Effect of thermal treatment on the microstructure of polycrystalline silver halide fibers

The silver halide fibers were made by hot extrusion. The microstructure of the fibers changed after thermal treatment at different temperatures. SEM micrographs showed that the microstructure of the fibers did not change when temperatures of thermal treatment T < 170<degrees>C, and their grain sizes were 1 similar to2 mum. The grain size grew up when T > 170 degreesC. The relation of grain size and T was as follows: 10 similar to 20 mum, T = 200 degreesC; 20 similar to 30 mum, T = 250 degreesC; 30 similar to 40 mum, T = 300 degreesC, respectively. The measurements of microhardness also showed that the microhardness of the fibers decreased as temperatures of thermal treatment increased when T > 170 degreesC and the lowest microhardness appeared at 200 degreesC.