scholarly journals Development of Ti PVD Films to Limit the Carburization of Metal Powders during SPS Process

Solids ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 395-406
Author(s):  
Maria-Rosa Ardigo-Besnard ◽  
Aurélien Besnard ◽  
Mathias Moser ◽  
Florian Bussière
Keyword(s):  
Thermal Contact ◽  
Carbon Diffusion ◽  
Uniaxial Pressure ◽  
Metal Powders ◽  
Fine Grained ◽  
Pvd Coating ◽  
Plasma Sintering ◽  
Iron Diffusion ◽  
Spark Plasma ◽  
Pvd Film

Spark plasma sintering technique is used for the fabrication of dense materials with a fine-grained microstructure. In this process, a powder is placed into a graphite mold and a uniaxial pressure is applied by two graphite punches. A graphite foil is inserted between the punches and the powder and between the mold and the powder to ensure good electrical, physical and thermal contact. One of the major drawbacks during sintering of metal powders is the carburization of the powder in contact with the graphite foils. In this study, a PVD coating of titanium was applied on the graphite foils in contact with the metal powder (pure iron). The results are promising, as the investigations show that the application of a Ti PVD film of 1.5 and 1.1 µm thickness is effective to completely avoid the carburization of iron powder. Carbon diffuses inside the PVD film during sintering. In parallel, iron diffusion was revealed inside the Ti coating of 1.5 µm thickness. On the other hand, a Ti PVD film of 0.5 µm thickness provides a protection against carbon diffusion just on the sides in contact with the mold, proving that the coating thickness represents an important parameter to consider.

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

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).

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.

The Effect of Preliminary Mechanical Activation on the Structure and Mechanical Properties of Ni3Al+B Material Obtained by SPS

2017 ◽  
Vol 743 ◽  
pp. 19-24 ◽  
Author(s):  
Lilia I. Shevtsova ◽  
Anatoliy A. Bataev ◽  
Vyacheslav I. Mali ◽  
Maksim A. Esikov ◽  
Veronika V. Sun Shin Yan ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Bending Strength ◽  
Stoichiometric Composition ◽  
Initial Mixture ◽  
Optical Microscope ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Fine Grained Structure ◽  
Spark Plasma ◽  
Almost All

In the present study, a mixture of powders (87.9 at.% Ni, 12 at.% Al, 0.1 at.% B) was used as the initial material to produce sintered Ni3Al + B alloy. Spark Plasma Sintering (SPS) method was used to compact the powder. The powder mixtures were previously prepared in two ways: mixing the initial powders in a mortar (М1) and mechanical activation (М2). The microstructure was observed using optical microscope (OM). The addition of small amount of boron to the initial mixture of nickel and aluminum improves the density of the sintered Ni3Al intermetallic compound (98.8%). The results of density, bending and microhardness tests showed, that the provisional three-minute mechanical activation improves almost all properties of the sintered material. The compact obtained by SPS by M2 contributes to the formation of a homogeneous fine-grained structure of the material. It leads to further increase in flexural bending strength up to 2200 MPa. This value is almost 8 times the strength of the intermetallic Ni3Al stoichiometric composition obtained by SPS.

Preparation and Magnetic Properties of Dense NiCuZn Ferrite by Spark Plasma Sintering

2008 ◽  
Vol 368-372 ◽  
pp. 601-603
Author(s):  
Xi Wei Qi ◽  
Ji Zhou ◽  
Zhen Xing Yue ◽  
Ming Ya Li ◽  
Xiu Mei Han
Keyword(s):  
Spark Plasma Sintering ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Impurity Phase ◽  
Uniaxial Pressure ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Conventional Sintering ◽  
Spark Plasma ◽  
Nicuzn Ferrite

Dense NiCuZn ferrites consisting of fine grains were prepared by spark plasma sintering (SPS) at 750°C for 3 min under a uniaxial pressure of 15 MPa. The powders were densified to >95% of theoretical density by the SPS process, and the average grain size of the prepared NiCuZn ferrite was < 1 /m. The saturation magnetization of prepared specimens (without further annealing treatment) was approximate 50.54 emu/g, which was slightly smaller than that of 52.21 emu/g for specimens prepared by conventional sintering at 980°C for 4 h. Phase identifications indicated that prepared NiCuZn ferrite existed impurity phase (Cu2O), and Cu2O would gradually transform to CuO when annealing temperature increased.

Sign in / Sign up

Export Citation Format

Share Document