Periodic Reporting for period 2 - CEM-WAVE (Novel Ceramic Matrix Composites produced with Microwave assisted Chemical Vapour Infiltration process for energy-intensive industries)
Período documentado: 2021-10-01 hasta 2023-03-31
This novel process is based on a Microwave-assisted Chemical Vapor Infiltration (MW-CVI) process implemented with the latest MW solid-state sources as an economic and sustainable alternative to reduce the processing costs of CMCs components. To validate the MW-CVI process, a CMC-based prototype will be developed and tested within a pilot-scale radiant tube furnace in an active steelmaking plant. This prototype is a future candidate to replace the metallic materials currently employed in steelmaking, particularly considering the upcoming gradual transition to renewable energy sources (i.e. hydrogen).
The CEM-WAVE project answers the European market growing need for novel materials that can withstand the fluctuating and harsh energy conditions created while using renewable sources. In this sense, it supports the ambitious strategic plan set by the European Green Deal.
Among others, CEM-WAVE’s most important objectives include:
- Improving energy efficiencies in steelmaking production up to 30%, with a reduction in costs ranging between 7 and 13% given the higher thermomechanical performance of CMC materials;
- Reducing the process CO2 emissions up to 20% per kg of CMCs produced;
- Improving the lifetime of radiant tube furnaces of up to 20% compared to the current average, which is between 4 and 8 years.
At first, processing parameters for the interphase deposition (T1.1 - T1.2) were defined by FHF to manufacture the CMC preforms, being such component critical to guarantee the characteristic pseudo-ductile fracture behaviour of CMC materials. Following, the production and stabilization of the preforms with the selected geometries of interest for the CEM-WAVE project have been carried out. In our case, a plate-shaped geometry was selected as ideal for the various thermo-mechanical characterizations and joining activities while tubular-shaped samples were developed in view of the production of the CEM-WAVE project demonstrator (T1.3).
In parallel, IPCF-CNR measured the high-temperature dielectric properties for both the non-oxide and oxide-based CMC preforms at the initial stage (T2.1). Such measurements were also employed in the electromagnetic modelling of the MW-CVI loaded reactors to determine the operating frequencies and modes that could provide the most uniform heating of the samples of interest (T2.2). Moreover, first solid-state sources have been realized to be integrated into the MW-CVI reactors using coupling systems to ensure high coupling levels (-10 dB or higher) at the operating conditions of the loaded cavities (T2.3).
The first results obtained during the MW heating trials performed at UNIPI using three interim solid-state sources (able to each emit 500 W power and tunable in the whole 2.4-2.5 GHz ISM frequency band) showed significant improvements with respect to the magnetron sources previously employed for similar processes (T3.1). A multiport configuration scheme, where each source operating frequency has been selected based on the results obtained from T2.2 has been efficiently employed to optimize the preform heating pattern, minimizing the cross-coupling between the various sources and without any plasma occurrence in the cavity.
The first tasks performed within WP5 by CNRS involved the collection of several micrographs to be used for the micro/macro-scale modelling of the MW-CVI processes. Within T6.1 of WP6, first experimental activities focused on the selection of the most suitable joint materials candidates and processing technologies for the CEM-WAVE preforms. POLITO obtained promising results using glass-ceramic as joining material in the case of oxide-oxide CMCs and refractory metals (RMs) silicides, dispersed in a silicon matrix, for non-oxide CMCs.
In parallel with CEM-WAVE’s technical activities, the business models to maximize the impact of the project results are being elaborated. This activity is performed in collaboration with the members of the advisory board and other relevant stakeholders. A wide dissemination activity is being planned for the project, although the issue of several conferences, workshops and other relevant presential events being cancelled, has so far limited this activity to the online sphere, only.
One of the most important improvements the CEM-WAVE project can bring to the state-of-the-art in the MW-CVI technology is the shift from the fixed-frequency emission magnetron sources to the fully tunable solid-state sources. The latter are still limited to low power applications but are envisioned to replace magnetron sources in the near future. This is thanks to their reduced form factor, low operating voltage, reliability, lifetime, and especially their ability to precisely control phase and frequency, achieving better heat distributions than it is currently possible using conventional magnetrons.
Indeed, the CEM-WAVE’s project is currently proving that MW solid-state sources can provide several unexplored possibilities in terms of tailoring and automatic control of the sample heating compared to conventionally used magnetron sources, increasing both the energy and chemical efficiency of the MW-CVI process as well as decreasing its environmental impact.
Considering that CEM-WAVE project pursues the reduction of energy consumption and CO2 emissions both in CMCs production and in its adoption within steelmaking industrial processes and beyond, its main objectives contribute to the overall goal set by the European Green Deal towards net-zero emissions. In addition, CEM-WAVE’s results are expected to meet new market opportunities for those European enterprises focused on enhancing and modernizing manufacturing capacities in the Union, while shifting to green energy sources. This, in turn, will contribute to creating new jobs, both in the short and medium-term.