Problem 1 Two glissile dislocations moving on different slip planes can meet and com- bine to form a third dislocation. In such reactions, the Burgers vectors of the reacting dislocations b and b sum vectorially to give the Burgers vector of the product dislocation, that is, b + b Such a reaction is possible in f.c.c. crystals with (110) {1 1 1} slip systems. A specific case is the reaction involving two dislocations with parallel tangent vectors: b (a/2)[011] moving on (111) b = (a/2)[101] moving on (111) (dislocation 1) (dislocation 2) (a) What is the Burgers vector b3 of the product dislocation? (b) If the dislocations are parallel and moving on the planes given, what is the direction of their tangent vectors? (Hint: this direction must be on both (-1-1 1) and (111) planes) (c) What is the normal to the slip plane of the product dislocation? (Hint: this dislocation (d) Will such dislocation reactions in f.c.c. crystals tend to make slip easier or more difficult? Explain. (Hint: glissile vs. sessile dislocations) has the same t)