Solid solution strengthening metals

The formation of solid solutions of metals is one way to change the properties (generally to increase strength) of the metals. Strengthening metals in this way is known as solid solution strengthening. The ability of two metals to form a solid solution can be predicted by a set of rules known as the Hume-Rothery rules, which can be stated as follows ... 

Figure 8 shows the calculated stress distribution in NiCiluNi part. The peculiar form of the curve is due to the solid solution strengthening effect that occurs while changing from a soft, pure metal to an alloy. In the pure metal layers, the thermal stresses are relaxed by visco-plastic deformation. In the adjacent layers, the yield stresses of the alloys (for example Cu-20Ni and Ni-20Cu) are higher and thus are the residual stresses. 

Solute atoms Solid solution strengthening of metals A 50 Cu-50 Ni alloy has twice the tensile strength of pure copper... 

In summary, we have discussed the three mechanisms that may be used to strengthen and harden single-phase metal alloys strengthening by grain size reduction, solid-solution strengthening, and strain hardening. Of course, they may be used in conjunction with one another for example, a solid-solution strengthened alloy may also be strain hardened. 

Kloske, R.A. Solid solution strengthening and yield drop effects in Au-Ag alloy single crystals containing 1 to 5 and 95 to 99 at. pet. Ag. Trans. Metall. Soc AIME 1969, 245, 217-225. 

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