Novel advanced ceramic and coating processing
The modern ceramic industry needs the development and implementation of new materials and innovative processing methods in order to improve the quality and reliability of ceramic products, to increase manufacturing efficiency, and to provide opportunities to use advanced materials in the next generation of technologies and devices. It is well known that the properties and performance of ceramics and coatings strongly depend on the processing route and their features. Dedicated research and development of advanced technologies and their optimisation should enable improvements to materials performance. This is particularly important when advanced ceramic components are produced on an industrial scale. At the same time, new or improved advanced technologies may allow materials and components with unique properties to be developed, which could not be obtained using older conventional processing routes.
This special issue of Advances in Applied Ceramics is dedicated to novel processing of advanced ceramics and coatings, as well as to the research and optimisation of earlier developed processing routes that improve the productivity and quality of ceramic materials. The issue contains a number of articles commissioned from well-recognised ceramic specialists from both academia and industry. Along with the interesting innovative processing solutions presented, which were developed in academia, this special issue also contains the results of the development and implementation of advanced technologies into the ceramic industry, including the results of the commercial manufacturing of advanced ceramics. Articles have been selected to cover different aspects of ceramic technology, such as colloidal processing; preparation and use of specially prepared ceramic powders and precursors; forming routes of different ceramic products (both solid components and coatings) for variety of applications; sintering; studies of the influence of processing on structure and properties of the ceramics; and large-scale manufacturing. The research in some of the selected articles has been presented at international ceramic conferences, but some articles describe absolutely new results.
The review of colloidal processing of ceramic materials by MorenoCitation1 will be of interest to many ceramic specialists because colloidal processing is one of the key aspects of practically all types of ceramics and coatings manufacturing. Understanding of colloidal processing allows manufacturing to be managed properly in order to achieve highly reliable products. The paper presented by Stuer and BowenCitation2 demonstrates the application of new technical solutions in colloidal processing of alumina and freeze granulation for manufacturing of transparent ceramics through the dry pressing route.
The studies conducted by Finoli et al.Citation3 were dedicated to development of processing of multi-scale porous structures for in vitro culturing of human stem cells. Lin et al.Citation4 has presented an article on the application of an innovative technological solution in the formation of porous hydroxyapatite. The solution allowed material with micro-channel controlled structures with elevated strength to be obtained, and the use of free pressureless spark plasma sintering significantly reduced the processing cycle and improved the uniformity of the ceramics. These results are important for the processing of bioactive ceramics for biomedical applications because conventionally processed hydroxyapatite ceramics with randomly distributed pores do not have high mechanical properties, which restricts the use of these ceramics. The development of zirconia nanoceramics using a new preparation route of specially coated nanoparticles and Yb2O3 as the dopant allowed materials with increased mechanical properties to be obtained.Citation5 These ceramics may be used as structural engineering components for industrial applications, and also for biomedical applications as bioinert components where superior mechanical properties and inertness are required.
Spark plasma sintering is a relatively new method that successfully competes with hot pressing due to significantly faster processing cycles, and this method has attracted many researchers in recent years. The article by Chaim et al.Citation6 is devoted to the mechanism of spark plasma sintering, particularly for nanoceramics. The authors consider the processes occurring at different stages of the sintering process with emphasis on the preservation of nanocrystalline structures.
The processing of ceramic–metal composites was reviewed by TravitzkyCitation7 which considers the non-reactive and reactive infiltration processes. In order to obtain composites with near-net complex shapes, which have manufacturing difficulties, the additive manufacturing technology developed by the author, i.e. laminated object manufacturing and three-dimensional printing, can be combined with the infiltration technique.
The results of the development of reaction-bonded boron carbide ceramics designated for armour applications were reviewed by Dariel and Frage.Citation8 Based on their extensive experimental work, the authors considered the influence of different technological factors on structure, phase composition and mechanical properties of the ceramics.
