scholarly journals Micro‐/nanostructure evolution of C/SiFeO(N,C) polymer‐derived ceramic papers pyrolyzed in reactive ammonia atmosphere

2021 ◽  
Author(s):  
Johannes Peter ◽  
Alexander Ott ◽  
Ralf Riedel ◽  
Emanuel Ionescu ◽  
Hans‐Joachim Kleebe
Keyword(s):  
Polymer Derived Ceramic ◽  
Ammonia Atmosphere

scholarly journals Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO2 Removal

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3276
Author(s):  
Aitana Tamayo ◽  
Juan Rubio ◽  
Fausto Rubio ◽  
Mᵃ Angeles Rodriguez
Keyword(s):  
Structural Characteristics ◽  
Domain Size ◽  
Ceramic Composites ◽  
Silicon Oxycarbide ◽  
Crosslinking Degree ◽  
Molecular Precursors ◽  
Textural Characterization ◽  
Polymer Derived Ceramic ◽  
Ultimate Properties ◽  
Lower Carbon

Silicon oxycarbide ceramers containing 5% aluminum, zirconium, and cobalt with respect to the total Si amount are prepared from a commercial polysiloxane and molecular precursors and pyrolyzed at temperatures ranging from 500 to 1000 °C. HF etching is carried out to partially digest the silica phase, thus revealing structural characteristics of the materials, which depend upon the incorporated heteroatom. From the structural and textural characterization, it was deduced that when Al enters into the ceramer structure, the crosslinking degree is increased, leading to lower carbon domain size and carbon incorporation as well. On the contrary, the substitution by Zr induced a phase-separated SiO2-ZrO2 network with some degree of mesoporosity even at high pyrolysis temperatures. Co, however, forms small carbidic crystallites, which strongly modifies the carbonaceous phase in such a way that even when it is added in a small amount and in combination with other heteroatoms, this transient metal dominates the structural characteristics of the ceramer material. This systematic study of the ceramer compounds allows the identification of the ultimate properties of the polymer-derived ceramic composites.

Polymer derived ceramic aerogels

2021 ◽  
Vol 25 (4) ◽  
pp. 100936
Author(s):  
Cekdar Vakifahmetoglu ◽  
Tugce Semerci ◽  
Aleksander Gurlo ◽  
Gian Domenico Soraru
Keyword(s):  
Polymer Derived Ceramic

Effects of Sintering Conditions on Properties of a Warm Compacted Stainless Steel Powder

2012 ◽  
Vol 217-219 ◽  
pp. 483-486
Author(s):  
Mei Yuan Ke
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Sintered Density ◽  
Sintering Temperature ◽  
Steel Powder ◽  
Stainless Steel Powder ◽  
Sintering Atmosphere ◽  
Comprehensive Properties ◽  
Ammonia Atmosphere ◽  
Sintering Conditions

Effects of Sintering atmosphere and temperature on properties of warm compacted 410L stainless steel powder were studied. Sintered density, hardness, tensile strength and elongation were measured. Results showed that in order to achieve high comprehensive properties, the optimal sintering temperature was 1230°C for 410L stainless steel powder. At the same sintering temperature, density and hardness sintered in vacuum were much higher than that sintered in cracked ammonia while tensile strength sintered in cracked ammonia were much higher than that in vacuum. When sintered in vacuum at 1230°C, sintered density was 7.45 g•cm-3, hardness was 65 HRB, tensile strength was 410 MPa and elongation was 29.5%. When sintered in cracked ammonia atmosphere at 1230°C, sintered density was 7.26 g•cm-3, hardness was 97 HRB, tensile strength was 515 MPa and elongation was 3.8%.

