Tilt Boundary

          This is another type of surface defect called low-angle boundary as the orientation difference between two neighboring crystals is less than 10°. This is why the disruption in the boundary is not so drastic as in the high angle boundary. This type of boundary is associated with relatively little energy and is composed of edge dislocations lying one above the other. In general, one can described low-angle boundaries by suitable arrays of dislocation. The angle or tilt, 

Where b is the magnitude of Burgers vector, and

            D is the average vertical distance between dislocations.