Hardening solid solution

Another important way of strengthening metals is to alloy them with elements that are dissolved in the crystal lattice and form a solid solution. Such atoms 

A further interaction between the dislocation and the solid solution atom is due to the different strength of the atomic bond between the dissolved atom and its neighbours, resulting in a locally changed elastic modulus in the vicinity of the solid solution atom. The line tension of the dislocation thus either increases or decreases when it approaches the atom, causing another obstacle effect known as modulus interaction. 

Short-range order interaction [40] (sometimes called configurational interaction or Fisher effect) can also occur. If, for example, the binding energy 

Experimentally, the following relation between the contribution to strengthening Aasss and the concentration c of the impurity atoms is found  

The exponent n takes values of about 0.5. This is plausible because the spacing of the obstacles decreases approximately with as we will see in section 6.4.4 (equation (6.28)).  

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Bragt R. C., 1967, Chromium Oxide Solid Solution Hardening of Aluminium Oxide, J. Am. Cer. Soc., 50-54. 

Iron-niekcl base superalloys were developed primarily from the stainless steels. In the United Slates, these alloys included 19-9 DL. lb-25-6, and A-286, Luler, higher nickel contents were employed to take advantage of the superior oxidation resistance of nickel and the beneficial effects of y -forming elements. All iron-nickel base superalloys rely on solid solution hardening lo some extent. 

Wrought heat-treatable Al alloys contain Mg, Zn, and Cu on the level of several percent as precipitation and solid solution hardening ingredients. The precipitation process forms nanometer size Guinier Preston (GP) zones that are coherent with the matrix and produce the age-hardening effect... 

For this analysis, symmetrical parts have been considered Figure 7 shows the contour plot of Oy stress. As expected the Ni-rich layers at the surfaces are under compression and the Copper -rich layers in the central part under tension. The peak values varies between 100 and -100 MPa. From the contour plot of the plastic deformation shown in figure 10, we can see that all of them occur in the pure metal layers in both Ni and Cu. This is explained by the low yield strength of pure Cu and Ni which are soft metals as compared to the solid solutions hardened CuNi alloys. 

H. Kokawa, Microstructural Factors Governing Hardness in Friction-Stir Welds of Solid Solution Hardened A1 Alloys, Met-all. Mater. Trans. A, Vol 32, Dec 2001, p 3033-3042... 

The nickel base alloys are produced from a group of alloys which have chemical compositions generally over 50 % nickel and less than 10 % iron. They are mainly strengthened by intermetallic precipitation in an austenitic matrix. The cobalt base alloys have a high Co content (40 to 70 %X high Cr (over 20 %), high W (7 to 15 %) and they are strengthened by a combination of carbides and solid solution hardeners. 

In 2007, Bhatt and Desiraju reported that the five different solid forms of opremazole have varying proportions of the 5-methoxy and 6-methoxy tautomers. Only one form is the pure 6-methoxy tautomer, while all other forms are mixture of 5- and 6-methoxy tautomers ranging from pure to a 15 85 mixture of 5-methoxy- 6-methoxy opremazole (2007CC2057). Solid-solution hardening of molecular crystals in connection with tautomeric polymorphs of opremazole has been discussed (2015JA1794). 

Solid solution hardening is observed for BagNixSi46-x. where the Vickers hardness increases with increasing Ni-content, x. This exceptional behavior is also reflected by a decrease of the lattice parameter with increasing transition metal content [32, 52], whereas in case of BagPdxSi46.x [134] the lattice parameter (increase) and HV (decrease) exhibit converse dependences as a function of x. 

Allen et al [130,131] showed that boron vapor increased the modulus and conductivity (Table 5.16) by increasing the crystallinity and helping to prevent shear in the crystallites. It is believed that the boron atoms hinder dislocation in the graphite lattice by a type of hardening process akin to the solid solution hardening effect in metallurgy. 

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