scholarly journals High-Performance SiC-Polycrystalline Fiber with Smooth Surface

Ceramics ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 165-174
Author(s):  
Ryutaro Usukawa ◽  
Toshihiro Ishikawa
Keyword(s):  
Oxygen Content ◽  
High Performance ◽  
Smooth Surface ◽  
High Strength ◽  
Degradation Reactions ◽  
Production Processes ◽  
Different Types ◽  
Degradation Reaction ◽  
The Relationship ◽  
Production Conditions

Polymer-derived SiC-polycrystalline fibers show excellent heat-resistance up to 2000 °C, and relatively high strength. Up to now, through our research, the relationship between the strength and residual defects of the fiber, which were formed during the production processes (degradation and sintering), has been clarified. In this paper, we addressed the relationship between the production conditions and the surface smoothness of the obtained SiC-polycrystalline fiber, using three different raw fibers (Elementary ratio: Si1Al0.01C1.5O0.4~0.5) and three different types of reactors. With increase in the oxygen content in the raw fiber, the degradation during the production process easily proceeded. In this case, the degradation reactions (SiO + 2C = SiC + CO and SiO2 + 3C = SiC + 2CO) in the inside of each filament become faster, and then the CO partial pressure on the surface of each filament was considered to be increased. As a result, according to Le Chatelier’s principle, the surface degradation reaction and grain growth of formed SiC crystals would be considered to become slower. That is to say, using the raw fiber with higher oxygen content and closed system (highest CO content in the reactor), a much smoother surface of the SiC-polycrystalline fiber could be achieved. Furthermore, the similar effect obtained by simple oxidation of the SiC-polycrystalline fiber was confirmed, and the advantageous points of the aforementioned process were also considered.

scholarly journals High-Performance SiC-Polycrystalline Fiber with Smooth Surface

2018 ◽  
Author(s):  
Ryutaro Usukawa ◽  
Toshihiro Ishikawa
Keyword(s):  
Oxygen Content ◽  
Open System ◽  
Closed System ◽  
High Performance ◽  
Production Condition ◽  
High Strength ◽  
Degradation Reactions ◽  
Different Types ◽  
Degradation Reaction ◽  
The Relationship

Polymer-derived SiC-polycrystalline fiber (Tyranno SA) shows excellent heat-resistance up to 2000oC, and relatively high strength. Up to now, through our research, the relationship between the strength and residual defects of the fiber, which were formed during the production processes (degradation and sintering), has been clarified. In this paper, we addressed the relationship between the production condition and the surface roughness of the obtained SiC-polycrystalline fiber, using three different raw fibers (Elementary ratio: Si1Al0.01C1.5O0.4~0.5) and three different types of reactor (Open system, Partially-open system, and Closed system). With increase in the oxygen content in the raw fiber, the degradation during the production process easily proceeded. In this case, the degradation reactions (SiO+2C=SiC+CO and SiO2+3C=SiC+2CO) in the inside of each filament become faster, and then the CO partial pressure on the surface of each filament is considered to be increased. In consequence, according to Le Chatelier’s principle, the surface degradation reaction and grain growth of formed SiC crystals would be considered to become slower. That is to say, using the raw fiber with higher oxygen content and closed system (highest CO content in the reactor), much smoother surface of the SiC-polycrystalline fiber could be achieved.

Preventive Effects of Fibers on Spalling of UFC at High Temperatures

2014 ◽  
Vol 5 (3) ◽  
pp. 229-238 ◽  
Author(s):  
Mitsuo Ozawa ◽  
Zhou Bo ◽  
Yuichi Uchida ◽  
Hiroaki Morimoto
Keyword(s):  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Short Fibers ◽  
Severe Damage ◽  
Explosive Spalling ◽  
Jute Fibers ◽  
Different Types ◽  
High Strength Fiber ◽  
The Relationship ◽  
Preventive Effects

This paper investigates the relationship between spalling behavior and weight loss for ultra-high-strength fiber-reinforced concrete (UFC) containing different types short fibers (jute, PP, WSPVA) in high-temperature environments at 400, 600 and 800 °C. The explosive spalling that occurred under these conditions caused severe damage to the control specimen but only slight damage to the specimen with jute fiber. It was therefore inferred that adding 0.19% by volume of natural jute fibers (length: 12 mm) to UFC is effective in the prevention of spalling-related damage.

The Mix Design Method and Performance for C60 Concrete Poles with High Strength, Impermeability and Frost Resistance

2014 ◽  
Vol 1035 ◽  
pp. 161-165
Author(s):  
Hai Jun Xing ◽  
Xin Tuo Hou ◽  
Bin Rong Zhu ◽  
Zi Fu Zhang ◽  
Zhen Fu Li
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Design Method ◽  
High Strength ◽  
Mix Design ◽  
Mineral Admixtures ◽  
Concrete Mix ◽  
And Performance ◽  
The Impact ◽  
The Relationship

In corrosive soils areasand extremely cold regions,high performance is required inthe impermeability and frost resistanceof concrete poles. In this paper, the mix design of C60 high performance concrete and the relationship between mix parameters and performance is studied and analyzed ,and the influence of the water-cement ratio, the amount of cementation materials, the mineral admixtures and other factors on High Performance Concrete is discussed, as well as the impact of different admixtures for concrete. According to the analysis results, the concrete mix is designed and used in practice.

