Influence of Carbon Cloth Filaments Upon the Properties of 2D C/SiC via Precursor Infiltration and Pyrolysis Process

2008 ◽  
Vol 368-372 ◽  
pp. 1041-1043 ◽  
Author(s):  
Feng Zhang ◽  
Hai Feng Hu ◽  
Qi Kun Wang ◽  
Yu Di Zhang ◽  
Chang Rui Zhang
Keyword(s):  
Fracture Toughness ◽  
Fracture Surface ◽  
Flexural Strength ◽  
Volume Ratio ◽  
Carbon Cloth ◽  
Pyrolysis Process ◽  
Fiber Volume ◽  
Sic Composites

In this paper, 2D C/SiC composites with different carbon cloth filaments (1K, 3K) were prepared via precursor infiltration and pyrolysis (PIP) process. The flexural strength of 2D-1K C/SiC composites was 380MPa, and fracture toughness was 16.8MPa-m1/2, while those of 2D-3K C/SiC were 305MPa and 14.4MPa-m1/2, respectively. The differences of these two composites were analyzed from fiber volume ratio in the composites, density, and fracture surface (SEM) of the samples.

Preparation of BN Coating on KD-II Silicon Carbide Fiber by Dip-Coating Process

2015 ◽  
Vol 816 ◽  
pp. 186-191 ◽  
Author(s):  
Bei Yang ◽  
Xin Gui Zhou ◽  
Jin Shan Yu ◽  
Hong Lei Wang
Keyword(s):  
Crystal Structure ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
Flexural Strength ◽  
Dip Coating ◽  
Strength Test ◽  
Coating Process ◽  
Silicon Carbide Fiber ◽  
Pyrolysis Process ◽  
Sic Composites

Boron nitride (BN) coating on KD-II silicon carbide fiber was prepared from boric acid and urea by a 4-circle dip-coating process. SiCf/SiC composites were prepared from the precursor LPVCS by a HP(heat pressure) assisted PIP(precursor infiltration and pyrolysis) process. The microstructure and crystal structure of the coatings were characterized by SEM and XRD. XPS was adapted to analysis the composition and contents of different elements on the surface of BN coating. The influence of dip-coating process to the fibers was studied by the monofilament strength test. As the results, the monofilament strengths of the dip-coated fibers decreased firstly and increased subsequently. The strengths were slightly higher (3.4%) than the original fiber after 4 circles. The average flexural strength and fracture toughness of the composites with BN coating are respectively 290.8 MPa and 12.09 MPa⋅m1/2, while those of composites without coating are 144.1 MPa and 6.72 MPa⋅m1/2, respectively.

Online-Joining of C/SiC-C/SiC via Slurry Reaction and Precursor Infiltration and Pyrolysis Process with C/SiC Pins

2012 ◽  
Vol 531-532 ◽  
pp. 135-140 ◽  
Author(s):  
Yu Di Zhang ◽  
Hai Feng Hu ◽  
Chang Rui Zhang ◽  
Guang De Li
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Fracture Mode ◽  
Pyrolysis Process ◽  
Strong Bond ◽  
Sic Composites ◽  
Maximum Shear Strength ◽  
Application Prospects ◽  
Complex Components

C/SiC composites have widely application prospects in the field of aeronautic and aerospace for their excellent properties. The joining of C/SiC composites is a key to fabricate large and complex components. In this paper, 1D C/SiC pins were prepared by precursor infiltration and pyrolysis (PIP) process and used to join C/SiC composites by Slurry react (SR) and PIP process. The shear strength of the C/SiC pins with different carbon fiber volumes was investigated with the maximum shear strength as high as 339.46MPa. Influences of C/SiC pins on the joining properties of C/SiC composites were studied. The shear strength and flexural strength of C/SiC-C/SiC joining are improved from 9.17MPa and 30.41MPa without pins to 20.06MPa and 75.03MPa with one C/SiC pin (diameter 2mm), respectively. The reliability of C/SiC-C/SiC joining is also improved with C/SiC pins in that the fracture mode changes from catastrophic without pins to non-catastrophic. The SEM photos show a strong bond between joining layer and C/SiC composites without obvious interface.

