the life cycle support of manufacturing equipment and products. The proposed system involves the fundamental methodologies that deal with machine performance assessment techniques, self-maintenance machine mechatronics, and remote diagnostics. In addition, a concept on digital service enterprise will be introduced. These methodologies will support remote users and facilities to ensure the performance of consumer products, manufacturing equipment, quality of operations, and productivity of the plant, in particular, for those users and facilities located in remote locations. Finally, research challenges and opportunities are discussed.     

Aluminum: New challenges in downstream activities

During its history, aluminum’s attractive features, such as high strength-to-weight ratio, good electrical mass conductivity, and unique corrosion behavior, have led to a spectacular expansion in its use. The role of aluminum in non-aluminum-based materials is also very important; its contribution to the improvement of magnesium and titanium alloys and to highly complex packaging materials are some of the noteworthy examples. Significant cost reductions on the basic metal production level, near-to-shape fabricating methods, and the well-functioning recycling system are also major contributors to aluminum success. Imminent challenges for the industry are the need for products with very close tolerances on a mass fabricating repetitive basis and just-in-time delivery to original-equipment manufacturers and small users through distributors. A significant part of the challenges remains in the applications area, particularly automotive and aerospace.     

Metal-matrix composites in the automotive industry: Opportunities and challenges

Metal-matrix composites offer considerable promise to help automotive engineers meet the challenges of current and future demands for recyclable, fuel-efficient, safe, and low-emission vehicles. These materials can be engineered to match the design requirements of automotive power-train or chassis components. Technological and infrastructural barriers tend to limit the implementation of these materials, but it is believed these barriers can be overcome and that metal-matrix composites can be applied in high-volume vehicle production. Reducing these barriers will require much effort by engineers and scientists, managers and planners at automotive manufacturers, and their suppliers. The result will be the gradual introduction of metal-matrix composites in high-volume vehicle production to satisfy customer desires while meeting regulatory requirements and competitive pressures.     

Ferritic steels for sodium-cooled fast reactors: Design principles and challenges

An overview of the current status of development of ferritic steels for emerging fast reactor technologies is presented in this paper. The creep-resistant 9–12Cr ferritic/martensitic steels are classically known for steam generator applications. The excellent void swelling resistance of ferritic steels enabled the identification of their potential for core component applications of fast reactors. Since then, an extensive knowledge base has been generated by identifying the empirical correlations between chemistry of the steels, heat treatment, structure, and properties, in addition to their in-reactor behavior. A few concerns have also been identified which pertain to high-temperature irradiation creep, embrittlement, Type IV cracking in creep-loaded weldments, and hard zone formation in dissimilar joints. The origin of these problems and the methodologies to overcome the limitations are highlighted. Finally, the suitability of the ferritic steels is re-evaluated in the emerging scenario of the fast reactor technology, with a target of achieving better breeding ratio and improved thermal efficiency.     

The use of titanium in production automobiles: Potential and challenges

Titanium offers a number of attractive features for use in high-production-volume automobiles; however, high cost has been a barrier to application, thus far. This article discusses the potential and challenges for the use of titanium in the family automobile. A.M. Sherman earned his Ph.D. in metallurgy at the Massachusetts Institute of Technology in 1972. He is currently senior staff technical specialist at Ford Motor Company. Dr. Sherman is a member of TMS. C.J. Sommer earned his B.S. in metallurgical engineering at University of Pittsburgh in 1982. He is currently manager of automotive marketing at Timet. F.H. Froes earned his Ph.D. in physical metallurgy at Sheffield University in 1967. He is currently the director of the Institute for Materials and Advanced Processes at the University of Idaho. Dr. Froes is also a member of TMS.     

Shear viscosity of inorganic glasses and polymers

The viscosity of metaphosphate glasses and polystyrene was measured in the shear deformation mode above and below the glass transition temperature T_g. The temperature dependence of the viscosity above T_g was well expressed by the Vogel–Tammann–Fulcher formula, while two relaxations of thermal activation type appeared below T_g. The overall temperature dependence in both materials was very similar with each other. The relaxation at the lower temperature was found to be sensitive to the internal state of the materials.     

Metal-based inorganic nanocrystals for biological sonodynamic therapy applications:recent progress and perspectives

With the fast development of technology for the treatment of tumor and bacteria,photo-therapeutic strategies emerge as a kind of highly effective and common treatment,but the low tissue penetration depth of light limits their development.Sonodynamic therapy(SDT),as an efficient and non-invasive treatment,attracts more people’s attention due to the inherent property of high tissue penetration.The soft tissue penetration depth of ultrasound(US) can even reach more than 10 cm,which has great advant...