论文部分内容阅读
The fatigue crack propagation rate of an as-extruded AZ31B magnesium alloy was studied. Compact tension [C(T)] of the specimens at the incision direction parallel (T-L), vertical (L-T), and inclined at 45o to the extrusion direction was investigated. Results indicate that the crack propagation direction is parallel to the extrusion direction for T-L and L-T specimens, whereas the specimen inclined at 45o has an angular deflection of 9° to 11° toward the extrusion direction. The T-L specimen has the fastest fatigue crack propagation rate, and the L-T direction has the slowest rate. The fatigue crack propagation rate of the specimen inclined at 45o is between those of the T-L and L-T specimens. The crack tip propagates by both transgranular and intergranular fractures. Fatigue fracture consists of quasi-cleavage and is a brittle type of fracture.