Hardness variation

Glazov and Vigdorovich (1969) proceeded from the findings of Kurnakov and Zhemchuzhnyi (1908), which were consistent with the law of Vegard laid down later in 1917. They established on the basis of a number of examples a full linear dependence of hardness variation in metals and semi-conducting compounds (as solid solutions) on variation in chemical composition. 

This underlies of the possibility of using hardness variation tests to determine the phase transformation curves in component diagrams (Figs. 5.9, 5.10). 

Fig. 5.14. Hardness variation as a function of copper content of aluminium alloy with 2% Cu with distance from grain boundary.

Fig. 4.5.5. Mohs hardness variation in most common types of rocks.

Fig. 5.9. Diagram of hardness variation in the system of a continuous series of solid solutions.

Similar relations were obtained in tests of three-component systems. It should be noted that analysis of hardness variation with composition is possible only in the case of additive hardness increment as a function of concentration. For low concentrations of admixtures, usually below 5%... 

In processing polyurethanes, the hardness is not greatly affected by the mixing ratios. A material mixed at 80% of the theoretical curative level has greatly different overall properties to one mixed at 100%. The hardness is still at the same level. Figure 7.6 shows the hardness variations with different curative variations. 

Weight and hardness variation are common problems experienced when tableting. Tablet weight is mainly affected by factors such as powder variation, tablet press condition and tooling, and flow of powder on the tablet press. 

Figure 8. Hardness variations across samples treated at different temperatures...

Fig. 4.14 (a) Nugget grain size vs. rotation speed and (b) nugget center and heat-affected zone (HAZ) minimum hardness variation as a function of rotation speed with constant welding speed and z-axis force, Fz... 

The work of Bussu and Irving on 6.35 mm (0.25 in.) thick 2024-T351 Al sheet is illustrative of hardness variations following FSW in 2024-T351 Al (Ref 12). In their work (Fig. 5.3), hardness is illustrated both as a function of distance from the joint interface and depth from the top surface. As shown, a typical W -shaped hardness curve is created. Due to the close relationship between hardness profiles and tensile test results, this composite of hardness results has implications for resultant mechanical properties. The studies in this work show four distinct hardness zones ... 

Surface hardness data for 2219-T8751, an aluminum-copper alloy, illustrate a similar W -curve response to FSW (Fig. 5.5) (Ref 24). As before, the hardness variation shown in Fig. 

The term surface integrity in the cmitext of machined surfaces was launched by Field and Kahles in the middle of the 1960s (Field and Kahles 1964). Subsequently more and more publications made use of this expression understanding plastic deformation, microcracking, phase transformations, hardness variations, tears and laps, residual stresses etc. as typical measures to investigate. 

Atomic force microscopy has been combined with nano-indentation measurements to map hardness variations on the surface of a CaCOg-filled sample of PDMS. ° In another application, PDMS-modified tips were used to obtain friction coefficients involving self-assembled monolayers. ... 

In Fig. 1.56, graphs show the Vickers hardness variations for several refractory carbides under loads. These experiments were performed for a wide range of test forces, between 0.49 N and 196 N. All three graphs below show the same pattern... 

Rahmoun K et al (2009) A multilayer model for describing hardness variations of aged porous silicon low-dielectric constant thin films. Thin Solid Films 518 213-221 Rice RW (ed) (1998) Porosity of ceramics. Marcel Dekker, New York... 

TABLE 3.32 Coefficients of the Correlation of the Variation of the Total Energies of the Table 3. 28 With the Finite-Difference Electronegativity and Hardness Variations of the Table 3.31 in Experimental, Density Functional, and Semiclassical Models of Chemical... 

Most roll cover manufacturers carry out their own robber compounding because of the variety of the formulations, the demand for high quality and the small batch sizes. Mixing of the compounds is frequently done on open mills (Fig. 6.9) due to the small batch sizes, the high number of different compounds as well as hardness variations and the good quality of this compounding procedure. The use of internal mixers is not always justified due to high equipment costs. 

Fretting corrosion. The relatively good resistance of cast irons to fretting corrosion is influenced by such variables as lubrication, hardness variations between materials, the presence of gaskets, and coatings. 

Here, i/gph is the hardness value of the spherulites, is the hardness of the amorphous interspherulitic regions, and is the volume fraction of crystallized spherulites. During primary crystallization, Hgph remains constant and hardness is directly proportional to the volume occupied by the spherulites (12). The hardness variation in the course of isothermal crystallization of PET and poly(ethylene naphthalene-2,6-dicarboxylate) (PEN) has been shown to follow Avrami law (13,14). 

---