Present status of research on design and processing of functionally graded materials

Recent activities in the research of functionally graded materials (FGMs) are reviewed with an emphasis on the fabrication techniques for graded microstructure and functions. The research activities have focused on the processing of graded structures that satisfy the designed functions. Several examples of practical applications of FGMs are described in the present paper to demonstrate the fabrication approaches typical to this kind of material. The remainder of the paper is devoted to summarizing a recently finished national project supported by the Ministry of Education of Japan. Research and developments with respect to FGMs in various fields including physics, chemistry, medical science, and biology are briefly reviewed. This article is based on a presentation made in the symposium “The 3rd KIM-JIM Joint Symposium on Advanced Powder Materials”, held at Korea University, Seoul, Korea, October 26–27, 2001 under auspices of The Korean Institute of Metals and Materials and The Japan Institute of Metals. Present at the Fine Ceramic Center, Atsuta-ku, Nagoya, Japan     

Microstructure and Properties of Hydroxyapatite-Containing Ceramic Coatings on Magnesium Alloys by One-Step Micro-Arc Oxidation

Protection of Metals and Physical Chemistry of Surfaces - Mg and its alloys are considered as biodegradable metallic implant materials, are attracting great attentions. However, the corrosion...     

Corrosion,Mechanical and Catalytic Properties of Coatings Based on FeNiCrWMoCoCB Metallic Glasses

Protection of Metals and Physical Chemistry of Surfaces - This work is devoted to the deposition of coatings based on FeNiCrWMoCoCB metallic glasses on a surface made of 35 steel; the deposition is...     

Investigation on Wear Behavior of Steels Coated with WC by ESD Technique

Protection of Metals and Physical Chemistry of Surfaces - Electro-spark deposition (ESD) or low energy welding (LEW) technique allows the coating of metallic materials with different metal and...     

Insight into the Electrochemical and Semiconducting Properties of Native Oxide Films on Ti Metal and Its Ti–6Al–4V Alloy in Borate Buffer Solutions

Protection of Metals and Physical Chemistry of Surfaces - Titanium and titanium alloys are intriguing materials having widespread industrial and medical applications due to their excellent...     

HAP Coatings for Biomedical Applications: Biocompatibility and Surface Protection Against Corrosion of Ti,Ti6Al4V and AISI 316L SS

Protection of Metals and Physical Chemistry of Surfaces - The implants used as cardio stents, orthopedic and dental implant may be subjected to biological corrosion. Uncoated implants can be...     

Vergleichende Korrosionsprüfung von dentalen Legierungen im Laborbioreaktor

Comparative corrosion test of dental alloys in a bioreactor The demands in the modern prosthetics require the insertion of ceramics, polymers, metals and composites in the oral cavity. To realise dental applications of ceramics and polymers intensive efforts was made in research and development in the last years. Nevertheless metallic materials possess one of the most important positions in biomedical engineering. The excellent biofunctionality of the metallic dental materials is responsible for this situation. One of the greatest disadvantages by integrating metallic materials in the human organism is the great susceptibility to corrosion in the biological environment. Experiments to describe the corrosion behaviour under simulated in-vivo conditions should be used to estimate the biocompatibility of the inserted biomaterials. The quality of the simulated biological environment defines the clinical relevance of these experiments. In this work a research team of the ?Thüringer Arbeitsgemeinschaft Biomaterial e.V.”? reports about corrosion experiments on precious and non-precious dental alloys in an in-vitro test system, which represents a new simulation equipment for the development of a artificial oral cavity.     

Oxidation in Air at 1400 K and Optical Properties of Inconel 625, FeCrAlloy and Kanthal Super ER

Oxidation of Metals - The materials used for the design of solar receivers are one of the critical parts of the concentrated solar power (CSP) plants. An increase in the working temperature of a...     

Selective synthesis and characterization of metallic cobalt, cobalt/platinum, and platinum microspheres

Metallic cobalt microspheres have been successfully synthesized via a facile hydrothermal method in the presence of poly (N-vinyl-2-pyrrolidone) (PVP), and the diameters of these spheres are in the range of 1-2 μm. Bimetallic Co/Pt microspheres and hollow noble metal Pt microspheres have also been selectively synthesized by adjusting the amount of reactants of replacement reaction in which corresponding noble metal compound and metallic cobalt microspheres are used as starting materials. The study on catalytic activities of the as-prepared metallic microspheres on hydrolysis of ammonia-borane for hydrogen generation reveals that Co/Pt (molar ratio 5:1) bimetallic microspheres are far more active than the hollow noble metal Pt microspheres.     

