Shockley-type partials

Fig. 39. Model of how a basal-plane, unit strength, dislocation of the type Ja has dissociated into two Shockley partials of Burgers vector Ja lOTO> and Jo .

The I2 BSFs have an. .. ABABCACA... sequence and are formed by a 1/3(1100) shear of one part of the crystal with respect to the other or by dissociation of a perfect dislocation with Burger s vector b = 1/3(1120) into two Shockley partials, with b = 1/3(1100) at hoth ends. The -type BSF with... 

The density of partial dislocations allows us also to estimate that the density of Ii-type BSFs is one order of magnitude larger than the density of l2-type faults. However, occasionally it is possible that two Ii faults with different Burgers vectors meet each other, resulting in the appearance of one Shockley partial dislocation instead of two Frank-Shocldey dislocations. This special case is illustrated in Figure 10.8. 

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