Objective
The main goal of this project is to examine whether the coatings of current carbon fibres are fully adapted to the thermostable resins (bismaleimides) used for medium-range temperature structural applications.
The aim of the project is to increase the frequency range for which piezoceramics can replace single crystals in bulk and surface acoustic wave (SAW) devices. Piezoceramics offer advantages over single crystals such as tailoring of properties through changes in chemical composition and relative ease of fabrication. However, at present, their use is limited to frequencies below 20 MHz for bulk devices due to the low mechanical strength 0.05 to 0.1 mm thick samples and to the coarse grain structure which leads to inhomogeneous properties in this thickness range. For SAW devices coarse grains lead to high propagation losses and limit their use to less than 100 MHz.
A number of ways to obtain fine grain and high density ceramics were investigated. It was shown that this could be achieved by hydrothermal synthesis of lead titanate leading to grain size of less than 1 um, or milling a mixed oxide powder for a longer time, followed by reducing the sintering temperature leading to PZT ceramics with grain size of less than 2 um.
Using a postsinter hot isostatic pressing (HIP) process it was possible to reduce the porosity to less than 1% and as low as 0.1% was achieved by optimizing the HIP conditions. The reduction in porosity was accompanied by an improvement in the dielectric and piezoelectric properties.
The surface acoustic wave (SAW) properties of various ceramics were measured. PZT materials have good SAW properties, but only their high propagation losses limit them to < 30 MHz. Modified lead titanate compositions have better temperature stability and lower propagation loss, making them suitable for devices in the range 20-150 MHz. The properties were further improved through compositional studies and by producing fine grained, high density materials. In addition, ceramics prepared from hydrothermal powders had improved SAW properties compared to the same composition prepared by the mixed oxide process.
The fine grained ceramics allowed higher frequency bulk devices to be obtained. This was demonstrated in 2 devices, a 15 MHz focused transducer, which gave improved axial resolution, and a linear array in which finer structure allowed an operating frequency of 20 MHz to be achieved.
The development of these new materials will allow the extension of product ranges and increase competitiveness on the world market.
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 coating and films
- 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)
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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.
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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.
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Coordinator
2950 KVISTGARD
Denmark
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.