Fabrication, microstructure and mechanical properties of W-NiTi composites

Journal Article · Fri Nov 04 00:00:00 EDT 2016 · Journal of Alloys and Compounds

DOI:https://doi.org/10.1016/j.jallcom.2016.11.032· OSTI ID:1755923

Shao, Yang ^[1]; Guo, Fangmin ^[1]; Huan, Yong ^[2]; Jiang, Daqiang ^[1]; Zhang, Junsong ^[1]; Ren, Yang ^[3]; Cui, Lishan ^[1]

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1. China Univ. of Petroleum, Beijing (China). State Key Lab. of Heavy Oil Processing
2. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Mechanics, State Key Lab. of Nonlinear Mechanics
3. Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division

Here, new two-phase tungsten-based composites containing 88 wt% tungsten powders and 12 wt% nearly equiatomic NiTi alloy deforming by martensite variant detwinning were fabricated by infiltration and hot pressing in this study. The change of Ti/Ni ratio in NiTi mater alloy and the effect of addition of Nb element on the microstructure, martensitic transformation and mechanical properties of W-NiTi composites were investigated by comparison of W-Ni₅₀Ti₅₀, W-Ni₄₄Ti₅₆, W-Ni₄₂Ti₅₈ and W-Ni₄₂Ti₅₃Nb₅ composites. The results showed that brittle Ni₃Ti formed in the W-Ni₅₀Ti₅₀ and W-Ni₄₄Ti₅₆ composites and brittle Ti₂Ni formed in the W-Ni₄₂Ti₅₈ composites while no brittle intermetallics formed in the W-Ni₄₂Ti₅₃Nb₅ composite. The W-Ni₄₂Ti₅₃Nb₅ composite exhibited the sharpest martensitic transformation with the largest transformation enthalpy among the four different composites. The W-Ni₄₂Ti₅₃Nb₅ composite exhibited a double-yielding phenomenon under compression with an ultimate compressive strength of 3820 MPa and a deformation of 50.4%. In-situ synchrotron high-energy Xray diffraction measurements revealed the first yielding was caused by the martensite reorientation of the NiTi matrix and the second was due to the commencement of massive plastic deformation of the reoriented martensite and is also attributed to the microscopic internal fracturing of the W particles.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; National Natural Science Foundation of China (NNSFC); National 973 Program of China
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1755923
• Journal Information: Journal of Alloys and Compounds, Journal Name: Journal of Alloys and Compounds Vol. 695; ISSN 0925-8388
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
infiltration
martensite variant detwinning
near equiatomic NiTi
tungsten