Structure and Connectivity in an Amorphous Silicon Oxycarbide Polymer-Derived Ceramic: Results from 2D 29Si NMR Spectroscopy

2021 ◽  
Author(s):  
Ivan Hung ◽  
Emanuel Ionescu ◽  
Jishnu Sen ◽  
Zhehong Gan ◽  
Sabyasachi Sen
Keyword(s):  
Nmr Spectroscopy ◽  
Amorphous Silicon ◽  
Silicon Oxycarbide ◽  
29Si Nmr ◽  
Polymer Derived Ceramic ◽  
29Si Nmr Spectroscopy

Does Io have an ammonia atmosphere?

Icarus ◽  
1973 ◽  
Vol 20 (3) ◽  
pp. 284-296 ◽  
Author(s):  
W Sinton
Keyword(s):  
Ammonia Atmosphere

Activation of percolation network in structural-strengthened polymer-derived ceramic for minor deformation detection

Carbon ◽  
2021 ◽  
Author(s):  
Mingyang Lu ◽  
Hui Mei ◽  
Shixiang Zhou ◽  
Tong Zhao ◽  
Laifei Cheng ◽  
...  
Keyword(s):  
Polymer Derived Ceramic ◽  
Percolation Network

Friction and Wear Behavior of Silicon Carbonitride Processed From the Polymer-Derived Ceramic Route

2005 ◽  
Author(s):  
Tsali Cross ◽  
Somuri Prasad ◽  
Rishi Raj
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Silicon Carbonitride ◽  
Linear Wear ◽  
Polymer Derived Ceramic ◽  
Organometallic Precursors ◽  
Future Work ◽  
Contact Pressures

Polymer derived ceramics (PDC’s) are processed from liquid organometallic precursors by cross-linking the polymers into infusible solids, followed by controlled pyrolysis. No previous work regarding their tribology has been reported. Further, the synthesis of PDC’s as thin films, and the role that the nanostructure plays on the mechanical properties has not been reported. The objective of this research was to evaluate the fundamental tribological behavior of polymer derived SiCN in both bulk and thin film form. Friction and wear evaluations were made on bulk materials and thin films using a Si3N4 ballon-disk linear wear tester at various contact pressures and in different environments that contained various amounts of humidity. The micro/nanostructure was characterized by FTIR, microRaman, and scanning electron microscopy. Bulk SiCN gave a low friction coefficient and good wear resistance in humid environments but showed significant fracture and gouging in dry environments at higher contact pressures. Although there is ambiguity regarding the tribology of the thin films there seems to be a dependence upon the nitrogen content within the materials derived from the polymeric stage. The future work will focus on optimizing processing conditions of thin films and investigating the role that nitrogen plays in both bulk and thin film SiCN materials.

Fabrication and electrical properties of polymer-derived ceramic (PDC) thin films for high-temperature heat flux sensors

2011 ◽  
Vol 165 (2) ◽  
pp. 250-255 ◽  
Author(s):  
Duckbong Seo ◽  
Sunghoon Jung ◽  
Stephen J. Lombardo ◽  
Z.C. Feng ◽  
J.K. Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Flux ◽  
High Temperature ◽  
Electrical Properties ◽  
Heat Flux Sensors ◽  
Polymer Derived Ceramic ◽  
Temperature Heat

Polymer-Derived Ceramic Coil Springs

2015 ◽  
Vol 18 (1) ◽  
pp. 70-75
Author(s):  
Sofia Loginkin ◽  
Lorenz Schlier ◽  
Joseph Harris ◽  
Nahum Travitzky ◽  
Peter Greil
Keyword(s):  
Polymer Derived Ceramic

Recent Developments in Polymer‐Derived Ceramic Fibers (PDCFs): Preparation, Properties and Applications – A Review

2007 ◽  
Vol 4 (2-4) ◽  
pp. 249-286 ◽  
Author(s):  
P. Miele† ◽  
S. Bernard ◽  
D. Cornu ◽  
B. Toury
Keyword(s):  
Ceramic Fibers ◽  
Polymer Derived Ceramic ◽  
Recent Developments
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