Peculiarities of the recoverable strain variation in the NiTi alloy produced by wire arc additive manufacturing

Abstract

Peculiarities of the recoverable strain variation on cooling and heating under a stress was studied in the NiTi sample produced by wire arc additive manufacturing (WAAM). The strain variation occurred in some stages due to the layers underwent the martensitic transformations at different temperatures. The recoverable strain on cooling and heating under a stress of the NiTi WAAM sample was three times less than in the alloys produced by conventional technology. This may be caused by texture that is characterized by the smallest recoverable strain. The sample fracture occurred on cooling under 400 MPa in the middle part of the second layer due to the formation of cracks in the brittle Ti2Ni precipitates.