scholarly journals Ti-15Mo alloy prepared by cryogenic milling and spark plasma sintering

2020 ◽  
Vol 321 ◽  
pp. 12029
Author(s):  
A. Terynková ◽  
J. Kozlík ◽  
K. Bartha ◽  
T. Chráska ◽  
J. Stráský
Keyword(s):  
Spark Plasma Sintering ◽  
Milled Powder ◽  
Fine Grained ◽  
Cryogenic Milling ◽  
Ω Phase ◽  
Α Phase ◽  
Plasma Sintering ◽  
Refined Microstructure ◽  
Spark Plasma ◽  
Lower Temperature

In this study, Ti-15Mo alloy powder was prepared by gas atomization and subsequent cryogenic milling in order to achieve ultra-fine grained microstructure. Both milled and non-milled powders were compacted by spark plasma sintering (SPS) at temperature of 800 °C for different sintering times up to 6 minutes. Sintering temperature and time affect porosity, microstructure and phase composition of the alloy. Milled powder can be sintered at comparatively lower temperature to achieve fully dense material. Sintering below β-transus temperature results in α+β-structure. Furthermore, amount of α-phase is higher in the material sintered from the milled powder due to increased oxygen content and also due to refined microstructure which facilitates α-phase precipitation. Mechanical properties are also affected by formation of ω-phase during uncontrolled cooling in the SPS machine.

scholarly journals Mechanical Properties of Ti-15Mo Alloy Prepared by Cryogenic Milling and Spark Plasma Sintering

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1280 ◽  
Author(s):  
Anna Veverková ◽  
Jiří Kozlík ◽  
Kristína Bartha ◽  
Tomáš Chráska ◽  
Cinthia Antunes Corrêa ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Spark Plasma Sintering ◽  
Milled Powder ◽  
Two Phase ◽  
High Oxygen Content ◽  
Cryogenic Milling ◽  
Plasma Sintering ◽  
Refined Microstructure ◽  
Spark Plasma ◽  
Powder Particles

Metastable β-Ti alloy Ti-15Mo was prepared by cryogenic ball milling in a slurry of liquid argon. Material remained ductile even at low temperatures, which suppressed particle refinement, but promoted intensive plastic deformation of individual powder particles. Repetitive deformation of powder particles is similar to the multidirectional rolling and resembles bulk severe plastic deformation (SPD) methods. Initial and milled powders were compacted by spark plasma sintering. Sintered milled powder exhibited a refined microstructure with small β-grains and submicrometer sized α-phase precipitates. The microhardness and the yield tensile strength of the milled powder after sintering at 850 °C attained 350 HV and 1200 MPa, respectively. Low ductility of the material can be attributed to high oxygen content originating from the cryogenic milling. This pioneering work shows that cryogenic milling followed by spark plasma sintering is able to produce two-phase β-Ti alloys with refined microstructure and very high strength levels.

Manufacturing of fine-grained titanium by cryogenic milling and spark plasma sintering

2020 ◽  
Vol 772 ◽  
pp. 138783 ◽  
Author(s):  
Jiří Kozlík ◽  
Hanka Becker ◽  
Josef Stráský ◽  
Petr Harcuba ◽  
Miloš Janeček
Keyword(s):  
Spark Plasma Sintering ◽  
Fine Grained ◽  
Cryogenic Milling ◽  
Plasma Sintering ◽  
Spark Plasma

scholarly journals Effect of High Pressure Spark Plasma Sintering on the Densification of a Nb-Doped TiO2 Nanopowder

Ceramics ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 507-520
Author(s):  
Alexandre Verchère ◽  
Sandrine Cottrino ◽  
Gilbert Fantozzi ◽  
Shashank Mishra ◽  
Thomas Gaudisson ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Applied Pressure ◽  
Sintering Process ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Lower Temperature

Sintering under pressure by means of the spark plasma sintering (SPS) technique is a common route to reduce the sintering temperature and to achieve ceramics with a fine-grained microstructure. In this work, high-density bulk TiO2 was sintered by high pressure SPS. It is shown that by applying high pressure during the SPS process (76 to 400 MPa), densification and phase transition start at lower temperature and are accelerated. Thus, it is possible to dissociate the two densification steps (anatase then rutile) and the transition phase during the sintering cycle. Regardless of the applied pressure, grain growth occurs during the final stage of the sintering process. However, twinning of the grains induced by the phase transition is enhanced under high pressure resulting in a reduction in the crystallite size.

scholarly journals Microstructure and texture in cryomilled and spark plasma sintered Ti Grade 2

