Temperature specimens

The resin contained 100.00 parts Epon 828, 80.00 parts NMA and 2.00 parts of BDMA. A part is a unit of mass. This formulation yields a resin with good mechanical performance. The formulation was cured in small test tubes that were placed in an electrically-heated, forced-air circulating oven which was controlled within 0.1°C of the set temperature. Specimens were removed with increasing time, thermally quenched and stored at -25°C. 

After completion of DHC test specimen has been unloaded and cooled down in the furnace to the room temperature. Specimen then has been subjected to cyclic loading to outline the DHC crack and then fractured. After completion of DHC test actual crack length was measured from fractographs (Fig. 2). 

It is equipped with field emission gun (PEG), helium temperature specimen stage, omega-type energy filter and Gatan MegaScan 795 2Kx2K CCD camera. For improved contrast of ice-embedded specimens we employed a novel Zernike-type... 

G. Honjo and M. Watanabe, Examination of cellulose fibre by the low-temperature specimen method of electron diffraction and electron microscopy, Nature, 181 (1958) 326-328. 

Preliminary testing was conducted at room temperature in air and at 77 K with liquid nitrogen surrounding the specimens. At least three specimens were tested at each temperature. Specimens were first cycled once or twice to approximately 50% ultimate load to check the seating of the specimen and to measure the elastic modulus. The ultimate compressive failure zones were generally near one end or the other, but outside the end caps. Failure of the specimens was due to delamination. 

NDT temperature specimens for all three base metals showed no break performance at -196°C. This indicates that the NDT temperatures of all three steels are below —196°C and places LNG service (—162 C) near the NDTT-I-34 C design criterion. This implies that unstable cleavage crack propagation would not occur if the total stress maintained is less than the yield stress. 

Thickness, temperature. Specimen displacement,t displacement record... 

Temperature, Specimen type Crack location K and orientation Stress ratio C n range, MPa m ... 

Compression set is measured at room temperature, and higher or lower temperatures. Cylindrical discs are used as specimens, and these are compressed in special devices using spacers to limit compressioa Typical compression times are 24, 72, 168 h. In the case of testing at room and elevated temperature, specimens are allowed to recover at room temperature and their thickness is measured. This differs from testing at a low temperature where specimens are allowed to recover at test temperature and their thickness is also measured at test temperature at time intervals to obtain a plot of recoveiy vs. time. 

Not unlike the case of superplastic ceramics, ductility and strength relations are influenced by strain rate. The conditions of the experiment must be above the DBT to observe plastic flow, which is different for various ceramics. An illustration of the effect of strain rate and temperature on the strain (ductility) at some stress level can be seen in monolithic Si-C-N. Silicon-nitride-based ceramics are quite promising candidates for mechanical applications at elevated temperatures. Specimens were prepared by hot isostatic pressure (henceforth HIP) of pyrolyzed powder compact at 1500 °C and 950 MPa, without any sintering additives. These compression tests were conducted at temperatures from 1400 to 1700 °C in a nitrogen atmosphere with a servo-hydraulic-type testing machine at constant crosshead speed in an induction heating furnace. In Fig. 2.5, stress-strain curves... 

Specimens are heated by high temperature (approximately 2300 K) tungsten filament lamps that are located outside the quartz tube. Since the spectral response of many materials is different for a radiant heat source at this temperature compared to heat fluxes in fires from sources at much lower temperatures, specimens have to be blackened. In addition, because of the type of heaters that is used and the quartz tube arrangement, the maximum incident heat flux that can be obtained is 70 kW/m. ... 

Figure 6-18. Density as a function of sintering temperature. Specimen were non-isostatic and isostatic pressed at 100/200 MPa and heated at the rate of 5° C/min to the sintering temperature. Holding time at each sintering temperature was 2 h (Reproduced with permission from Ivankovie etal. (2003) J. Eur. Ceram. Soc., 23 283—292 Copyright 2003 Elsevier Science Ltd.).

Air-cooled plate. Solution treated tensile properties of plate specimens air cooled or furnace cooled from various solution temperatures. Specimens were 25 mm (1 in.) plate solution treated 1 h, as 25 by 150 by 150 mm (1 by 6 by 6 in.) specimen blanks. Each data point is the average of... 

Smooth specimens of 63 mm (0 in.) hot roHed plate were tested at room temperature. Specimens were solution treated and aged as fblows H-15Mo3Zr-3AI (UTS, 1421 MPa) 735 (1360 °F), 1 h,... 

The condition of the brazed-on wear pads after irradiations in NRX and Halden has been excellent. Pig. 16. The braze metal fillet has a grey appearance and undergoes a little more corrosion than the can, but the actual penetration Is very small. The H concentration in the wear pad is up to 50 greater than in the can, presumably because of the lower temperature. Specimens having brazed wear pads attached have been irradiated In the Dounreay Fast Reactor (DFR) to total neutron doses of 2.5x10 without any noticeable effects on micro-structure. Mechanical tests on similar samples are being carried out. 

DSC. DSC measures the difference in heat flow between a specimen and a reference as a function of temperature. Specimens are placed in a special pan, which can either be sealed or not. The reference is usually an identical, but... 

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