Fabrication of TiNi Shape Memory Alloy by Powder Metallurgy

Funami, Kunio; Sekiguchi, Yukio; Funakubo, Hiroyasu

doi:10.2320/jinstmet1952.48.11_1113

Cited by 12 publications

(3 citation statements)

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“…Furthermore, porous NiTi alloy has excellent mechanical properties, good corrosion resistance and biocompatibility, along with shape memory effect. 1 There are many reports [2][3][4][5][6][7] about the preparation of NiTi alloy by powder metallurgy, however most of these studies focus on the homogeneous compact NiTi alloy but not on the medical porous one. The lack of comprehensive reports on the porous NiTi alloy produced from EPS is the main motivation of this paper.…”

Section: Introductionmentioning

confidence: 99%

Porous NiTi alloy prepared from elemental powder sintering

Rong

1998

J. Mater. Res.

109

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An elemental powder sintering (EPS) technique has been developed for the synthesis of porous NiTi alloy, in which Ni and Ti powders are used as the reactants and TiH2 powder is added as a pore-forming agent and active agent. Effects of various experimental parameters (sintering temperature, sintering time, and TiH2 content) on the porosity, pore size, and pore distribution as well as phase composition in experimental alloys are investigated. It is found that in order to avoid the formation of carcinogenic pure Ni phase, the porous NiTi alloy should be synthesized over a temperature of 1223 K. This gives NiTi as the main phase without any elemental phase. Substitution of Ti by TiH2 is more economic and more favorable to obtain homogeneous porous NiTi alloy. A proper selection of initial powders, ball-milling, pressing, and sintering process makes it possible to achieve the porous NiTi alloy with desired properties.

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Section: Introductionmentioning

confidence: 99%

Porous NiTi alloy prepared from elemental powder sintering

Rong

1998

J. Mater. Res.

109

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“…It was found that the amount of hydrogen that was fixed at these barriers increases as the Mo 2 C increases by measuring the amount of hydrogen at a constantly increasing temperature. 9) These results suggest that the reacted TiC particles and Ti hydrides are more important factors in arresting grain growth, as found in Figs. 2 and 4.…”

Section: Influence Of the Hydrogenation Treatment On Grain Refinementmentioning

confidence: 52%

Effect of Hydrogenation Treatment on Grain Refinement of Reaction Sintered Ti-6Al-4V Alloy Composites

et al. 2004

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The current study was conducted to develop a Ti-6Al-4V alloy composite material with a fine structure with improved mechanical properties by precipitating TiC particles via reaction-sintering and, additionally, by incorporating the effects of hydrides formed by hydrogenation treatment, using powder to which Mo 2 C had been added. The effects of precipitated TiC particles, and the subsequent generation of hydrides by hydrogenation treatment, heavy-strain working, and recrystallization treatment on grain refinement during the forming process were studied by means of structural observations. Warm rolling and multi-axial alternate forging (MAF) were employed as the heavy-strain working methods. The base metal structure of the Ti-6Al-4V composite material prepared by hydrogenation treatment on the sintered body prepared by spark plasma sintering (SPS) contains particles with a grain size not greater than 1 mm, which become finer with increasing hydrogen content. The particle size of TiC formed by reaction sintering, however, is not changed by heavy-strain working after hydrogenation. Its room temperature tensile strength increases with the amount of TiC precipitation, and is higher than that of non-hydrogenated material.

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“…7. All the added TiO 2 particles were decomposed and disappear, SPSed TiNi alloy using pre-mixed Ti-Ni-TiO 2 particles became hybrid organization TiNi phase, Ti [12][13][14] . On the other hand, the end plateau region corresponding in strain decreased with the increase in the additions of the amount of TiO 2 particles.…”

Section: Microstructures and Mechanical Properties Of Pmmentioning

confidence: 99%

Microstructures and Mechanical Properties of Shape Memory Alloy Using Pre-Mixed TiNi Powders with TiO<sub>2</sub> Particles

et al. 2018

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In this study, microstructural and mechanical properties of the extruded and heat-treated TiNi alloys by sintering the mixture of TiNi pre-mixed powder with titanium dioxide (TiO 2) particles were investigated. Pure Ti and pure Ni powder with TiO 2 particles were mixed and consolidated by spark plasma sintering (SPS). SPSed TiNi alloy compacts were extruded and heat-treated subsequently. SPSed TiNi alloy compacts had TiNi matrix and Ti 4 Ni 2 O phase. Ti 4 Ni 2 O phase was formed during SPS by reaction between TiNi matrix and oxygen atoms originated from additive TiO 2 particles. Consequently, the heat-treated Ti-50.5 at%Ni alloy using pre-mixed powder with 1.0 vol% TiO 2 particles showed a high plateau stress of 630 MPa and a good shape recovery of 79.7% in 8% strain applied. The heat-treated TiNi alloy with 1.0 vol% TiO 2 particles revealed the high strength and good shape memory properties. The high strengthening mechanism of the TiNi alloy using pre-mixed powder with TiO 2 particles was mainly due to a decrease martensitic transformation temperature by an increase solute Ni content in TiNi matrix after reaction between TiNi and TiO 2 .

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Fabrication of TiNi Shape Memory Alloy by Powder Metallurgy

Cited by 12 publications

References 0 publications

Porous NiTi alloy prepared from elemental powder sintering

Porous NiTi alloy prepared from elemental powder sintering

Effect of Hydrogenation Treatment on Grain Refinement of Reaction Sintered Ti-6Al-4V Alloy Composites

Microstructures and Mechanical Properties of Shape Memory Alloy Using Pre-Mixed TiNi Powders with TiO<sub>2</sub> Particles

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