Mechanical Behavior of Single‐Crystal and Polycrystalline Cesium Bromide

Plastic‐deformation studies were made of cesium bromide which exhibits no cleavage planes. Single crystals were found to be “soft” and ductile if they were favorably oriented relative to the loading axis to activate the {110}∝001〈 slip systems. Kink bands were formed by applying a compressive load normal to a {100} plane. Cross slip was found to occur during deformation at all test temperatures. Tensile loads applied normal to {100} and {110} planes caused fracture along {110} planes, whereas compressive loads normal to {100} planes forced fracture along {112} planes. The ductility of polycrystalline cesium bromide was found to be limited because of the lack of five independent slip systems. The specimens with smaller grains showed less strain at fracture and greater strain hardening than the larger‐grained specimens. The mechanism fracture was intergranular up to 300° C.