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Title: Effect of Cu addition on the martensitic transformation of powder metallurgy processed Ti–Ni alloys

Highlights: • M{sub s} of Ti{sub 50}Ni{sub 50} powders is 22 °C, while M{sub s} of SPS-sintered porous bulk increases up to 50 °C. • M{sub s} of Ti{sub 50}Ni{sub 40}Cu{sub 20} porous bulk is only 2 °C higher than that of the powders. • Recovered stain of porous TiNi and TiNiCu alloy is more than 1.5%. - Abstract: Ti{sub 50}Ni{sub 50} and Ti{sub 50}Ni{sub 30}Cu{sub 20} powders were prepared by gas atomization and their transformation behaviors were examined by means of differential scanning calorimetry and X-ray diffraction. One-step B2–B19’ transformation occurred in Ti{sub 50}Ni{sub 50} powders, while Ti{sub 50}Ni{sub 30}Cu{sub 20} powders showed B2–B19 transformation behavior. Porous bulks with 24% porosity were fabricated by spark plasma sintering. The martensitic transformation start temperature (50 °C) of Ti{sub 50}Ni{sub 50} porous bulk is much higher than that (22 °C) of the as-solidified powders. However, the martensitic transformation start temperature (35 °C) of Ti{sub 50}Ni{sub 30}Cu{sub 20} porous bulk is almost the same as that (33 °C) of the powders. When the specimens were compressed to the strain of 8% and then unloaded, the residual strains of Ti{sub 50}Ni{sub 50} and Ti{sub 50}Ni{sub 30}Cu{sub 20} alloy bulks were 3.95 and 3.7%, respectively.more » However, these residual strains were recovered up to 1.7% after heating by the shape memory phenomenon.« less
Authors:
 [1] ;  [2]
  1. Department of Advanced Materials Engineering, Keimyung University, 1000 Shindang-dong Dalseo-gu, Daegu 704-701 (Korea, Republic of)
  2. Department of Civil Engineering, Hongik University, 72-1 Sangsu-dong Mapo-gu, Seoul 121-791 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22420598
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 58; Conference: IFFM2013: International forum on functional materials, Jeju City (Korea, Republic of), 27-29 Jun 2013; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ATOMIZATION; CALORIMETRY; COPPER; ELASTICITY; INTERMETALLIC COMPOUNDS; NICKEL; PHASE TRANSFORMATIONS; POROUS MATERIALS; POWDER METALLURGY; POWDERS; SHAPE MEMORY EFFECT; SINTERING; STRAINS; TITANIUM; X-RAY DIFFRACTION