Temperature homologous

Ashby also constructed sintering maps in which x/a is plotted versus the homologous temperature T/Tm where Tm is the melting point. These maps, which must be drawn for a given initial radius of the sintering particles, use the relevant diffusion and vapour pressure data. Isochrones connect values of x/a which can be achieved in a fixed time of annealing as a function of the homologous temperature. 

Homologation, of boronic esters, 23 671 Homologous enzyme structures, 10 337 Homologous promoters, 22 453 Homologous recombination, 22 459-460 Homologous temperature, 23 487 Homology, of proteins, 20 833-834... 

At temperatures below the homologous temperature (Thomo 0.25rmeit), however, the deformation processes are predominantly controlled by dislocation glide ... 

For temperatures well below the homologous temperature, the steady-state creep rate is well represented by Eqn. (6.3). By substituting Eqn. (6.3) into Eqn. (6.13), the steady-state creep crack growth rate becomes ... 

Equation 6.14 provides a formal connection between creep crack growth and the kinetics of creep deformation in that the steady-state crack growth rates can be predicted from the data on uniaxial creep deformation. Such a comparison was made by Yin et al. [3] and is reconstructed here to correct for the previously described discrepancies in the location of the crack-tip coordinates (from dr/2 to dr) with respect to the microstructural features, and in the fracture and crack growth models. Steady-state creep deformation and crack growth rate data on an AlSl 4340 steel (tempered at 477 K), obtained by Landes and Wei [2] at 297, 353, and 413 K, were used. (AU of these temperatures were below the homologous temperature of about 450 K.) The sensitivity of the model to ys, N, and cr is assessed. 

Figures. Yield stress and deformability as a function of homologous temperature TJT (with = melting temperature) for various materials with different types of atomic bonding (Westbrook, 1965).

Nickel base materials have outstanding resistance to thermal, mechanical, and corrosive stresses. They include up to 15 elements with a portion of more than 50 % in weight and are able to resist long-term stresses up to a homologous temperature, which is the ratio between the temperature load and the melting temperature, of approximately 0.85 (Buergel 2006). Nickel base materials are used in gas turbines, jet engines, space vehicles, and many more modem applications with extreme conditions. 

Anand, L. and Su, C. (2007) A constitutive theory for metallic glasses at high homologous temperatures, Acta Mater., 55, 3735-3747. 

Homologous temperature n. The ratio of the absolute temperature of a material sample to the absolute temperature at which the material melts. 

Fig. 5.12 Grain-boundary mobility of TZP and CSZ plotted versus reciprocal homologous temperature (Tm is the melting point) [3]. With kind permission of John Wiley and Sons...

MgO was mentioned in Chap. 5, Sect. 5.2.2 as being ductile at ambient temperature, thus undergoing plastic deformation. Having a high melting point of 2798 °C, it is expected that creep may occur at high homologous temperatures. In... 

Second harmonic microscopy was used to study In diffusion on (111) surfaces. It was found that, for homologous temperatures that were near to 0.5 and for coverages ranging from 0 to 0.7, the In diffusivity could be described by ... 

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