scholarly journals Prepregs for Temperature Resistant Composites

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4012 ◽  
Author(s):  
Eliška Haincová ◽  
Pavlína Hájková ◽  
Jan Kohout
Keyword(s):  
Tensile Properties ◽  
Preparation Method ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Matrix Composites ◽  
Heat Treated ◽  
Fabric Composites ◽  
Original Strength ◽  
Alkali Activated ◽  
Inorganic Matrix

In this paper, carbon fabric reinforced inorganic matrix composites were prepared. The inorganic matrix based on alkali activated aluminosilicate was used because of its resistance to fire and the temperatures up to 1000 °C. Influence of heat treatment of fabric, high temperature treatment of composite and preparation method on the mechanical properties and morphology of the composites were studied. The preparation of composites with the subsequent steps of impregnation, layering and curing of the composites was compared with the prepreg preparation method, which separates the impregnation of the reinforcement from the production of the composite. The SEM photographs show no differences in morphology between composites prepared from heat treated fabric and composites prepared from original fabrics. All four series of samples were comparatively saturated with matrix. Despite this, tensile properties of heat-treated fabric composites were negatively affected. While composites with heat-treated fabric reached the tensile strength up to 274 MPa, composites prepared without heat-treated fabric exhibited strengths higher than 336 MPa. Samples exposed to temperatures reaching 600 °C retained up to 40% of their original strength. The effect of composite preparation method on the tensile properties of the composites has not been proved.

Quality Improvement of CNT by Thermal Treatment and Enhancement of Properties of CNT/Polymer Composites

2018 ◽  
Vol 772 ◽  
pp. 23-27
Author(s):  
Takashi Amemiya ◽  
Toshiyuki Yasuhara
Keyword(s):  
Polymer Composites ◽  
Mechanical Characteristics ◽  
Polymer Matrix Composites ◽  
Lower Surface ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Matrix Composites ◽  
High Quality ◽  
Heat Treated ◽  
Double Wall

Since CNTs (carbon nanotubes) have excellent electrical and mechanical characteristics, their application as fillers for polymer matrix composites is expected to have great potential. The purpose of this study is to clarify the effect of CNT’s crystallinity quality, which is given by high temperature treatment (i.e. annealing), on the properties of CNT/polymer composites. In this study, double wall type CNT (DWNT) and multi wall type CNT (MWNT) were used and heat treated at up to 2000°C to achieve highly improved crystallinity. Electrical and mechanical properties of the CNT/polymer composites were compared with the various CNT’s crystallinity qualities as measured by ID/IG ratios. As a result, although the composites with higher quality CNTs showed considerably lower surface resistivities, however the same composites had lower Young's modulus and tensile strengths. The reason is thought to be that the high quality CNT has low surface activity and weak adhesion between the polymer and the CNT surface. This suggests that CNTs with higher quality do not always contribute to the improvement to the properties of CNT/polymer composites.

scholarly journals Experimental Study on Mechanical Property and Pore Distribution of Limestone Specimens after Heat Treatment under Different Heating Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yujie Feng ◽  
Haijian Su ◽  
Qian Yin ◽  
Liyuan Yu ◽  
Yingchao Wang
Keyword(s):  
Thermal Decomposition ◽  
Temperature Treatment ◽  
Pore Distribution ◽  
Rock Properties ◽  
High Temperature Treatment ◽  
Heating Process ◽  
Heating Condition ◽  
Heat Treated ◽  
Significant Temperature ◽  
Mechanical Performances

The thermal effect of rocks not only depends on the temperature level but also may be influenced by the factors including heating environment, heating rate, and cooling method. In this study, approximate vacuum (V) and air circulation (A) heating condition are, respectively, applied on the limestone specimens in the whole heating process. Then, physical, mechanical, and nuclear magnetic resonance (NMR) tests were carried out to investigate the effect of heating conditions on the rock properties. The results show that heating conditions have significant effects on mechanical properties of limestone specimens (including peak strength, elasticity modulus, secant modulus, and crack initiation stress), which are due to the interference effect on the oxidation and thermal decomposition. It is worth noting that the significant temperature range of the heating condition is 450 ∼ 750°C, during which the mechanical performances of heat-treated specimens under V condition obviously outperform those under A condition. Combining the NMR results and the microstructure images from scanning electron microscope (SEM) technology, the evolution of pore distribution was revealed. As temperature increases from room temperature to 900°C, porosity increases gradually. However, pore distribution changes from small and medium pores dominating to large pore dominating and then to medium pore dominating. For limestone specimens after high-temperature treatment above 450°C, mineral crystals may melt and reconsolidate, filling in some of the previously large pores generated by thermal decomposition.