2020 ◽  
Vol 321 ◽  
pp. 12030
Author(s):  
Jiří Kozlík ◽  
Josef Stráský ◽  
Petr Harcuba ◽  
Tomáš Chráska ◽  
Miloš Janeček
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Milled Powder ◽  
Recrystallization Process ◽  
Advanced Technique ◽  
Microstructural Investigation ◽  
Cryogenic Milling ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Powder Particles

Titanium (Grade 2) was processed by cryogenic milling and subsequently sintered by spark plasma sintering (SPS) method with the aim of creating and preserving the ultra-fine grained (UFG, < 1 μm) microstructure. Microstructural investigation was performed after both cryogenic milling and spark plasma sintering. An advanced technique of transmission Kikuchi diffraction (TKD) was used to characterize the individual milled powder particles. Investigations of milled powders showed significant grain refinement down to 50 nm after milling in liquid argon with tungsten carbide balls. We assume that this is the equilibrium grain size resulting from the balance of deformation, recovery and dynamic recrystallization. A texture, resembling the rolling texture in Ti, was also found in the milled particles, which can be explained by the nature of deformation during milling. UFG microstructure was not maintained after sintering, with the mean grain size of 2.6 μm. Although the grains are completely recrystallized, a texture, similar to the powder texture, was also found in these samples as a result of packing of the powder particles and the nature of the recrystallization process (continuous static recrystallization).

Preparation of Fine-Grained CeO2–SiC Ceramics for Inert Fuel Matrices by Spark Plasma Sintering

2020 ◽  
Vol 56 (12) ◽  
pp. 1307-1313
Author(s):  
L. S. Alekseeva ◽  
A. V. Nokhrin ◽  
M. S. Boldin ◽  
E. A. Lantsev ◽  
A. I. Orlova ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Fine Grained ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

Ultra-Fine Grained Ti-15Mo Alloy Prepared by Powder Metallurgy

2018 ◽  
Vol 941 ◽  
pp. 1276-1281
Author(s):  
Anna Terynková ◽  
Jiří Kozlík ◽  
Kristína Bartha ◽  
Tomáš Chráska ◽  
Josef Stráský
Keyword(s):  
Powder Metallurgy ◽  
Bulk Material ◽  
Alpha Phase ◽  
Full Density ◽  
Fine Grained ◽  
Cryogenic Milling ◽  
Aircraft Manufacturing ◽  
Plasma Sintering ◽  
Beta Matrix ◽  
Spark Plasma

Ti-15Mo alloy belongs to metastable β-Ti alloys that are currently used in aircraft manufacturing and Ti15Mo alloy is a perspective candidate for the use in medicine thanks to its biotolerant composition. In this study, Ti15Mo alloy was prepared by advanced techniques of powder metallurgy. The powder of gas atomized Ti-15Mo alloy was subjected to cryogenic milling to achieve ultra-fine grained microstructure within the powder particles. Powder was subsequently compacted using spark plasma sintering (SPS). The effect of cryogenic milling on the microstructure and phase composition of final bulk material after SPS was studied by scanning electron microscopy. Sintering at 750°C was not sufficient for achieving full density in gas atomized powder, while milled material could be successfully sintered at this temperature. Alpha phase particles precipitated during sintering and their size, as well as the size of beta matrix grains, was strongly affected by the sintering temperature.

scholarly journals Superplasticity of fine-grained alumina obtained by spark plasma sintering

2021 ◽  
Vol 1758 (1) ◽  
pp. 012031
Author(s):  
A A Popov ◽  
V N Chuvil’deev ◽  
M S Boldin ◽  
A V Nokhrin ◽  
E A Lantsev ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma

Microstructure of Cu-TiB2 Nanocomposite during Spark Plasma Sintering

2004 ◽  
Vol 449-452 ◽  
pp. 1113-1116 ◽  
Author(s):  
Young Soon Kwon ◽  
Ji Soon Kim ◽  
Jong Jae Park ◽  
Hwan Tae Kim ◽  
Dina V. Dudina
Keyword(s):  
Spark Plasma Sintering ◽  
Titanium Diboride ◽  
Copper Matrix ◽  
Microstructural Change ◽  
Simultaneous Action ◽  
Fine Grained ◽  
Pulse Electric Current ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Pulse Electric

Microstructural change of TiB2-Cu nanocomposite during spark plasma sintering (SPS) was investigated. Under simultaneous action of pressure, temperature and pulse electric current titanium diboride nanoparticles distributed in copper matrix move, agglomerate and form a interpenetrating phase composite with a fine-grained skeleton. Increase of SPS temperatures and holding times promotes the densification of sintered compacts due to local melting of copper matrix.

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