金属系牙科材料的应用现状及部分元素的毒副作用

本文对金属纱牙科材料的组成、性能，适用场合，存在问题及发展趋势进行了综合评述。认为汞、镍，铜，铝，铍，铬，钴，钒，钯元素均具有细胞毒性作用，在牙科材料及其它生物医学材料中应尽量避免使用；而元素钛、铌，锆，锡，钼，钽和铁是无毒性元素，可以作为改善生物医学材料力学性能，耐蚀性能及生物相容性的候选元素，为新型牙科合金材料及其它生物医学材料的开发研究提供选材依据。钛合金作为牙科材料是未来牙科材料的发展趋势     

Surface Characterization and Corrosion Resistance of Boron Nitride Coated Titanium Dental Implants

Protection of Metals and Physical Chemistry of Surfaces - Surface modifications of dental implants are of vital importance to enhance osseointegration and improve their corrosion resistance. This...     

Self-healing Coatings Loaded by Nano/microcapsules: A Review

Protection of Metals and Physical Chemistry of Surfaces - Coatings are applied on metallic surfaces to provide a dense barrier against the corrosive environment. However, coatings in most cases are...     

Hollow Twist Extrusion: Introduction,Strain Distribution,and Process Parameters Investigation

Metals and Materials International - Twist Extrusion is kind of severe plastic deformation process which enhances the strength of materials by applying a shear plastic strain and consequently grain...     

Metallic dental materials in patient's oral cavity acting as electrodes of electrochemical cells

The work was aimed at studying of standard potentials of commonly used metallic dental materials and determining of the effect of saliva conductivity and reaction on value of the potentials. The following materials have been examined: gold alloy (a material used for crowns and bridgeworks), chromium‐cobalt alloy (for frameworks in removable partial dentures), and silver amalgams (used for fillings) manufactured by three different companies. Taking into account that mucosa makes one of the electrodes existing in oral cavity the rest potentials of mucosa have been in vivo measured in several patients. Their values, converted with respect to NHE, oscillated within the range from + 0.31 V to + 0.47 V. Among metallic dental materials examined in the experiment maximal standard potential was found for the gold alloy, further materials having lower potentials, in decreasing order, were chromium‐cobalt alloy, and the amalgams Amalcap Plus, ANA 2000 and Septalloy. Significant differences between standard potentials of examined materials and mucosa indicate spontaneous formation of galvanic cells of electromotive force reaching even about 0.6 V.     

新型抗菌功能医用金属研究

不锈钢、钛及钛合金等医用金属材料已广泛应用于骨科、齿科及心血管介入等医疗领域,生物可降解镁合金是正在研究发展的新型医用金属材料,具有诱人的临床应用前景。面对目前『临床上亟待解决的植入物引发的细菌感染问题,开展医用金属材料的抗菌功能研究意义重大,也是实现金属材料结构／功能一体化发展的新探索。简要介绍了作者近年来在不锈钢、钛合金、可降解镁基金属等医用金属材料的抗菌功能研究方面的主要进展,并展望了抗菌医用金属材料的临床应用前景。     

The Effect of Zinc Oxide on the Physical and Mechanical Properties of Elastic Polymers

Protection of Metals and Physical Chemistry of Surfaces - The area of local inelasticity in latex elastic polymers filled and unfilled with zinc oxide powder in comparison with metallic zinc was...     

Evaluation of PEO Nanocomposite Coating on AZ31 Magnesium Alloy

Protection of Metals and Physical Chemistry of Surfaces - The synthesis of ceramic coatings via conversion of metallic surface is the main route of corrosion resistance in the magnesium alloys....     

An Investigation on the Tribological Behaviors of Al 6061–B4C Metal Matrix Composites

Protection of Metals and Physical Chemistry of Surfaces - Ceramic reinforcements are used in metal matrix composite materials to enhance the mechanical properties. Ceramic particles also improve...     

Analysis of Techniques for Improving the Adsorption Capacity of Talc

Protection of Metals and Physical Chemistry of Surfaces - Mineral adsorbents, such as talc, are materials that are abundant in nature and used as scavengers, binding agents, fillers, etc....     

Failure of a Ti-Based Metallic Glass Matrix Composite Upon High-Temperature Annealing

Metals and Materials International - The preparation of metallic glass matrix composites (MGMCs) requires rapid cooling rate under vacuum conditions, and the amorphous matrix is sensitive to high...