Research of Behaviour of Inorganic Matrix Composites Exposed to Extreme Temperatures

2015 ◽  
Vol 1124 ◽  
pp. 117-122
Author(s):  
Amos Dufka ◽  
Tomáš Melichar
Keyword(s):  
High Risk ◽  
High Temperatures ◽  
Temperature Effects ◽  
Complex Analysis ◽  
Matrix Composites ◽  
Mechanical Parameters ◽  
Extreme Temperatures ◽  
Alkali Activated ◽  
Inorganic Matrix

The article is focused on complex analysis of the principles of degradation of composites based on alkali-activated materials exposed to extreme temperatures (max. temperature 1200 degree of Celsius). Thanks to specific properties these materials show a remarkable potential for the special application, for example for construction with high risk of fire etc. The effect of high temperatures shall be tested not only at such extreme levels but also at gradually increasing temperatures. The temperature effects shall be evaluated not only in of changes physic-mechanical parameters but also the physic-chemical determinations.

scholarly journals Spectroscopic Identification of Amber Imitations: Different Pressure and Temperature Treatments of Copal Resins

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1223
Author(s):  
Ting Zheng ◽  
Haibo Li ◽  
Taijin Lu ◽  
Xiaoming Chen ◽  
Bowen Li ◽  
...  
Keyword(s):  
Spectral Characteristics ◽  
Experimental Methods ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Resonance Spectroscopy ◽  
Spectroscopic Methods ◽  
Spectral Changes ◽  
Multi Stage ◽  
Heat Treated ◽  
Spectroscopic Identification

Copal resins can be treated with heat and/or pressure to imitate ambers in the gem market. To explore the effects of different modification conditions on post-treatment spectral changes, five experimental methods with different temperature–pressure parameters were designed to modify two types of copal resins. The treated copal resins were examined by infrared, Raman and nuclear magnetic resonance spectroscopy. Results indicate that all the treatment methods simulate the maturation process, with spectral characteristics becoming more similar to those of ambers. Multi-stage heat–pressure treatment has the most significant effect on Colombia and Madagascar copal resins, with their spectra being similar to those of Dominican and Mexican ambers. Rapid high-temperature treatment at 180 °C modified the Borneo copal resin, with its infrared spectrum developing a “Baltic shoulder” resembling that of heat-treated Baltic amber. Even though there are many similarities between treated copal resins and natural ambers, they can still be distinguished by spectroscopic methods.

scholarly journals Effect of high temperature treatment of Vicia faba roots on the oxidative stress enzymes in leaves.

1997 ◽  
Vol 44 (2) ◽  
pp. 315-321 ◽  
Author(s):  
M Filek ◽  
R Baczek ◽  
E Niewiadomska ◽  
M Pilipowicz ◽  
J Kościelniak
Keyword(s):  
Oxidative Stress ◽  
Vicia Faba ◽  
Temperature Treatment ◽  
Activity Analysis ◽  
High Temperature Treatment ◽  
Sod Activity ◽  
Heat Treated ◽  
Oxidative Stress Enzymes ◽  
Stress Enzymes ◽  
Cell Fractions

The following types of superoxide dismutase (SOD) have been found in the leaves of Vicia faba: one isoenzyme of Mn-SOD and four isoenzymes of Cu/Zn-SOD. The treatments of roots with boiling water caused an increase of SOD activity in the leaves. The highest increase was measured after 5 s of the treatment. It was accompanied by a significant increase in catalase activity. Analysis of cell fractions' revealed an increase of SOD activity in the plastids and mitochondria isolated from the leaves of those plants whose roots were heat-treated. However, there was no distinct change of SOD activity in the cytosolic fraction. The possibility of an electric wave intervention inducing oxidative stress in the leaves is discussed.

Effect of High Temperature Treatment in Ar Atmosphere on the Tensile Strength and Structure of SiC Fiber

2021 ◽  
Vol 871 ◽  
pp. 159-164
Author(s):  
Jin Juan Fan ◽  
Qiang Qiang Zhu ◽  
Zhe Qi ◽  
Jin Fa Ye
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Matrix Composites ◽  
Service Temperature ◽  
Sic Fiber ◽  
Structure Changes

The properties and structure changes of SiC fiber in high temperature determine the service temperature of the reinforced ceramic matrix composites, so the properties of SiC fibers under high temperature are very important. The SiC-A and SiC-B fibers were treated at 1200, 1350 and 1600°C in Ar atmosphere. Then the tensile strength was measured, the microstructure and composition of the fibers were analyzed by SEM, EDS, XRD and AES. The results show that the tensile strength of SiC-A and SiC-B decrease slowly at 1200 and 1350°C, but decrease rapidly at 1600°C.

UNS A02080

Alloy Digest ◽  
1988 ◽  
Vol 37 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
General Purpose ◽  
Sand Casting ◽  
Casting Alloy ◽  
Heat Treated

Abstract UNS No. A02080 is a heat-treatable casting alloy characterized by good castability, machinability and resistance to corrosion. It is produced by sand casting and is a general-purpose alloy recommended in both the as-cast and heat-treated conditions. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-286. Producer or source: Various aluminum companies.

BRUSHFORM 96

Alloy Digest ◽  
2014 ◽  
Vol 63 (7) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
High Performance ◽  
Strength Characteristics ◽  
Bend Strength ◽  
Copper Nickel ◽  
Heat Treated

Abstract BrushForm 96 strip is a high-performance, heat treatable spinodal copper-nickel-tin alloy designed to provide optimal formability and strength characteristics in conductive spring applications. It is available in both pre-heat treated (mill hardened) and heat treatable (age hardenable) forms. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. and bend strength. It also includes information on forming. Filing Code: Cu-833. Producer or source: Materion Brush Performance Alloys.

BRUSH ALLOY 190

Alloy Digest ◽  
1968 ◽  
Vol 17 (12) ◽  
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Heat Treating ◽  
Copper Strip ◽  
Beryllium Copper ◽  
Heat Treated

Abstract Brush Alloy 190 is a mill-heat treated beryllium copper strip with a tensile strength up to 190,000 psi. It eliminates the need of customer heat-treating by providing high properties combined with exceptional formability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: Cu-194. Producer or source: Brush Beryllium Company.

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