Formation at low temperature with low shrinkage of polymer/Al/Al2O3 derived mullite

Michalet, Thibaut; Parlier, M.; Addad, Ahmed; Duclos, R.; Crampon, J.

doi:10.1016/s0272-8842(00)00082-1

Cited by 13 publications

(9 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present work, we investigated the crystallization kinetics of mullite produced using a novel synthesis method, based on γ‐alumina nanoparticles and a silicone resin, proposed recently by Bernardo et al 22 This approach has several technological advantages over sol–gel‐based precursors, as preceramic polymers can be easily shaped using conventional plastic‐forming technologies, do not have any drying problems that hamper the possibility of fabricating bulk components, and do not require any specialized handling procedures 23–25 . Other researchers studied the formation of mullite starting from a silicone resin and various fillers (α‐alumina and/or metallic Al), 26–29 but they were unable to obtain phase‐pure mullite at low temperatures. The aim of our work was to demonstrate, for the first time, that the addition of nanosized fillers to preceramic polymers is an uniquely suitable method for the production of advanced ceramics at a low temperature with a very favorable kinetics and a high degree of microstructural control on the crystalline phase assemblage.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Studies of Mullite Synthesis from Alumina Nanoparticles and a Preceramic Polymer

Griggio

Bernardo

Colombo

et al. 2008

Journal of the American Ceramic Society

View full text Add to dashboard Cite

The crystallization kinetics of mullite formation in a diphasic precursor consisting of a silicone resin filled with commercial c-alumina nanoparticles (15 nm mean particle size, specific surface area of 100 m 2 /g), heated in air from 12501 to 13501C, was studied by X-ray diffraction. Transitional c-alumina and amorphous silica from the pyrolysis of the preceramic polymer exhibited a remarkable reactivity, as demonstrated by a very low incubation time (from 500 s at 12501C to 20 s at 13501C), a high mullite yield (about 80 vol%, after 100 s at 13501C), and a low activation energy for nucleation (677760 kJ/mol). The activation energy values found were lower than those reported previously for other diphasic systems, including sol-gel precursors. Besides the high specific surface of nanosized c-alumina particles, the low energy barrier could be attributed to the highly reactive silica deriving from the oxidation of Si-CH 3 bonds in the silicone and to the homogeneous dispersion of the nanosized filler inside the preceramic polymer. Furthermore, the possibility of applying plastic shaping processing methods to the mixture of a preceramic polymer and nanosized filler makes this approach particularly valuable, in comparison, for instance, with sol-gel based alternatives.

show abstract

Section: Introductionmentioning

confidence: 99%

Kinetic Studies of Mullite Synthesis from Alumina Nanoparticles and a Preceramic Polymer

Griggio

Bernardo

Colombo

et al. 2008

Journal of the American Ceramic Society

View full text Add to dashboard Cite

show abstract

“…The sol–gel processing, in addition, may allow the formation of secondary phases, giving the opportunity of producing mullite‐based nanocomposites, as pointed out by Sorarù et al ., 17 with the formation of SiC within the mullite crystals. Recent work pointed out the feasibility of the production of mullite compacts from preceramic polymers, consisting of polysiloxanes, as the source for silica, filled with Al 2 O 3 and Al particles 30–33 . The general advantages of preceramic polymers are the low processing temperatures and, above all, the possibility of using polymer‐processing techniques, allowing to obtain complex shapes.…”

Section: Introductionmentioning

confidence: 99%

“…However, the addition of secondary, filler materials (which can either react with the preceramic precursor or remain inert during firing) allows the production of ceramic monoliths with a good structural integrity upon heat treatment 37,38 . The preceramic polymer–alumina (or aluminum) reaction (aided by an oxidative atmosphere that transforms the polysiloxanes into highly reactive SiO 2 ) is thus a promising way to obtain mullite, as illustrated in the experiments of Suttor et al ., 30 Michalet et al ., 31,32 and Anggono et al ., 33 even if their experiments showed that complete mullitization was obtained only when firing in air well above 1500°C.…”

Section: Introductionmentioning

confidence: 99%

Novel Mullite Synthesis Based on Alumina Nanoparticles and a Preceramic Polymer

Bernardo

Colombo

Pippel

et al. 2006

Journal of the American Ceramic Society

View full text Add to dashboard Cite

Heating in air of a selected mixture of a silicone resin and alumina nanoparticles in the temperature range 1200°–1500°C yielded dense, crack‐free mullite samples. Al2O3, due to its nanometric size, proved to be very reactive toward silica, deriving from the ceramization of the preceramic polymer, leading to the formation of a large volume fraction of mullite crystals even at low firing temperatures (1250°C). Because of the homogeneity of the distribution of alumina nanoparticles in the starting system, the ceramized samples exhibited a very fine microstructure consisting of crystals with an average dimension in the range of 50–300 nm.

show abstract

“…[11][12][13][14][15][16][17] More homogenous porous mullite ceramics with complex shapes can possibly fabricated by this technique. Furthermore, only moderate processing temperature is needed due to the high reactivity of amorphous SiO 2 yielded by silicone resin.…”

Section: Introductionmentioning

confidence: 99%

Porous mullite ceramics fabricated by co-pyrolysis alumina powders filled silicone resin

Peng

Duan

et al. 2014

Materials Research Innovations

View full text Add to dashboard Cite

Nanoporous mullite ceramics were fabricated by pyrolysis of micron alumina powders filled with silicone resin. The mixture of silicone resin and micron c-Al 2 O 3 began transforming to mullite at 1250uC in air, and could be entirely transformed to mullite when the pyrolysis temperature exceeded 1300uC. The effect of shaping pressure on microstructure and mechanical property of the porous mullite ceramics was investigated. The experimental results showed that the porosity and flexural strength can be easily tuned by changing shaping pressure. Both of the open porosity and average pores size of the obtained samples decreased at elevated shaping pressure. With a shaping pressure of 65 MPa, nanoporous mullite ceramics with an average pore size of 32 nm can be obtained, showing 23?5% in open porosity and 50 MPa in flexural strength. Interestingly, the microstructure of porous mullite ceramics consisted of loose region and dense region for the most possible reason that the Al 2 O 3 powders were un-homogeneously distributed in silicone resin.

show abstract

Formation at low temperature with low shrinkage of polymer/Al/Al2O3 derived mullite

Cited by 13 publications

References 18 publications

Kinetic Studies of Mullite Synthesis from Alumina Nanoparticles and a Preceramic Polymer

Kinetic Studies of Mullite Synthesis from Alumina Nanoparticles and a Preceramic Polymer

Novel Mullite Synthesis Based on Alumina Nanoparticles and a Preceramic Polymer

Porous mullite ceramics fabricated by co-pyrolysis alumina powders filled silicone resin

Contact Info

Product

Resources

About