Results of experimental studies into high-temperature adhesive compositions on bismaleimide base as applied to rocket and space hardware

2020 ◽  
pp. 24-34
Author(s):  
Andrey I ALYAMOVSKIY ◽  
Dmitry Ya. DAVYDOV ◽  
Elena V. ZEMTSOVA ◽  
Nikolay I. KOPYL
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Manufacturing Process ◽  
Fracture Behavior ◽  
Experimental Studies ◽  
Mechanical Tests ◽  
Volatile Content ◽  
Degree Of Cure ◽  
Film Adhesive ◽  
Adhesive Compositions

The paper presents results of comprehensive experimental studies into high-temperature adhesive compositions and foaming paste on bismaleimide base, and characterizes their properties from the standpoint of the manufacturing process (thixotropy, foaming coefficient, volatile content, degree of cure, spreadability and fluidity) and mechanical strength (ultimate strength for shear, uniform tear and compression). The effect of accelerated environmental tests and irradiation on mechanical properties was studied and, and the level of offgassing in vacuum was determined for the adhesive compositions and the the foaming paste. Key words: high-temperature adhesive compositions, film adhesive, thixotropy, foaming coefficient, degree of cure, spreadability, fluidity, mechanical tests, fracture behavior, accelerated climatic tests, irradiation.

New manufacturing process to develop antibacterial dyed polyethylene terephthalate sutures using plasma functionalization and chitosan immobilization

2021 ◽  
pp. 152808372110505
Author(s):  
Nesrine Bhouri ◽  
Faten Debbabi ◽  
Abderrahmen Merghni ◽  
Esther Rohleder ◽  
Boris Mahltig ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Terephthalate ◽  
Manufacturing Process ◽  
Antibacterial Effect ◽  
Inhibition Zone ◽  
The United States ◽  
Mechanical Tests ◽  
Inflammatory Reactions ◽  
Plasma Functionalization

The main purpose of this paper is to develop a new manufacturing process leading to have antibacterial dyed non-absorbable braided polyethylene terephthalate (PET) sutures using biocompatible and non-toxic products. This manufacturing process allows better visibility of sutures in the surgical field and reduces the risk of infections and inflammatory reactions without affecting the mechanical properties while meeting the United States Pharmacopeia (USP) requirements. Plasma functionalization, acrylic acid (AA) grafting, and bioactive chitosan (CH) coating were used before the dyeing process with a biocompatible non-toxic acid dye, approved by the Food and Drug Administration (FDA). The influence of experimental parameters on the suture properties and the K/S values of the dyed sutures are investigated. Infrared spectroscopy confirms the presence of new bonds to immobilize chitosan on the surface of the suture. Mechanical tests confirm that the mechanical properties of sutures have not been affected. The in vitro antibacterial effect of dyed PET sutures showed an inhibition zone of 11 mm against S. aureus, 4 mm against P. aeruginosa, and 1 mm against E. coli. This study reveals that the new finishing process of sutures is a promising method to achieve an antibacterial effect with a uniform shade and smooth surfaces.

Investigation of Impact Compressive Mechanical Properties of Sandstone After as well as Under High Temperature

2014 ◽  
Vol 33 (6) ◽  
pp. 585-591 ◽  
Author(s):  
Shi Liu ◽  
Jinyu Xu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Critical Temperature ◽  
High Temperatures ◽  
Experimental Studies ◽  
Practical Significance ◽  
Temperature Environment ◽  
Shpb Test ◽  
The Impact ◽  
High Temperature Environment

AbstractConducting experimental studies on the impact compressive mechanical properties of rock under the high temperature environment is of both theoretical value and practical significance to understanding the relationship between the rock under the effect of impact loads and the high temperature environment. Based on the Φ100 mm SHPB and the self-developed Φ100 mm high-temperature SHPB test devices, the impact compressive tests on the sandstone, whether cooling after high temperatures or under real-time high temperatures are carried out. As the test results indicate that since the two high-temperature ways of loading are different from each other, the impact compressive properties of sandstone, after as well as under high temperatures, show different variations along with changes in temperature. Under the effect of the same impact loading rate, there exists a clear critical temperature range in the impact compressive mechanical properties of sandstone after high temperature, and, near the critical temperature, there occurs a significant mutation in the impact compressive mechanical properties. Under high temperatures, however, the impact compressive mechanical properties follow an overall continuity of change except that there are slight fluctuations at individual temperatures.

