Solid solution softening

In contradistinction, Ti2AlCo.5No.5, is harder, more brittle and significantly stronger, than the end members Ti2AlC and Ti2AlN, which can be deformed plastically up to 5% strain, even at room temperature [98]. At a temperature of 1200 °C, a solid solution softening effect is observed, the reasons for which are still unclear, although they may be related to the aforementioned interlaminar decohesions. 

Figure 4.4. Schematic representation of solid solution softening versus an intrinsic electronic effect. After Gypen and Deruyttere. ...

As Figure 4.4 shows, a hardness minimum occurs at a critical electron concentration in those cases where solid solution softening occurs, and simple relationships can be developed to predict the softening effect... 

Diaza-l 8-crown-6 has also been converted into polymeric materials by the reaction of 9 with toluenediisocyanate . The polymeric materials were prepared by stirring commercially available 9 with TDI in dichloromethane solution. Reaction was rapid and exothermic, but the mixture was not worked up until the next day. The product was a white solid which softened between 170—190° and decomposed between 250—270°. 

Alternatively, potable water can be extracted from seawater by freezing salts, which depress the freezing point of water, remain in the liquid phase. Generally, though, it is more practical to remove the relatively small amount of solutes (typically, 0.02% for river water) from the great excess of water, rather than vice versa. Seawater is an exceptional case, with about 3.5% dissolved solids. Water softening is concerned primarily with removal of Ca2+ and Mg2+, but for some purposes removal of all dissolved solids (deionization or demineralization) is necessary. 

The substance, which is of a type general to the sulphur group (see pp. 6, 338), is a red solid which softens at 30° C. without melting. It is decomposed by water mainly into tellurium and sulphuric acid, whilst in solution in sulphuric acid it undergoes oxidation into basic tellurium sulphate on warming. Between 35° and 90° C. it is stated that the red compound is converted into an isomeric form having a reddish-brown colour.7 (See also p. 379.)... 

O Neil (1967) analysed the influence of alloy admixtures in small amounts, e g-, 5% copper, in very hard a-manganese on the softening of the solid solution in order to raise its compliance to electrolytic polishing. 

NHCONHCOC(CH3)C2H5, and formaldehyde. Properties Clear, pale, solid resin. Softening point (B R) 85C, d 1.30, pH (10% aqueous solution) 6.5-7.5. 

A correct definition of dry has already been commented upon because even the most hydrophobic organic substances, e.g. polystyrene, absorb water vapour to some extent. Water has therefore been called Nature s ubiquitous plasticiser . Apart from this softening role, water, being itself a very reactive and versatile molecule, might also have other effects on amorphous solid substrates, some of them unexpected, and most of them deleterious. The role of low water contents (< 1 % w/w) in affecting the behaviour of solid solutions is a subject that deserves further investigation. 

Because we have earlier included long-term delays based on the dissolution or softening of celluloid, it should be pointed out that this solid solution of nitrocellulose and camphor alters its physicochemical behavior with time, i.e. with loss of camphor, but a plateau of stability seems to be reached after some aging. 

The y-phase is a solid solution with a face-centered crystal lattice and randomly distributed different species of atoms. By contrast, the y -phase has an ordered crystalline lattice of II2 type (Figure 10.2). In pure intermetallic compound NisAl the atoms of aluminum are placed at the vertices of the cubic cell and form the sublattice A. Atoms of nickel are located at the centers of the faces and form the sublattice B. The y -phase has remarkable properties, in particular, an anomalous dependence of strength on temperature. The y -phase first hardens, up to about 1073 K, and then softens. The interatomic bondings Ni-Al are covalent. 

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