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.

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 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.

Improving Mechanical Properties of Co-Cr-W Alloys by Powder Metallurgy

2017 ◽  
Vol 890 ◽  
pp. 348-351
Author(s):  
Choncharoen Sawangrat ◽  
Komgrit Leksakul
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Total Elongation ◽  
Structure Design ◽  
Coarse Grained ◽  
Harmonic Structure ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Commercial Applications

This study focuses on improving the mechanical properties of Co-Cr-W alloys by applying Harmonic Structure Design – bimodal grain size distribution with an interconnected framework of ultra-fine-grained (UFG) regions, called the “shell region”, surrounding isolated coarse-grained (CG) regions. Harmonic structure Co-Cr specimens were successfully fabricated by Powder Metallurgy (PM) that consisted of controlled mechanical milling and spark plasma sintering. The sintered compacts revealed an outstanding combination of strength and total elongation. Moreover, the sintering dwell time significantly improved densification and led to large total elongation. PM improved the mechanical properties of Co-Cr-W alloys and offered an attractive approach to fabricate harmonic structures for commercial applications.

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

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

scholarly journals A Study of the Impact of Graphite on the Kinetics of SPS in Nano- and Submicron WC-10%Co Powder Compositions

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 331-363
Author(s):  
Eugeniy Lantcev ◽  
Aleksey Nokhrin ◽  
Nataliya Malekhonova ◽  
Maksim Boldin ◽  
Vladimir Chuvil'deev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Continuous Heating ◽  
Diffusion Creep ◽  
Hard Alloys ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact ◽  
Kinetics Of

This study investigates the impact of carbon on the kinetics of the spark plasma sintering (SPS) of nano- and submicron powders WC-10wt.%Co. Carbon, in the form of graphite, was introduced into powders by mixing. The activation energy of solid-phase sintering was determined for the conditions of isothermal and continuous heating. It has been demonstrated that increasing the carbon content leads to a decrease in the fraction of η-phase particles and a shift of the shrinkage curve towards lower heating temperatures. It has been established that increasing the graphite content in nano- and submicron powders has no significant effect on the SPS activation energy for “mid-range” heating temperatures, QS(I). The value of QS(I) is close to the activation energy of grain-boundary diffusion in cobalt. It has been demonstrated that increasing the content of graphite leads to a significant decrease in the SPS activation energy, QS(II), for “higher-range” heating temperatures due to lower concentration of tungsten atoms in cobalt-based γ-phase. It has been established that the sintering kinetics of fine-grained WC-Co hard alloys is limited by the intensity of diffusion creep of cobalt (Coble creep).

Effect of Spark Plasma Sintering on the Microstructure Evolution and Properties of M3:2 High-Speed Steel

2014 ◽  
Vol 788 ◽  
pp. 329-333
Author(s):  
Rui Zhou ◽  
Xiao Gang Diao ◽  
Jun Chen ◽  
Xiao Nan Du ◽  
Guo Ding Yuan ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Spark Plasma Sintering ◽  
High Speed ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Speed Steel ◽  
Continuous Heating ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact

Effects of sintering temperatures on the microstructure and mechanical performance of SPS M3:2 high speed steel prepared by spark plasma sintering was studied. High speed steel sintering curve of continuous heating from ambient temperature to 1200°C was estimated to analyze the sintering processes and sintering temperature range. The sintering temperature within this range was divided into groups to investigate hardness, relative density and microstructure of M3:2 high-speed steel. Strip and quadrate carbides were observed inside the equiaxed grains. SPS sintering temperature at 900°C can lead to nearly full densification with grain size smaller than 20μm. The hardness and bending strength are higher than that of the conventionally powder metallurgy fabricated ones sintered at 1270°C. However, fracture toughness of the high speed steel is lower than that of the conventional powder metallurgy steels. This can be attributed to the shape and distribution of M6C carbides which reduce the impact toughness of high speed steels.

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.

Dielectric properties of fine-grained BaTiO3 prepared by spark-plasma-sintering

2004 ◽  
Vol 83 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Baorang Li ◽  
Xiaohui Wang ◽  
Longtu Li ◽  
Hui Zhou ◽  
Xingtao Liu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Spark Plasma Sintering ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma

scholarly journals Mechanical Milling-Assisted Spark Plasma Sintering of Fine-Grained W-Ni-Mn Alloy

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1323 ◽  
Author(s):  
Yanlin Pan ◽  
Daoping Xiang ◽  
Ning Wang ◽  
Hui Li ◽  
Zhishuai Fan
Keyword(s):  
Spark Plasma Sintering ◽  
Mechanical Milling ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Interface Fracture ◽  
Composite Powders ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Binding Phase ◽  
Spark Plasma

Fine-grained W-6Ni-4Mn alloys were fabricated by spark plasma sintering (SPS) using mechanical milling W, Ni and Mn composite powders. The relative density of W-6Ni-4Mn alloy increases from 71.56% to 99.60% when it is sintered at a low temperature range of 1000–1200 °C for 3 min. The spark plasma sintering process of the alloy can be divided into three stages, which clarify the densification process of powder compacts. As the sintering temperature increases, the average W grain size increases but remains at less than 7 µm and the distribution of the binding phase is uniform. Transmission electron microscopy (TEM) observation reveals that the W-6Ni-4Mn alloy consists of the tungsten phase and the γ-(Ni, Mn, W) binding phase. As the sintering temperature increases, the Rockwell hardness and bending strength of alloys initially increases and then decreases. The optimum comprehensive hardness and bending strength of the alloy are obtained at 1150 °C. The main fracture mode of the alloys is W/W interface fracture.

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