Effects of Nano-TiO2 on Microstructure and Properties of Ceramic-Lined Composite Steel Pipes Produced by Centrifugal Self-Propagating High-Temperature Synthesis

2013 ◽  
Vol 659 ◽  
pp. 10-14
Author(s):  
Yu Zhu ◽  
Feng Huang ◽  
Yu Xi Ge ◽  
Hong Jun Ni
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Mechanical Tests ◽  
Sem Analysis ◽  
Ceramic Layer ◽  
Temperature Synthesis ◽  
Steel Pipes ◽  
High Temperature Synthesis ◽  
Shearing Strength ◽  
Composite Steel

In order to improve the density and mechanical properties of ceramic-lined composite steel pipes produced by Centrifugal Self-propagating High-temperature Synthesis. Composite steel pipes were prepared by the method of centrifugal-SHS on the basic of Al-Fe2O3 system. With the condition of adding 6% SiO2 and 4% Na2B4O7, the effect of different amount of nano-TiO2 on the density and the mechanical properties of composite steel pipes was studied. By means of SEM analysis, XRD and mechanical tests, the results show that the ceramic layer consists of main crystal phase of α-Al2O3, with small amount phases of FeAl2O4, Al2SiO5 and B2O3. The surface of ceramic layer is smooth, without obvious crack and with good density. The shearing strength of the ceramic layer and the crushing strength of the composite pipe were 13.5 MPa under 8% (in mass) nano-TiO2 and 525Mpa. The density of ceramic layer is up to 94.2% under 8% (in mass) nano-TiO2.

Relations between Microstructure and Mechanical Properties in Laminated Ti-Intermetallic Composites Synthesized Using Ti and Al Foils

2013 ◽  
Vol 592-593 ◽  
pp. 728-731
Author(s):  
Marek Konieczny
Keyword(s):  
Mechanical Properties ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Laminated Composites ◽  
Mechanical Tests ◽  
Microstructure And Mechanical Properties ◽  
Residual Al ◽  
Main Factor

Ti-(Al3Ti+Al) and Ti-Al3Ti laminated composites have been fabricated in vacuum using 50, 100, 150, 200, 400 and 600 μm thick titanium and 50 μm thick aluminum foils. The composites were synthesized with controlled temperature and treating time. Microstructural examinations showed that Al3Ti was the only phase formed during the reaction between Ti and Al. The initial foil thicknesses only affected the volume fraction of the resultant Ti, Al and Al3Ti layers. Treating time at 650 °C was a main factor determining microstructures and properties of the composites. After 20 minutes not all aluminum was consumed and therefore the composites consisted of alternating layers of Ti, Al and Al3Ti. After 60 minutes aluminum layers were completely consumed resulting in microstructures with Ti residual layers alternating with the Al3Ti layers. Mechanical tests were performed on the materials with different microstructures to establish their properties and fracture behavior. The results of investigations indicated that mechanical properties of the composites strongly depended on the thickness of individual Ti layers and the presence of residual Al layers at the intermetallic centerlines.

