Phase diagram lead-substituted

The Zr-Nb phase diagram (Fig. 3.1-91) indicates that a + p microstructures can be obtained at the 2-3 wt% Nb level. This leads to both substitutional solid solution strengthening and dual phase strengthening effects. Oxygen has a high interstitial solubility in a-Zr. Fig. 3.1-92 shows the Zr-O phase diagram. It is inter-... 

Chemical or substitutional disorder results from fractional occupancy of certain lattice sites by different elements of similar metallic radius. This causes a variable amount of these elements in the structure and extends the stability range of the corresponding phase in the phase diagram. In Mg32(Al,Zn)49, for example, three atom sites can be occupied by either A1 or Zn atoms, leading to an extension of the stability range in the Al-Mg-Zn system over a wide spread of values at almost constant Mg content. 

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