Objective
One of the major objectives of research into advanced structural ceramic materials is to achieve a sufficient degree of toughness, strength, thermal shock resistance and mechanical shock resistance and corrosion resistance so that the beneficial aspects of ceramics such as low density and high melting point, can be exploited in the design of critical high temperature components. The aim of this project is to improve the mechanical properties of ceramic materials, especially at elevated temperatures, and their resistance to corrosion by incorporating ultrafine particles of metals with high melting points in a ceramic matrix based on aluminium oxide and zirconium oxide. Theproduction and the incorporation of the metals in an extremely finely divided form calls for a special manufacturing technology.
Colloidal metal particles in the range of nm (rhodium, pallidium, platinum, molybdenum) could be deposited onto ceramic powder by a special manufacturing technique. Aluminium oxide and zirconium oxide based composites with a homogeneous, finely divided metallic phase up to 5 mass % were produced via the combined sinter hot isostatic pressing (HIP) technique. These materials show fracture toughness and flexural strength improvements of up to 25%, high corrosion resistance in molten metals, glass melt, and hydrofluoric acid and improved thermal shock resistance.
Studies on the production of ceramic metal composites have included the production of intimate arrangements of metallic and ceramic particles and the conversion of these to fully dense bodies using combined sinter hot isostatic pressing (HIP). Key targets were increases in fracture toughness and in flexural strength of the metal reinforced ceramic materials.
Even at low concentrations of noble metals significant effects were observed on the sintering to a cubic structure of yttria stabilised zirconia. The densification to pore free materials was hindered, with this effect being worsened with increasing metal loading. The same observation was rue for alumina zirconia mixed oxide ceramics. Palladium additions were found to be the least detrimental.
In all samples, where metal has been introduced from a sol, large metal lakes were found in the structure of the sintered material. These were probably attributable to the formation of agglomerates of the fine metallic particles during the deposition of the metal. Nevertheless, the samples of alumina zirconia mixture with palladium exhibited improved flexural strength over the metal free reference samples. The formation of large metal lakes can be prevented by using direct deposition of the metal without prior formation of a sol.
Samples containing metallic molybdenum sintered better than metal free samples and flexural strength and fracture toughness were increased by 20-25%. Samples containing 1% molybdenum and 1% palladium showed slight improvements in thermal shock resistance and the 1% palladium samples showed considerably improved resistance to hydrofluoric acid. Corrosion investigations also indicated improvements over the metal free materials.
The improvements in properties, aimed for at the beginning, have been largely attained but could not be achieved in a single ceramic metal composite material since improvements were always counterbalanced by detrimental effects on other properties.
ONE OF THE MAJOR OBJECTIVES OF RESEARCH INTO ADVANCED STRUCTURAL CERAMIC MATERIALS IS TO ACHIEVE A SUFFICIENT DEGREE OF TOUGHNESS, STRENGTH, THERMAL AND MECHANICAL SHOCK RESISTANCE AND CORROSION RESISTANCE SO THAT THE BENIFICIAL ASPECTS OF CERAMICS SUCH AS LOW DENSITY AND HIGH MELTING POINT CAN BE EXPLOITED IN THE DESIGN OF CRITICAL HIGH TEMPERATURE COMPONENTS.
SILICON NITRIDE, ALUMINA, ZIRCONIA AND ALLOYS OF THESE OXIDES ARE CURRENTLY CONSIDERED TO BE PRIMARY CONTENDERS FOR THE FUTURE DEVELOPMENT OF HIGH TECHNOLOGY ENGINEERING CERAMICS, AND MUCH WORK HAS ALREADY BEEN CARRIED OUT ON THESE MATERIALS TO IMPROVE THEIR MECHANICAL AND TRIBOLOGICAL PROPERTIES BY COMPOSITIONAL AND MICROSTRUCTURAL MODIFICATION.
THE AIM OF THIS PROJECT IS TO IMPROVE THE MECHANICAL PROPERTIES OF CERAMIC MATERIALS, ESPECIALLY AT ELEVATED TEMPERATURES, AND THEIR RESISTANCE TO CORROSION BY INCORPORATING FINEST PARTICLES OF METALS WITH HIGH MELTING POINTS IN A CERAMIC MATRIX BASED ON AL2O3, ZRO2 AND SI3N4.
THE PRODUCTION AND THE INCORPORATION OF THE METALS IN AN EXTREMELY FINELY DIVIDED FORM CALLS FOR A SPECIAL MANUFACTURING TECHNOLOGY.
THE EXTREMELY FINE METALS CAN BE ACHIEVED BY PRODUCING COLLOIDAL METAL SOLS. THE SOLS HAVE A NARROW GRAIN SIZE DISTRIBUTION OF 5-20 NANOMETRES. INITIAL PROBLEMS, RELATING TO THE DEPOSITION OF THE SOLS ONTO THE CERAMIC SUBSTRATES WHICH CAUSED MICROMETRE-SIZED METAL-LAKES IN THE SINTERED PRODUCTS, COULD BE IMPROVED BY A NEW TECHNOLOGY. THIS IS THE ENCAPSULATION OF SOLS AND ALLOY SOLS WITH OTHER METALS OR CERAMIC MATERIALS.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
- agricultural sciences agriculture, forestry, and fisheries agriculture grains and oilseeds
- engineering and technology materials engineering composites
- natural sciences chemical sciences inorganic chemistry transition metals
- natural sciences chemical sciences inorganic chemistry post-transition metals
- engineering and technology materials engineering ceramics
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Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
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Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
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Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
45145 Essen
Germany
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.