Manufacturing of large-size ceramic components with high wear-, corrosion- and thermal shock-resistance is important for mining, mineral, petrochemical and power generation industrial processing applications. The article by MedvedovskiCitation9 demonstrated the results of the development and commercial manufacturing of SiC-based ceramic monolithic components with large sizes and complex shapes, which were produced using the thixotropic casting technology. The produced industrial components, which cannot be obtained by other more conventional technologies, have high reliability.
High performance nano-scale glass–ceramic beads were obtained in the system of Al2O3–La2O3–ZrO2 by Rosenflanz et al.Citation10 The authors achieved a material performance similar to sapphire by optimising the composition and using the glass crystallisation process. Manufacturing of these beads are currently in the industrial stage.
The low pressure injection moulding technology that allows ceramic components with near-net shapes to be produced was reviewed from the large-scale manufacturing experience by Medvedovski and Peltsman.Citation11 In this article the influence of processing parameters on the performance, processing yield and productivity of ceramic components was considered. The paper also describes the manufacturing equipment for low pressure injection moulding.
Electrophoretic deposition may be successfully used for producing different types of functional materials with custom-design properties. This technology is especially useful for coating processes of different electroceramics, fuel cells, batteries and other functional components. Ata and ZhitomirskyCitation12 presented the results of the development of Electrophoretic deposition technology for preparation of MnO2 nanostructured films using new organic acid-type special dispersants. This applied technological solution based on the found dispersant allowed to improve performance of the functional ceramics, such as, supercapacitors.
Research on superconductive ceramics YBCO has attracted ceramic researchers and users for more than two decades. However, due to the difficulties in the solid ceramic wire manufacturing, the HTS ceramics are not yet widely used. The paper presented by RokhvargerCitation13 demonstrates the possibility to obtain HTS ceramic coatings on the wires with high performance.
The influence of processing parameters on structure and dielectric properties of BaTiO3 ceramics with an Ho2O3 dopant was studied by Mitic et al.Citation14 Applying a fractal method for integral contacts analysis and using the microstructural examinations, the authors proposed mathematical modelling of the grain structures of the BaTiO3 ceramics.
This issue builds on the history of processing research published in the journal. Readers interested are advised to read selected past articles on shaping of porous alumina bodies by freeze casting;Citation15 consolidation of ceramic nanopowders;Citation16 strong ceramic foams from polyurethane templates;Citation17 dispersion and rheological behaviour of SiC tape casting slurry;Citation18 injection moulding of thin walled zirconia tubes for oxygen sensors;Citation19 and a review on sintering and densification of nanocrystalline ceramic oxide powders.Citation20 There is also a body of work on biomaterials processing: synthesis and characterisation of gelatine–nanohydroxyapatite composite scaffolds for bone tissue engineering;Citation21 bioactive glass and hybrid scaffolds prepared by sol–gel method for bone tissue engineering;Citation22 tubular hydroxyapatite scaffolds;Citation23 and nature inspired novel processing routes for ceramic foams.Citation24
As a guest editor, I am grateful to all authors who contributed to this special issue of Advances in Applied Ceramics and their efforts to prepare the manuscripts in time. I am also grateful to all reviewers for their work and advice, which definitely helped to improve the papers for publication. I hope that this special issue will be interesting and useful for many ceramic specialists from academia and industry who work with the development of advanced ceramics and coatings and in manufacturing, as well as specialists who use advanced ceramics in modern devices and technologies.
Eugene Medvedovski
Guest editor
Umicore Thin Film Products
References
- Moreno R: ‘Colloidal processing of ceramics and composites’, Adv. Appl. Ceram., 2012, 111, (5–6), 246–253.
- Stuer M, Bowen P: ‘Yield stress modeling of doped alumina suspensions for applications in freeze granulation: towards dry pressed transparent ceramics’, Adv. Appl. Ceram., 2012, 111, (5–6), 254–261.
- Finoli A, Ostrowski N, Schmelzer E, Nettleship I, Gerlach J: ‘Multiscale porous ceramic scaffolds for in-vitro culturing of primary human cells’, Adv. Appl. Ceram., 2012, 111, (5–6), 262–268.