Mechanical Properties of Glass–Fiber Polyester Reinforced Composites Filled with Nanometer Al2O3 Particles

2012 ◽  
Vol 586 ◽  
pp. 199-205
Author(s):  
Fatemeh Alavi ◽  
Ali Ashrafi
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Fracture Behavior ◽  
Failure Modes ◽  
Glass Fibers ◽  
Weight Percent ◽  
Mechanical Tests ◽  
Nano Particles ◽  
Nano Particle ◽  
Particle Addition

In this research the effects of the nano-particle additions and two different fabric architectures of knitted E-glass fibers on the mechanical properties of polyester fiberglass composites were investigated. The particles selected was 50 nanometer in size Al2O3 particles. E-glass fibers were knitted using two different molds by two different arrangements. Specimens were machined and mechanical tests were conducted as per the accepted test standard. Tension, impact and fracture properties were measured and their associated failure modes were compared with each other. Fracture behavior of specimens with and without nano-particle addition in unidirectional tensile test was studied using Scanning Electron Microscopy (SEM). Results obtained showed that tensile strength of the composite is significantly dependent on nano-particle addition and E-glass fiber architecture. Addition of 0.2 weight percent nano-particles enhances the tensile properties of polyester fiberglass composites. It was found that fracture behavior of composite depends strongly on nano-particle addition.

INFLUENCE OF ADDITIONAL SIZING OF CARBON FIBER IN PRODUCING VOLUME-REINFORCED PREFORMS ON THE PROPERTIES OF HIGH-TEMPERATURE CARBON FIBER

2021 ◽  
pp. 54-65
Author(s):  
A.V. Nacharkina ◽  
◽  
I.V. Zelenina ◽  
M.I. Valueva ◽  
O.G. Voronina ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
High Temperature ◽  
Carbon Fiber ◽  
Moisture Absorption ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Carbon Plastic ◽  
Carbon Plastics ◽  
Operational Factors

Presents the results of experimental studies of the effect of additional apparet on the properties of high-temperature carbon plastic based on a heat-resistant thermosetting phthalonitrile binder and a volume-reinforced woven preform. Comparative data are given on physical and mechanical properties of carbon plastics based on preforms with and without an apparet, including after exposure to operational factors (thermal aging, water and moisture absorption), results of thermal analysis and microstructure research.

scholarly journals The Mechanical Properties of FeAl

1998 ◽  
Vol 552 ◽  
Author(s):  
I. Baker ◽  
E. P. George
Keyword(s):  
Mechanical Properties ◽  
Water Vapor ◽  
High Temperature ◽  
Low Temperature ◽  
Yield Strength ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Room Temperature Ductility ◽  
Equilibrium Vacancy ◽  
Made In

ABSTRACTIn the last few years, considerable progress been made in obtaining reproducible mechanical properties data for binary FeAl alloys. Two sets of observations are the foundation of this progress. The first is that the large equilibrium vacancy concentrations that exist in FeAl at high temperature are easily retained during cooling, and that these strongly affect the low-temperature mechanical properties. The second is that room-temperature ductility is adversely affected by water vapor. The purpose of this paper is to highlight our understanding of key phenomena and to show how an understanding of the factors which control the yield strength and fracture behavior has followed from the discovery of the above two effects.

scholarly journals FRACTURE BEHAVIOR OF FeAlSi INTERMETALLICS

2020 ◽  
Vol 27 ◽  
pp. 6-12
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Kateřina Nová ◽  
Filip Průša ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Chemical Composition ◽  
Fracture Resistance ◽  
Fracture Behavior ◽  
Intermetallic Alloy ◽  
Mechanically Alloyed ◽  
Plasma Sintering ◽  
Potential Applications ◽  
Spark Plasma

The study is devoted to the intermetallic alloy FeAl20Si20 (wt.%) with the potential applications in high temperature aggressive environments. The samples of the same chemical composition were prepared by spark plasma sintering from the different mechanically alloyed powders (pure elements and pre-alloyed powders). Differences in mechanical properties were characterized. Whereas no significant differences were found in hardness and Young´s modulus, fracture resistance was higher for the samples from pre-alloyed powders in which Palmqvist and lateral cracks were observed (contrary to the sample made of pure elements where only Palmqvist cracks were identified).

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