ABSTRACT

A s with cold deformation, hot deformation is accompanied by damage to the crystal lattice

within grains of M g solid solution. A s imperfections arise, they destroy the arrangement of

the precipitates formed during solid solution decomposition. The places within grains

where the imperfections are concentrated become favoured for precipitates. The next two

micrographs show typical examples of solid solution decomposition in hot deformed M g

alloys. Figure 102e demonstrates preferable precipitation along the sliding bands within the

primary grain of M g solid solution along with grain boundaries. The sliding bands form

after hot deformation and divide the grain into few pieces. Figure 102f demonstrates

Gd-r ich particles precipitated in hot deformed M g - G d alloy. Directions of the plate-like

particles change within the grain following misorientation of the separate grain parts

Figure 102. Light micrographs of the M g - R E alloys, a - M g - 3 mass % Nd, deformed 80% at 350°C, x 1000, b - Mg-13.6 mass % Gd, deformed 40% at 400°C, x240, c - Mg-2 .2 mass % Y, deformed 40% at 450°C, x 240, d - Mg-19.1 mass % Dy, deformed 40% at 500°C, x 250, e - Mg-19.1 mass % Dy, deformed 40% at 350°C, x 1000, f - Mg-21.5 mass % Gd, deformed at 400°C, x 1000.