Martensitic transformation behaviors of rapidly solidified Ti–Ni–Mo powders
- Department of Advanced Materials, Keimyung University, 1000 Shindang-dong, Dalseo-gu, Daegu 704-701 (Korea, Republic of)
For the fabrication of bulk near-net-shape shape memory alloys and porous metallic biomaterials, consolidation of Ti–Ni–Mo alloy powders is more useful than that of elemental powders of Ti, Ni and Mo. Ti{sub 50}Ni{sub 49.9}Mo{sub 0.1} shape memory alloy powders were prepared by gas atomization, and transformation temperatures and microstructures of those powders were investigated as a function of powder size. XRD analysis showed that the B2–R–B19 martensitic transformation occurred in powders smaller than 150 μm. According to DSC analysis of the as-atomized powders, the B2–R transformation temperature (T{sub R}) of the 25–50 μm powders was 18.4 °C. The T{sub R} decreased with increasing powder size, however, the difference in T{sub R} between 25–50 μm powders and 100–150 μm powders is only 1 °C. Evaluation of powder microstructures was based on SEM examination of the surface and the polished and etched powder cross sections and the typical images of the rapidly solidified powders showed cellular morphology. Porous cylindrical foams of 10 mm diameter and 1.5 mm length were fabricated by spark plasma sintering (SPS) at 800 °C and 5 MPa. Finally these porous TiNi alloy samples are heat-treated for 1 h at 850 °C, and then quenched in ice water. The bulk samples have 23% porosity and 4.6 g/cm{sup 3} density and their T{sub R} is 17.8 °C.
- OSTI ID:
- 22215526
- Journal Information:
- Materials Research Bulletin, Vol. 47, Issue 10; Conference: IFFM2011: 2011 international forum on functional materials, Jeju Island (Korea, Republic of), 28-31 Jul 2011, AFM-2: 2. special symposium on advances in functional materials, Jeju Island (Korea, Republic of), 28-31 Jul 2011; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microstructure and martensitic transformation in Si-coated TiNi powders prepared by ball milling
Damping characteristics of Ti{sub 50}Ni{sub 49.5}Fe{sub 0.5} and Ti{sub 50}Ni{sub 40}Cu{sub 10} ternary shape memory alloys