Menu Selection 10) Sinter a 3-D microstructure to adjust the hydraulic radius of one phase

Following the filtering process (Menu Selection 8), the surface area fractions of the filtered phases (from Menu Selection 9) may not match those of the phases in the starting 2-D SEM images. These surface area fractions can be adjusted using a 3-D "sintering" algorithm to swap specific locations of the two phases in a manner that obtains the desired surface area fractions. Details of the 3-D sintering algorithm have been published previously [9], with the specific application to cement particles described in the CEMHYD3D Version 2.0 user's manual [1].

The input form for Menu Selection 10 is shown in Figure 12. The user must supply a negative integer random number seed, the names of the input and output images, the desired (target) hydraulic radius of the phase being sintered, and the phase IDs of the two phases between which to execute the sintering algorithm. The target hydraulic radius of a phase can be calculated (based on the volume count provided with Menu Selection 9) as [1]:

$$R_h = \frac{6}{4} \times \frac{volume~of~phase~in~pixels}{desired~surface~area~count~in~pixels}.$$ (1)

The factor of 6 over 4 is included to correct for the difference between the approximate surface area of a digitized (pixel-based) sphere and a continuum one of the same diameter. It should be noted that the hydraulic radius of a phase can only be increased when applying the sintering algorithm to it. If it is necessary to decrease the hydraulic radius of a phase, the algorithm should be executed so as to increase the hydraulic radius of the secondary phase, thus decreasing that of the primary one [1].

  

Figure 12: Form to specify inputs to be used in "sintering" a 3-D microstructure.