Effects of hot working on the martensitic transformation of Ni-Ti alloy

Journal Article · Fri Apr 15 00:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90549-5· OSTI ID:5228300

Jean, Render; Tsai, Jongcheng ^[1]

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1. Industrial Technology Research Inst., Hsinchu (Taiwan, Province of China). Materials Research Lab.

Among shape memory alloys, Ni-Ti alloys of near-equiatomic composition have been used for various commercial applications, since they have good mechanical properties and well-known shape memory effects. Processing disadvantages, however, include the difficulties and expenses of processing. Moreover, cold working to high reduction is difficult and expensive because limited cold workability and high work hardening, makes hot working indispensable. Therefore, optimization of hot working parameters and control of shape memory behavior is necessary. It is generally known that the influence of work hardening and subsequent isothermal annealing on the stability of the individual phases formed in Ni-Ti shape memory alloys has been investigated. Work hardening promotes the formation of the rhombohedral R phase. The matrix work hardening suppresses the phase transformation B2[leftrightarrow]B19[prime]. In this study, the equiatomic Ni-Ti alloy is plastic deformed by hot compression at various temperatures. The effects of hot compression on the martensitic transformation are investigated with differential scanning calorimeter measurements and hardness tests. The optimal hot working temperature range is also discussed.

• OSTI ID: 5228300
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 30:8; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NICKEL ALLOYS
CRYSTAL-PHASE TRANSFORMATIONS
HOT WORKING
TITANIUM ALLOYS
EXPERIMENTAL DATA
MICROSTRUCTURE
ALLOYS
DATA
FABRICATION
INFORMATION
MATERIALS WORKING
NUMERICAL DATA
PHASE TRANSFORMATIONS
360102* - Metals & Alloys- Structure & Phase Studies
360101 - Metals & Alloys- Preparation & Fabrication