Dominant factors for fracture at the micro-scale in electrodeposited nickel alloys.

Two different LIGA electrodeposited nickel alloys displayed distinct fracture modes after meso-scale tensile testing. The Ni-Co alloy failed in a ductile manner, while the Ni-Fe alloy failed in a more brittle-appearing manner. Various factors affecting the fracture are discussed; it was determined that the fracture mode did not depend upon the strain rate but did depend upon the sample geometry. The difference in the microstructure is likely the cause of the difference in fracture mode, as the Ni-Co alloy is fine-grained, while the Ni-Fe alloy is nano-grained and likely failed by a creep-like mechanism.