Experimental Study on Flexural and Fatigue Property of Steel Fiber Reinforced Prestressed Concrete Slab

2012 ◽  
Vol 166-169 ◽  
pp. 1083-1086
Author(s):  
Shi Yue Wang ◽  
Jie Hou ◽  
Bi Huang
Keyword(s):  
Flexural Strength ◽  
Plastic Strain ◽  
Strain Amplitude ◽  
Prestressed Concrete ◽  
Strain Energy ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Volume Ratio ◽  
Fiber Volume ◽  
Plastic Strain Energy

The flexural strength of steel fiber reinforced prestressed concrete slab (SFRPCS) with different steel fiber volume ratio (0%, 1%, 2%) is obtained according to four-point bend test, which reveals that the addition of steel fiber can retard the crack growth and enhance the flexural strength of SFRPCS. With the results of fatigue experiment, the damage forms of SFRPCS is analyzed, strain amplitude-cycle ratio curves are obtained and the plastic strain energy of SFRPCS with different steel fiber volume ratio during fatigue process is calculated. It is shown that after 80% fatigue life, the more of the steel fiber volume ratio, the less of the strain amplitude increment, which proves the addition of steel fiber can prevent the concrete matrix from cracking and improve the fatigue performance of SFRPCS, and the plastic strain energy curve of SFRPCS shows obviously three- stage development.

Potential External Strengthening of Reinforced Concrete Beam Using Natural Fiber Composite Plate

2018 ◽  
Vol 878 ◽  
pp. 41-48 ◽  
Author(s):  
Siew Choo Chin ◽  
Foo Sheng Tong ◽  
Shu Ing Doh ◽  
Jolius Gimbun ◽  
Yuen Kei Foo ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Volume Ratio ◽  
Physical And Mechanical Properties ◽  
Composite Plates ◽  
Reinforced Concrete Beam ◽  
Fiber Volume ◽  
External Strengthening

A study has been conducted to investigate the potential use of mengkuang leaves or Pandanus atrocarpus bonded with epoxy resin as external strengthening material for the strengthening of reinforced concrete (RC) beams. Physical and mechanical properties as well as structural properties of the mengkuang leaves-epoxy composite plates (MLECP) were evaluated in this study. Chemical treatment was performed on the dried mengkuang leaves using sodium hydroxide (NaOH) with concentrations of 2%, 5% and 8%. Scanning electron microscope (SEM) and flexural strength tests were conducted on the mengkuang leaves and flexural specimens, respectively. All the beams were tested to failure under four-point loading. Results showed that the flexural strength of the composite with 0.3 fiber volume ratio exhibited the highest flexural strength. Strengthening of RC beam using MLECP managed to increase the beam capacity.

Effect of Processing Condition on the Microstructure and Mechanical Properties of Ti3SiC2/SiC Composites

2010 ◽  
Vol 658 ◽  
pp. 352-355 ◽  
Author(s):  
Hong Feng Yin ◽  
Lin Lin Lu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Processing Condition ◽  
High Porosity ◽  
Pressing Temperature ◽  
Pressing Method ◽  
Microstructure And Mechanical Properties ◽  
Sic Composites

Ti3SiC2/SiC composites were fabricated by reactive hot pressing method. Effect of processing condition on the microstructure and mechanical properties of the composites were investigated. The results showed that: (1) Hot-pressing temperature influenced the phase constituent of Ti3SiC2/SiC composites. The flexural strength and fracture toughness of composites increased with hot pressing temperature. (2) The flexural strength and fracture toughness of composites increased when the content of SiC was increased. When the SiC content was 30wt% the flexural strength and fracture toughness of Ti3SiC2/SiC composite were 371MPa and 6.9MPa•m1/2 respectively. However, when the content of SiC reached 50wt%, the flexural strength and fracture toughness of composites decreased due to high porosity in the composites. (3) The flexural strength and fracture toughness of composites increased with the particle size of SiC added in composites. (4) Ti3SiC2/SiC composites were non-brittle at room temperature.

