Published January 2021 | Version v1
Journal article Metadata-only

Local formation of Ni4Ti3 in non-equilibrium state and its influence on the transformation temperature of Ti-rich NiTi alloys

Creators

  • 1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China)
  • 2. The Second XiangYa hospital, Central South University, Changsha, 410083 (China)
  • 3. Research centre for materials science and engineering, Guangxi University of Science and Technology, Liuzhou, 545006 (China)
  • 4. School of Materials Science and Engineering, Xiangtan University, Xiangtan, 411105 (China)
  • 5. State Key Laboratory of Cardiovascular Disease, Center of Vascular Surgery, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037 (China)

Description

Highlights:• Ni4Ti3 phase was observed in Ti-riched NiTi alloys fabricated by MIM.• Carbon and oxygen impurities are the main reason for irregular precipitation.• Accelerated diffusion accounts for no precipitation in elemental NiTi alloys.• Transition temperature increases with loss of Ti due to non-balanced precipitation. -- Abstract: Local Ni4Ti3 precipitation in non-equilibrium state was observed in Ti-riched Ni49.4Ti50.6 alloys, prepared by metal injection molding (MIM) without any solution or aging treatment. Upon investigating the underlying mechanism, the precipitation was found to have been caused by C and O impurities, which led to the formation of a Ni-riched region, which acted as a precursor for the precipitation of Ni4Ti3. The absence of liquid phase during pre-alloyed powder sintering was another reason for this phenomenon. The transformation temperature associated with the non-balanced formation of precipitation was discussed.

Additional details

Identifiers

DOI
10.1016/j.jallcom.2020.157065;
PII
S0925838820334290;

Publishing Information

Journal Title
Journal of Alloys and Compounds
Journal Volume
852
Journal Page Range
vp.
ISSN
0925-8388
CODEN
JALCEU

INIS

Country of Publication
Switzerland
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
55032049
Subject category
S36: MATERIALS SCIENCE;
Descriptors DEI
MARTENSITIC STEELS; NICKELATES; PHASE TRANSFORMATIONS; PRECIPITATION; SHAPE MEMORY EFFECT; TITANIDES; TRANSITION TEMPERATURE
Descriptors DEC
ALLOYS; CARBON ADDITIONS; IRON ALLOYS; IRON BASE ALLOYS; NICKEL COMPOUNDS; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SEPARATION PROCESSES; STEELS; THERMODYNAMIC PROPERTIES; TITANIUM COMPOUNDS; TRANSITION ELEMENT ALLOYS; TRANSITION ELEMENT COMPOUNDS

Optional Information

Copyright
Copyright (c) 2020 Elsevier B.V. All rights reserved.