scholarly journals Mechanical Properties of Fibre Reinforced Geopolymer Composites Exposed to Operating Fluids

2018 ◽  
Vol 278 ◽  
pp. 82-88
Author(s):  
Robin Hron ◽  
Martin Kadlec ◽  
František Martaus

Geopolymers are amorphous aluminosilicate materials which combine low temperature, polymer-like processing with high temperature stability and fire resistibility without toxic smoke generation. For larger expansion of geopolymer composites in aircraft industry, it is necessary to know how it behaves in contact with operating fluids. The specimens were divided into groups exposed to fuel, hydraulic oil, jet oil, and salt mist. Hot/Wet condition until saturation was also applied for one group. Mechanical testing was performed by means of tension, compression, in-plane shear, flexion and interlaminar shear on both reference non-treated and exposed specimens. The largest decrease in all measured strength values was caused by the salt mist. As the most significant, in-plane shear strength was decreased by 85 % by this environment. Operating fluids and hot/wet conditions decreased the shear strength approx. by 15 %. Geopolymer composites are an interesting alternative to existing polymeric and ceramic matrix materials and offers high potential for cost-efficient applications dealing with temperatures up to 1 200°C.

2021 ◽  
Vol 237 ◽  
pp. 01017
Author(s):  
Hang Yang ◽  
Mei-Chun Zhu ◽  
Cong-Qi Fang

Geopolymer composites have been widely researched during recent years as an alternative to sustainable construction materials, which can minimize CO2 emission for its application of industry by-products. Past researches on geopolymer show that it has comparable strength and better high temperature stability compared to ordinary Portland cement. In this paper, the high-temperature behavior of geopolymer paste has been discussed through the last data regarding geopolymer, mainly including its bonding performance with steel, stress-strain characteristics, structural analysis of different observation scales and the performance of special geopolymer paste. In summary, some problems that need to be studied in future researches are put forward.


2013 ◽  
Vol 700 ◽  
pp. 175-178
Author(s):  
Guang Pu Hao

According to the different powder oil ratio of asphalt mixture rutting experiment at high temperature, rotary experimenting machine, for different powder oil ratio dynamic shear experiment of asphalt mortar, using the scanning electron microscope observation on the microstructure of asphalt mortar, powder oil ratio on mixture high temperature stability influence. The experiment results show that: powder oil ratio is larger, stronger anti rut ability, and powder oil ratio is affected by the asphalt shear strength to influence high temperature stability of asphalt mixture, and put forward the best powder oil ratio in the range of 0.18~1.2.


2020 ◽  
pp. 152808372096073
Author(s):  
Marwa A Abd El-baky ◽  
Mohamed A Attia

In this study, the effect of different weight percentages (wt. %) of halloysite nanotubes (HNTs) on the mechanical performance of glass laminate aluminum (Al) reinforced epoxy (GLARE) was investigated. GLARE (3/2) laminates with quasi-isotropic lay-up, [Al/[(0°/90°)/(45°/−45°)]s/Al/[(0°/90°)/(45°/−45°)]s/Al] filled with 0, 0.25, 0.5, 1, 2 and 3 wt. % of HNTs were fabricated using hand lay-up followed by compression molding. To explore the effect of HNTs on the mechanical properties, tensile, flexural, in-plane shear, interlaminar shear, bearing and impact tests were conducted. Results demonstrated that the inclusion of 1 wt. % of HNTs into GLARE leads to maximum improvements of 35.67, 8.50, 28.85, 50.47, 50.27, 30.43, 23.73, 72.08, 30.74, and 51.52% in tensile strength, tensile strain, Young's modulus, modulus of toughness, flexural strength, flexural strain, in-plane shear strength, interlaminar shear strength, bearing strength, and impact strength, respectively, compared to pristine GLARE. An enhancement of 38.89% in the flexural modulus was attained by adding 0.5 wt. % of HNTs to GLARE compared to pristine GLARE. The tensile strength, tensile strain, modulus of toughness, flexural strength, flexural modulus, flexural strain, in-plane shear strength, and interlaminar shear strength of GLARE filled with 3 wt. % of HNTs are 0.91, 0.88, 0.91, 0.91, 0.71, 0.83, 0.85, and 0.91 times those of the original GLARE. But Young’s modulus, bearing strength, and impact strength are 1.10, 1.15 and 1.20 times those of the original GLARE. To investigate the fracture mechanism, field emission scanning electron microscope (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX) were used. The microscopic images revealed that adding HNTs lead to the improvement in the interaction between the epoxy matrix and glass fiber, thereby improving the mechanical properties.


2020 ◽  
Vol 22 (2) ◽  
pp. 99
Author(s):  
S. Nechausov ◽  
B. Bulgakov ◽  
D. Kalugin ◽  
A. Babkin ◽  
A. Kepman ◽  
...  

