Annealed specimens

Cobalt cannot be classified as an oxidation-resistant metal. Scaling and oxidation rates of unalloyed cobalt in air are 25 times those of nickel. The oxidation resistance of Co has been compared with that of Zr, Ti, Fe, and Be. Cobalt in the hexagonal form (cold-worked specimens) oxidizes more rapidly than in the cubic form (annealed specimens) (3). 

Figure 11. Phase reconstruction of the whole hologram of image shown in Figure 10 showing that some pores still exist in the thermically annealed specimen. Phase map is displayed in (a) together with a line-scan averaged over a width of 30 pixels (c) and a surface plot (b) taken from a smaller region of (a). The surface plot has been heavily noise filtered through Gaussian smoothing to better display the holes shape.

Figure 11. XRD patterns of annealed specimens of leached AhsCoioAgis...

Takeda et at. (19) heat-treated the wet fibrous specimen in a sealed bomb in the presence of water. At temperatures above 120°C the annealed specimen showed a remarkably different X-ray fiber diagram (Fig. 9) the first layer disappered, the fiber... 

Quenched specimens given a brief thermal annealing at 140 °C for 10 minutes were found to exhibit toughness similar to that observed for as-postcured specimens (Table 1). Even though the strength for 10 minutes annealed specimens was not... 

Nonstoichiometry in Rare Earth Oxide Systems. As more work is done on the intermediate oxides at low temperatures, regions earlier thought to be non-stoichiometric are resolved into phases of narrow composition limit. It is possible that for carefully annealed specimens the entire range of composition will be resolved into definite compounds of narrow composition limits separated by two-phase regions. This, of course, presumes that equilibrium can be achieved. 

The Mechanism of Corrosion.—An attractive theory of the mechanism of corrosion has been outlined by Aitchison.2 Compact iron, when examined under the microscope (see Part III.), is seen to consist of crystals of ferrite separated from each other by an amorphous cement. It is reasonable to suppose that the solution pressure of this cement differs from that of the ferrite, for differences of this kind invariably occur between amorphous and crystalline varieties of substances. Upon immersion in an electrolyte, therefore, such as ordinary tap water or aqueous solutions of inorganic salts, a difference of potential exists leading to corrosion. If the cement is positive to the ferrite, it is the cement that will oxidise away and vice versa. In a perfectly annealed specimen, in which there is but little mechanical strain, the action will, in the main, be confined to that between the cement and ferrite. If, however, there is any appreciable potential difference between the crystals of ferrite themselves, this will increase the effect, the total observed corrosion being the sum of the two actions. 

For comparing we microscoped in the described manner the specimen of homopolymer of styrene where there is no rubber. In the not annealled specimens of the material the crazes were formed which were the same as those in HIPS (according to their sight).In those annealled at 80 C for 24 hours crazes don t exist. It shows that the cause for forming residual microtension in HIPS is presence of rubber particles in it. 

Figure 19.13 shows the dynamic mechanical properties of such a blend of sPS with a mixture of Kraton G 1651 (15 %) and microsuspension rubber particles (20%) consisting of 60% butyl acrylate (BA) core grafted with 40% styrene shell (S//BA). The glass transition temperatures of the Kraton (-60 °C) and the butyl acrylate (-45 °C) phases can be easily distinguished from one another. The TEM image of such a product after deformation is shown in Figure 19.14. The annealed specimen is shown since the two rubber types are better discernible than in the nonannealed sample. As expected, crazing and voiding in the rubber particles dominate. The product had the following notched impact strengths (ISO 179/eA) injection moulded (80 °C mould temperature) 6.3, injection moulded (140 °C) 4.0 and annealed 3.7kJ/m2.

To check the influences of annealing on the transition behaviors, the as-molded and the annealed specimens of PECs were reheated. Figure 3 showed typical DSC curves for these samples. ... 

The degrees of orientation for the crystallites in the injection-molded specimens of PECs were determined from the azimuthal breadth at half-maximum intensity in the strongest equatorial reflection by X-ray diffraction. Figure 6 showed the degrees of crystallite orientation of the as-molded and the annealed specimens. 

Fig. 13 (a).—X-Ray Diffraction Photograph. Annealed Specimen of Aluminium, Typical Face-Centred Cubic Metal. 

The value of—is becomes larger than that for the solution-annealed specimens in... 

Even with carefully annealed specimens, it is thonght that the equifibriiun melting temperature of the completely crystalhne polymer is never actually attained. The... 

The carbon clusters afford some interesting optical properties to the SiOC and Sic films [79], but are also responsible for the high hardness measured on irradiated films (see Table 4), This is at least two times larger than that of eonventionally annealed specimens, mainly because of the previously mentioned diamond-like nature of the C precipitates in the amorphous SiOC or SiC ceramic matrix of irradiated specimens. The effect depends on the type of irradiating ion, but also on the nature of the side groups of the polymeric chain (CH3 vs. C6H5) [59,60]. The annealing of irradiated films does not seem to affect much their hardness. 

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