Shape memory alloy element.

摘要

A memory element made of a shape-memory alloy includes lead-attachment (28) and shape-memory portions (30) and a partition interconnecting such portions (26). The lead-attachment (28) and shape-memory (30) portions are comprised of characteristic internal structures, while the partition (26) is comprised of an internal structure dissimilar to the characteristic internal structure of at least one of the lead-attachment and shape-memory portions. Shape-memory effect characteristics of the shape-memory portion are preserved to maintain the memory function of the memory element by configuring the dissimilar internal structure to block transmigration from the lead-attachment to the shape-memory portions of selected contaminant material existing in the lead-attachment portion. The partition (26) functions as a contaminant filter to control the concentration of contaminant material in the shape-memory portion (30), thereby enhancing the durability of the memory element. A method is disclosed of altering the first crystalline structure of an uncontaminated memory element to provide the dissimilar, contaminant migration-blocking, internal structure.