Effect of Modified Phosphogypsum on the Mechanical Properties of Super Sulphate Cement

2012 ◽  
Vol 161 ◽  
pp. 264-268 ◽  
Author(s):  
Yu Xin Gao ◽  
Bao Ying Yu ◽  
Fen Lian Xu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Chemical Composition ◽  
High Performance ◽  
High Strength ◽  
Strengthening Mechanisms ◽  
Particle Size Analyzer ◽  
Composition Analyzer ◽  
The Relationship

The effect of phosphogypsum (PG) modified on mechanical properties of super sulphate cement (SSC) was systematically studied in this paper. Then attentions and researches were focused on the relationship between specific surface (SSA) and the mechanical properties of SSC containing PG modified by calcining, floating, neutralizing with alkali. Strengthening mechanisms of SSC were further investigated and analyzed by laser particle size analyzer and chemical composition analyzer at last. Results showed that the high strength SSC with the compressive strength 35MPa at 7 days, over 60MPa at 28 days, and some even more than 70MPa at 56 days, could be successfully developed. This research can provide a key reference for the utilization of PG and development of high performance eco-SSC.

Adaptive Feedrate Scheduling and Material Engagement Analysis for High Performance Machining

Manufacturing ◽  
2002 ◽  
Author(s):  
Jirawan Kloypayan ◽  
Yuan-Shin Lee
Keyword(s):  
Material Removal ◽  
High Performance ◽  
Tool Path ◽  
Tool Path Generation ◽  
Feedrate Scheduling ◽  
Different Types ◽  
Cad Cam ◽  
Tool Motion ◽  
The Relationship ◽  
Cam Systems

This paper presents a technique of feedrate scheduling by analyzing the material removal volume when a tool moves in linear, circular, or parametric curved motions. Tool motions of different types of endmilling cutters are considered in this study. By studying the relationship between the cutter geometry and the tool motion, the material removal rates of different cutters are analyzed. The adaptive feedrate scheduling can be determined to maintain a constant cutting load. The technique developed in this research can be used for tool path generation in CAD/CAM systems for 2.5D NC machining.

scholarly journals Ultrafine and High-Strength Silk Fibers Secreted by Bimolter Silkworms

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2537 ◽  
Author(s):  
Kaiyu Guo ◽  
Xiaolu Zhang ◽  
Zhaoming Dong ◽  
Yuhui Ni ◽  
Yuqing Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Strength ◽  
Silk Gland ◽  
X Ray Diffraction ◽  
Ultrafine Fibers ◽  
Silk Fibers ◽  
Warmth Retention ◽  
The Relationship ◽  
Β Sheet

Ultrafine fibers are widely employed because of their lightness, softness, and warmth retention. Although silkworm silk is one of the most applied natural silks, it is coarse and difficult to transform into ultrafine fibers. Thus, to obtain ultrafine high-performance silk fibers, we employed anti-juvenile hormones in this study to induce bimolter silkworms. We found that the bimolter cocoons were composed of densely packed thin fibers and small apertures, wherein the silk diameter was 54.9% less than that of trimolter silk. Further analysis revealed that the bimolter silk was cleaner and lighter than the control silk. In addition, it was stronger (739 MPa versus 497 MPa) and more stiffness (i.e., a higher Young’s modulus) than the trimolter silk. FTIR and X-ray diffraction results revealed that the excellent mechanical properties of bimolter silk can be attributed to the higher β-sheet content and crystallinity. Chitin staining of the anterior silk gland suggested that the lumen is narrower in bimolters, which may lead to the formation of greater numbers of β-sheet structures in the silk. Therefore, this study reveals the relationship between the structures and mechanical properties of bimolter silk and provides a valuable reference for producing high-strength and ultrafine silk fibers.

BERYLCO 25

Alloy Digest ◽  
1973 ◽  
Vol 22 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
High Performance ◽  
High Strength ◽  
Heat Treating ◽  
Beryllium Copper

Abstract BERYLCO 25 is the standard high-performance beryllium copper alloy most widely used because of its high strength, hardness and excellent spring characteristics. BERYLCO 25 is the updated version of BERYLCO 25S (Alloy Digest Cu-3, November 1952). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-271. Producer or source: Kawecki Berylco Industries Inc..

ARMCO PH 13-8Mo

Alloy Digest ◽  
1990 ◽  
Vol 39 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
High Performance ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance

Abstract ARMCO PH 13-8Mo is designed for high-performance applications requiring high strength coupled with excellent resistance to corrosion and stress corrosion. It has excellent toughness, good transverse properties and excellent forgeability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-224. Producer or source: Baltimore Specialty Steels Corporation. Originally published May 1969, revised February 1990.

STRENX 100

Alloy Digest ◽  
2019 ◽  
Vol 68 (2) ◽  
Keyword(s):  
Yield Strength ◽  
Physical Properties ◽  
Structural Steel ◽  
Tensile Properties ◽  
High Performance ◽  
High Strength ◽  
Minimum Yield

Abstract Strenx 100 is a high-strength, high-performance structural steel with a minimum yield strength of 690 MPa (100 ksi). It meets the requirements of ASTM A514 Grade S. Strenx 100 is a US Customary steel similar to Strenx 700 (Alloy Digest SA-779, February 2017). This datasheet provides information on composition, physical properties, and tensile properties. Filing Code: SA-838. Producer or source: SSAB Swedish Steel Inc..

OUTOKUMPU TYPE 630

Alloy Digest ◽  
2016 ◽  
Vol 65 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
High Performance ◽  
High Strength ◽  
Heat Treating ◽  
304 Stainless Steel ◽  
Type 304 ◽  
Type 304 Stainless Steel

Abstract Outokumpu Type 630 is a martensitic age hardenable alloy of composition 17Cr-4Ni. The alloy has high strength and corrosion resistance similar to that of Type 304 stainless steel. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-1238. Producer or source: Outokumpu High Performance Stainless.

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