Effect of moulding pressure, cooling rate and curing temperature on the properties of rocket insulator compound

1987 ◽  
Vol 6 (10) ◽  
pp. 1117-1122 ◽  
Author(s):  
A. Saha Deuri ◽  
Anil K. Bhownick ◽  
B. John ◽  
T. S. Ram
Keyword(s):  
Cooling Rate ◽  
Curing Temperature ◽  
Moulding Pressure ◽  
Insulator Compound

Mechanical properties of carbon nanotubes/epoxy nanocomposites: Pre-curing, curing temperature, and cooling rate

2021 ◽  
pp. 095400832199209
Author(s):  
Hermawan Judawisastra ◽  
Christian Harito ◽  
Dika Anindyajati ◽  
Hengky Purnama ◽  
Akbar Hanif Dawam Abdullah
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Cooling Rate ◽  
Resin Acid ◽  
Diglycidyl Ether ◽  
Curing Temperature ◽  
Pull Out ◽  
Multi Walled Carbon Nanotubes ◽  
Mechanical Properties Characterization ◽  
Walled Carbon Nanotubes

The effects of composite fabrication, such as pre-curing, curing temperature, and cooling rate, were studied. In this work, the pre-curing was defined as heat treatment of Multi-Walled Carbon Nanotubes (MWNCTs) with Diglycidyl Ether of Bisphenol A (DGEBA) epoxy resin. Acid purified MWCNTs were characterized by Raman spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The pre-curing facilitated bonding between MWCNTs and epoxy via the oxirane ring of DGEBA, which accelerated the curing process of epoxy and increased mechanical properties. The elevated curing temperature on the pre-cured sample further improved the composite’s mechanical properties by increasing interfacial bonding due to cross-linking. The rapid cooling using liquid nitrogen during pre-curing treatment prevented re-agglomeration of MWCNTs, showing smaller agglomerates and improving the mechanical properties. Agglomeration was characterized by scanning electron microscopy, while the bonding between MWCNTs and epoxy was examined by the length of fibre pull-out on the fracture surface. Tensile testing was deployed for mechanical properties characterization. The degree of cure was determined by FTIR and Differential Thermal Analysis (DTA).

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

Suppression of γ’ Precipitation in a Laser-Melted Nickel-Base Alloy

1977 ◽  
Vol 35 ◽  
pp. 270-271
Author(s):  
J. M. Walsh ◽  
J. C. Whittles ◽  
B. H. Kear ◽  
E. M. Breinan
Keyword(s):  
Cooling Rate ◽  
Base Alloy ◽  
Material Surface ◽  
Intimate Contact ◽  
Absorbed Power ◽  
Perfect Contact ◽  
Nickel Base ◽  
Rapidly Solidified ◽  
Limiting Case ◽  
The Heat Transfer Coefficient

Conventionally cast γ’ precipitation hardened nickel-base superalloys possess well-defined dendritic structures and normally exhibit pronounced segregation. Splat quenched, or rapidly solidified alloys, on the other hand, show little or no evidence for phase decomposition and markedly reduced segregation. In what follows, it is shown that comparable results have been obtained in superalloys processed by the LASERGLAZE™ method.In laser glazing, a sharply focused laser beam is traversed across the material surface at a rate that induces surface localized melting, while avoiding significant surface vaporization. Under these conditions, computations of the average cooling rate can be made with confidence, since intimate contact between the melt and the self-substrate ensures that the heat transfer coefficient is reproducibly constant (h=∞ for perfect contact) in contrast to the variable h characteristic of splat quenching. Results of such computations for pure nickel are presented in Fig. 1, which shows that there is a maximum cooling rate for a given absorbed power density, corresponding to the limiting case in which melt depth approaches zero.

Voids in Quenched Nickel

1968 ◽  
Vol 26 ◽  
pp. 266-267
Author(s):  
J. J. Laidler
Keyword(s):  
Electron Beam ◽  
Ambient Temperature ◽  
Cooling Rate ◽  
Three Dimensional ◽  
Cooling Curve ◽  
Polycrystalline Nickel ◽  
Quenching Temperature ◽  
Long Tail ◽  
Diffusion Pump

The presence of three-dimensional voids in quenched metals has long been suspected, and voids have indeed been observed directly in a number of metals. These include aluminum, platinum, and copper, silver and gold. Attempts at the production of observable quenched-in defects in nickel have been generally unsuccessful, so the present work was initiated in order to establish the conditions under which such defects may be formed.Electron beam zone-melted polycrystalline nickel foils, 99.997% pure, were quenched from 1420°C in an evacuated chamber into a bath containing a silicone diffusion pump fluid . The pressure in the chamber at the quenching temperature was less than 10-5 Torr . With an oil quench such as this, the cooling rate is approximately 5,000°C/second above 400°C; below 400°C, the cooling curve has a long tail. Therefore, the quenched specimens are aged in place for several seconds at a temperature which continuously approaches the ambient temperature of the system.

Microstructures of Laser Processed Fe-Cr Surface Alloys

1981 ◽  
Vol 39 ◽  
pp. 328-329
Author(s):  
P. A. Molian ◽  
K. H. Khan ◽  
W. E. Wood
Keyword(s):  
Cooling Rate ◽  
Pure Iron ◽  
Continuous Wave ◽  
Laser Surface ◽  
Material Surface ◽  
Constitution Diagram ◽  
Incident Power ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Normal Concrete ◽  
Astm Method ◽  
Additive Type ◽  
Composition Variation ◽  
Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

SINTESIS DAN MODIFIKASI STRUKTUR DAN PORI MEMBRAN KITOSAN TERCROSSLINK UNTUK STERILISASI MEDIA PERTUMBUHAN BAKTERI

2019 ◽  
Vol 3 (2) ◽  
pp. 27
Author(s):  
Emma Savitri ◽  
Natalia Suseno ◽  
Tokok Adiarto
Keyword(s):  
Tensile Strength ◽  
Chitosan Solution ◽  
Curing Temperature ◽  
Growth Media ◽  
Optimum Conditions ◽  
Separation Processes ◽  
Crosslinking Process ◽  
Chitosan Membrane ◽  
Chitosan Membranes ◽  
Crosslinked Chitosan

Many mass-transfer applications have used chitosan membrane in separation processes. This research applied crosslinked chitosan membrane to sterillize bacterial growth media. Chitosan membranes having 79 % DD were produced by casting and drying chitosan solution. The images of the membrane were characterized by SEM and other characterizations such as permeability, permselectivity and tensile strength were investigated. The flux increased with longer submersion period but the rejection decreased. Otherwise, the flux decreased and rejection increased in line with an increase in curing temperature. Tensile strength increased with the increase of submersion period and curing temperature. The optimum conditions of crosslinking process are 2 hours of submersion periods and curing temperature at 90 oC.  It gives flux 5.8930 L/jam.m2, rejection 97.47 % and tensile strength 49640 kN/m2

STUDY OF THE DEPENDENCE OF THE CRYSTALLIZATION PROCESSES OF POLYMER MICROCOMPOSITES ON THE COOLING RATE

2017 ◽  
Author(s):  
◽  
Nataliia Fialko ◽  
Viktor Prokopov ◽  
Julii Sherenkovskiy ◽  
Nataliia Meranova ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Crystallization Process

The analysis of the effect of the cooling rate on the main parameters of the crystallization process from the melt of composites obtained based on various matrices - polyethylene, polypropylene and polycarbonate, using copper microparticles as a filler is carried out.

Sign in / Sign up

Export Citation Format

Share Document