Fibrous porous mullite ceramics modified by mullite whiskers for thermal insulation and sound absorption

Ultrastrong and High Thermal Insulating Porous High‐Entropy Ceramics up to 2000 °C

“…With the increase of temperature to 2000 °C (Figure 4d), the strength of the samples is slightly reduced (102 MPa at 10% strain and 692 MPa at 49% strain); additionally, the stress-strain curve becomes smoother (the zigzag has disappeared), demonstrating Weibull distribution regarding the compressive strength of tested samples at a porosity range of 45-55%. c) Strength versus porosity of the 9HEB samples compared to the reported porous ceramics, such as SiC, [3,15,[30][31][32][33] mullite, [34][35][36][37][38] Si 3 N 4 -SiC, [39] Si 3 N 4 , [40] Al 2 O 3 , [41] SiO 2 , [42,43] ZrB 2 -SiC, [44,45] 𝛾-Y 2 Si 2 O 7 , [46,47] ZrC, [48,50] ZrC-SiC, [49] HfC, [50] AlN, [51] SiOC, [52] Anorthite, [53] and ZrO 2 -Al 2 O 3 . [8] d) In situ compressive stress-strain curves of the samples at elevated temperatures.…”

“…b)Weibull distribution regarding the compressive strength of tested samples at a porosity range of 45-55%. c) Strength versus porosity of the 9HEB samples compared to the reported porous ceramics, such as SiC,[3,15,[30][31][32][33] mullite,[34][35][36][37][38] Si 3 N 4 -SiC,[39] Si 3 N 4 ,[40] Al 2 O 3 ,[41] SiO 2 ,[42,43] ZrB 2 -SiC,[44,45] 𝛾-Y 2 Si 2 O 7 ,[46,47] ZrC,[48,50] ZrC-SiC,[49] HfC,[50] AlN,[51] SiOC,[52] Anorthite,[53] and ZrO 2 -Al 2 O 3 [8]. d) In situ compressive stress-strain curves of the samples at elevated temperatures.…”

Analysis of Influencing Factors in the Preparation of Mullite Whiskers from Recovering Silicon-Rich Waste under Low-Temperature Conditions

“…The crystallographic direction parallel to the c-axis, in which mullite crystals grow much faster than in other directions, is advantageous for the synthesis of mullite whiskers with a high degree of orientation [ 7 , 8 ]. Moreover, the fact that mullite is formed by dissolution-precipitation, which is rare under natural conditions, leads to the common synthesis of mullite whiskers by artificial means [ 9 , 10 ]. Based on the above principles, most researchers have prepared mullite whiskers by adding an excess of single transition metal oxides as catalysts, such as WO 3 [ 11 ], MoO 3 [ 12 ], V 2 O 5 [ 13 ], P 2 O 5 [ 14 ], B 2 O 3 [ 15 ], etc.…”

“…Nowadays, it is still the trend to develop mullite industrialization by recycling industrial waste, such as recycling industrial aluminum slag [ 22 , 23 ], fly ash [ 24 , 25 ], industrial gangue [ 26 , 27 ], and photovoltaic silicon waste [ 28 , 29 ] to produce mullite whiskers. Deng et al [ 9 ] prepared mullite-whisker-reinforced lightweight porous materials using fly ash and calcined bauxite as raw materials and AlF 3 ·3H 2 O as an additive using the particle stabilization method. Li et al [ 30 ] prepared self-reinforced porous mullite ceramics using fly ash, different aluminum sources (Al(OH) 3 and Al 2 O 3 ) and additive AlF 3 as raw materials using the starch consolidation method.…”

Co‐optimizing compressive and heat‐insulation properties of rigid fibrous ceramics by compositing with phenolic aerogel

“…Up till now, considerable efforts have been made to enhance the mechanical properties of RFC, where optimizing preparation technology is the most common approach employed. The preparation parameters such as fiber aspect ratio, 9 fiber content, 10,11 whisker modification, 12 binder species, 13 etc., have been systematically studied. However, the improvement of the mechanical properties of RFC by these methodologies is limited and cannot alter the nature of the poor mechanical properties due to the high porosity.…”