Segregation matrix

Here m moles of the ith species are present in separation vessel B having two regions 7 = 1 and 2. Further, Yg + Yi2 = 1. For a two-component system with f = 1, 2, one may define a segregation matrix [y ] as well as the corresponding matrix for mole numbers... 

The second application was checked in a feasibility study. The preliminary results show that segregations in Inconnel IN 718 can be detected within the volume. It can be assumed that segregations also in other type of material can be detected by this method. Several details, however, have to be checked before a routine use of this susceptibility based method. Among these details are to determine the susceptibility contrast of v ious segregations in various matrix materials as well as sizing and localisation procedures of the segrations. 

Above the solution treatment temperature (ca 1250°C), the alloy is single phase with a bcc crystal stmcture. During cooling to ca 750—850°C, the sohd solution decomposes spinodally into two other bcc phases a and lattice parameter composition. The matrix a-phase is rich in Ni and Al and weakly magnetic as compared with which is rich in Fe and Co. The a -phase tends to be rod-like in the (100) dkection and ca 10 nm in diameter and ca 100 nm long. As the temperature is decreased, segregation of the elements becomes mote pronounced and the difference between the saturation polarizations of the two phases increases. 

The lead-base babbitts ate based upon the lead—antimony—tin system, and, like the tin-base, have a stmcture of hard crystals ia a relatively soft matrix. The lead-base ahoys ate, however, mote prone to segregation, have a lower thermal conductivity than the tin-base babbitts, and ate employed genetahy as an iaexpensive substitute for the tin-base ahoys. Properly lined, however, they function satisfactorily as beatings under moderate conditions of load and speed. 

We will limit ourselves to the surface segregation energy of an impurity of atomic number Z + 1 in a BCC matrix of atomic number Z and study the variation of this energy as a function of the number Nj of d electrons per atom in the d band of e transition metal Z. 

Figure 2. Segregation energy in layer Sp (p = 0 surface layer...) of a transition metal impurity of atomic number Z + 1 (d band-filling (Nj + l.l)e /atom, full curves (Nj + l)e /atom, dashed curve) in a BCC transition metal matrix of atomic number Z (d band-filling Nje" /atom) for various crystallographic orientations of the surface...

Theoretical calculations suggest that the segregation and ascent time scales for basaltic magmas from a partially molten matrix are likely to be short (McKenzie 1985). 

In Sn/V/Nb/Sb/O catalysts, different compoimds form (10) mtile Sn02 (also incorporating Sb, Sb/Nb mixed oxide and non-stoichiometric mtile-type V/Nb/Sb/O the latter segregates preferentially at the smface of the catalyst. Tin oxide (cassiterite) provides the matrix for the dispersion of the active components therefore, a variation of the value of x in Sn/V/Nb/Sb x/0.2/1/3 catalysts imphes a... 

If N is the total number of detected atoms of the segregating element i, N the total number of atoms detected, cm the matrix concentration of the element, then... 

Figure 5.43. The Cu L2,3 edge of a Sb-segregated grain boundary compared with the Cu matrix.

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