Mechanical Properties of Modified Polypropylene Coarse Fiber-Reinforced, High-Strength, Lightweight Concrete

2011 ◽  
Vol 374-377 ◽  
pp. 1499-1506
Author(s):  
Rong Hui Zhang ◽  
Jian Li
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
High Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume

In this study, the effect of micro-expansion high strength grouting material (EGM) and Modified polypropylene coarse fiber (M-PP fiber) on the mechanical properties of lightweight concrete are investigated. The influence of EGM and M-PP fiber on compressive strength , flexural strength and drying shrinkage of concrete are researched, and flexural fracture toughness are calculated. Test results show that the effect of EGM and M-PP fiber volume fraction (Vf) on flexural strength and fracture toughness is extremely prominent, compressive strength is only slightly enhanced, and the rate of shrinkage is obviously decreased. It is observed that the shape of the descending branch of load-deflection and the ascending branch of shrinkage-age tends towards gently with the increase of Vf. And M-PP fiber reinforced lightweight aggregate concrete is more economical.

Preparation and Properties of 2D Carbon Cloth Reinforced Ultra-High Temperature Ceramic Matrix Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1050-1052 ◽  
Author(s):  
Yong Lian Zhou ◽  
Hai Feng Hu ◽  
Yu Di Zhang ◽  
Qi Kun Wang ◽  
Chang Rui Zhang
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Carbon Cloth ◽  
Matrix Composites ◽  
Pyrolysis Process ◽  
Sic Composites ◽  
Polymer Infiltration ◽  
Ultra High Temperature

In this paper the preparation of carbon fiber reinforced ultra-high temperature ceramic matrix composites was reported. Polymer infiltration and pyrolysis process was used to prepare 2D C/TaC-SiC, C/NbC-SiC, and C/ZrC-SiC composites. The fracture strengths of all the samples were around 300MPa and toughness around 10MPa-m1/2. Standard oxyacetylene torch tests (>3000°C, 30s) showed that the minimum ablative rate of 2D C/SiC-ZrC was as low as 0.026 mm/s, much smaller than that of 2D C/SiC composites (0.088mm/s).

Preparation and Properties of 2D C/SiC-TaC Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1771-1773 ◽  
Author(s):  
Yu Di Zhang ◽  
Chang Rui Zhang ◽  
Hai Feng Hu ◽  
Yong Lian Zhou
Keyword(s):  
Fracture Toughness ◽  
Mass Loss Rate ◽  
Volume Ratio ◽  
Leading Edge ◽  
Ceramic Matrix Composites ◽  
Tantalum Carbide ◽  
Space Vehicles ◽  
Matrix Composites ◽  
Sic Composites ◽  
Powder Content

Ultra high temperature ceramic matrix composites (UHTCC) are being considered as the most promising materials for leading edge and nose cap of hypersonic spacecrafts, reusable space vehicles and so on. In the paper, 2D carbon fiber cloth reinforced silicon carbide-tantalum carbide (2D SiC-TaC) UHTCC was fabricated by slurry-pasting and precursor infiltration pyrolysis process (PIP). Influences of the volume ratio (10, 20, 30, 60, 80 and 100%) of TaC powder on mechanical properties and ablative resistance of 2D C/SiC-TaC composites were studied. The results showed that the relative density of composites with 60vol% TaC powder was the highest, the flexural strength of the composites reached 356MPa and the mass loss rate and recession rate were 0.0116g/s and 0.026mm/s respectively, while those of C/SiC composites were 0.0166g/s and 0.062mm/s respectively. Moreover, the higher TaC powder content, the smaller the fracture toughness of the composites was. The fracture toughness of the 2D C/SiC-TaC composites with 100vol% TaC powder was only 8.69 MPa-m1/2, while that of C/SiC composites was over 15.0 MPa-m1/2.

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