- Lin Y.-S, Meyers MA, Olevsky EA: ‘Micro-channeled hydroxyapatite composents by sequential freeze drying and free pressureless spark-plasms sintering’, Adv. Appl. Ceram., 2012, 111, (5–6), 269–274.
- Kern F, Gadow R: ‘2·25 mol-% ytterbia stabilized zirconia (Yb-TZP) manufactured from coated nanopowder’, Adv. Appl. Ceram., 2012, 111, (5–6), 275–279.
- Chaim R, Marder R, Estournes C, Shen Z: ‘Densification and preservation of the ceramic nanocrystalline character by spark plasma sintering’, Adv. Appl. Ceram., 2012, 111, (5–6), 280–285.
- Travitzky N: ‘Processing of ceramic-metal composites’, Adv. Appl. Ceram., 2012, 111, (5–6), 286–300.
- Dariel MP, Frage N: ‘Reaction bonded boron carbide: recent developments’, Adv. Appl. Ceram., 2012, 111, (5–6), 301–310.
- Medvedovski E: ‘Large-sized SiC-based wear-, corrosion- and themal shock- resistant ceramics produced by thixotropic casting technology’, Adv. Appl. Ceram., 2012, 111, (5–6), 311–322.
- Rosenflanz A, Tangeman J, Anderson T: ‘On the processing and properties of liquid phase derived glass-ceramics in the Al2O3-La2O3-ZrO2 system’, Adv. Appl. Ceram., 2012, 111, (5–6), 323–332.
- Medvedovski E, Peltsman M: ‘Low pressure injection moulding mass-production technology of complex-shape advanced ceramic components’, Adv. Appl. Ceram., 2012, 111, (5–6), 333–344.
- Ata MS, Zhitomirsky I: ‘Electrophoretic nanotechnology of ceramic films’, Adv. Appl. Ceram., 2012, 111, (5–6), 345–350.
- Rokhvarger A: ‘Cost-effective and reliable electric wire filaments coated with nanofabricated and sintered superconductive ceramics’, Adv. Appl. Ceram., 2012, 111, (5–6), 351–359.
- Mitic VV, Paunovic V, Purenovic J, Kocic JK, Pavlovic V: ‘The processing parameters influence on BaTiO3-ceramics fractal microstructure and dielectric characteristics’, Adv. Appl. Ceram., 2012, 111, (5–6), 360–366.
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- Luyten J, Thijs I, Vandermeulen W, Mullens S, Wallaeys B, Mortlemans R: ‘Strong ceramic foams from polyurethane templates’, Adv. Appl. Ceram., 2005, 104, (1), 4–8.
- Vasanthakumari KG, Natarajan R: ‘Dispersion and rheological behaviour of SiC tape casting slurry’, Adv. Appl. Ceram., 2005, 104, (2), 73–78.
- Soykan HS, Karakas Y: ‘Injection moulding of thin walled zirconia tubes for oxygen sensors’, Adv. Appl. Ceram., 2005, 104, (6), 285–290.
- Chaim R, Levin M, Shlayer A, Estournes C: ‘Sintering and densification of nanocrystalline ceramic oxide powders: a review’, Adv. Appl. Ceram., 2008, 107, (3), 159–169.
- Mobini S, Javadpour J, Hosseinalipour M, Ghazi-Khansari M, Khavandi A, Rezaie HR: ‘Synthesis and characterisation of gelatin-nano hydroxyapatite composite scaffolds for bone tissue engineering’, Adv. Appl. Ceram., 2008, 107, (1), 4–8.
- Pereira MM, Jones JR, Hench LL: ‘Bioactive glass and hybrid scaffolds prepared by sol-gel method for bone tissue engineering’, Adv. Appl. Ceram., 2005, 104, (1), 35–42.
- de Sousa FCG, Evans JRG: ‘Tubular hydroxyapatite scaffolds’, Adv. Appl. Ceram., 2005, 104, (1), 30–34.
- Dhara S, Pradhan M, Ghosh D, Bhargava P: ‘Nature inspired novel processing routes for ceramic foams’, Adv. Appl. Ceram., 2005, 104, (1), 9–21.