Composites consisting of propargyl- and allyl/propargyl- modified novolac resins and carbon fabric were obtained by the vacuum infusion molding process. It was established that the presence of potassium cations remaining after the synthesis increase the resin melt viscosity, and acid washing is needed to obtain resins suitable for cost-effective injection techniques of composite fabrication. The mechanical properties of all composites such as compressive strength, tensile strength, in plane shear strength, and interlaminar shear strength were determined at 25, 200 and 230 °С. The carbon fiber reinforced plastics (CFRPs) retained their mechanical properties at temperatures up to 200 °C. It was shown that the use of the obtained allyl-containing polymer matrices improved mechanical properties and increased the thermal stability of the CFRPs in comparison with the propargylated novolac matrices. The composite material with novolac matrices modified by 18% propargyl and 23% allyl groups retains only up to 70% of the initial interlaminar shear strength values at 230 °C which corresponds to the data of the dynamic mechanical analysis of neat cured resins.


2012 ◽  
Vol 204-208 ◽  
pp. 1669-1672
Author(s):  
Yu Zhang ◽  
Bing Han ◽  
Bo Wei Sun

This paper studied on the different chosen-unit-weight shear resistant property on different temperature with direct shear test. The results show that the shear strength on 60°C and the dyna mic stability in rutting test on 60°C have familiar trend, the shear strength and the dynamic stability in rutting test have a good relationship on evaluating the high temperature stability of the asphalt mixture. Based on the performance demand ,this paper gives reasonable Bailey parameters Chosen-unit-weight range.


2019 ◽  
Vol 31 (4) ◽  
pp. 193-202 ◽  
Author(s):  
Qiaoran Zhang ◽  
Abdelhafid Zehri ◽  
Jiawen Liu ◽  
Wei Ke ◽  
Shirong Huang ◽  
...  

Purpose This study aims to develop a bimodal nano-silver paste with improved mechanical property and reliability. Silicon carbide (SiC) particles coated with Ag were introduced in nano-silver paste to improve bonding strength between SiC and Ag particles and enhance high-temperature stability of bimodal nano-silver paste. The effect of sintering parameters such as sintering temperature, sintering time and the proportion of SiC particles on mechanical property and reliability of sintered bimodal nano-silver structure were investigated. Design/methodology/approach Sandwich structures consist of dummy chips and copper substrates with nickel and silver coating bonded by nano-silver paste were designed for shear testing. Shear strength testing was conducted to study the influence of SiC particles proportions on the mechanical property of sintered nano-silver joints. The reliability of the bimodal nano-silver paste was evaluated experimentally by means of shear test for samples subjected to thermal aging test at 150°C and humidity and temperature testing at 85°C and 85 per cent RH, respectively. Findings Shear strength was enhanced obviously with the increase of sintering temperature and sintering time. The maximum shear strength was achieved for nano-silver paste sintered at 260°C for 10 min. There was a negative correlation between the proportion of SiC particles and shear strength. After thermal aging testing and humidity and temperature testing for 240 h, the shear strength decreased a little. High-temperature stability and high-hydrothermal stability were improved by the addition of SiC particles. Originality/value Submicron-scale SiC particles coated with Ag were used as alternative materials to replace part of nano-silver particles to prepare bimodal nano-silver paste due to its high thermal conductivity and excellent mechanical property.


Alloy Digest ◽  
1989 ◽  
Vol 38 (1) ◽  

Abstract UNS NO6455 is a nickel-chromium-molybdenum alloy with outstanding high-temperature stability as shown by high ductility and corrosion resistance even after long-time aging in the range 1200-1900 F. The alloy also has excellent resistance to stress-corrosion cracking and to oxidizing atmospheres up to 1900 F. 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: Ni-367. Producer or source: Nickel and nickel alloy producers.


Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  

Abstract UNS No. R54620 is an alpha-beta titanium alloy. It has an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high strength is required. It has outstanding advantages for long-time use at temperatures to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-86. Producer or source: Titanium alloy mills.


The temperature factor is one of the limiting factors for obtaining high yields of crops, so one of the main tasks of selection is to search for temperature-resistant genotypes and to create on their basis the banks of crops with high temperature stability. The first step to solving this problem is to conduct a rapid assessment of the temperature plasticity of large populations and to isolate breeding-valuable genotypes from them. There are numerous methods that allow, in the short term with minimal technical and material costs, to carry out an initial assessment of a large number of genotypes at sporophytic level and differentiate them by resistance to the temperature factor. These methods include the method of estimating pollen populations. These studies have repeatedly been conducted on many cultures, their correctness is due to the expression of a large part of the plant genome, both at the diploid and haploid levels of development and demonstrated by many studies in this direction. The aim of our study was to study the stability of gametophyte and sporophyte of collecting varieties and varieties of winter rape to elevated temperatures, to study the correlation between the heat resistance of sporophyte and gametophyte.


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