Processing and Excellent Oxidation Resistance of Nanocrystalline Fe-Cr Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 1122-1125
Author(s):  
Rajeev K. Gupta ◽  
B.V. Mahesh ◽  
R.K. Singh Raman ◽  
Carl C. Koch
Keyword(s):  
Oxidation Resistance ◽  
Secondary Ion Mass Spectrometry ◽  
Nanocrystalline Alloy ◽  
High Energy ◽  
Processing Route ◽  
Protective Oxide ◽  
Time Intervals ◽  
Regular Time ◽  
Order Of Magnitude ◽  
Energy Ball

Nanocrystalline and microcrystalline Fe-10Cr alloys were prepared by high energy ball milling followed by compaction and sintering, and then oxidized in air for 52 hours at 400°C. The oxidation resistance of nanocrystalline Fe-10Cr alloy as determined by measuring the weight gain after regular time intervals was compared with that of the microcrystalline alloy of same chemical composition (also prepared by the same processing route and oxidized under identical conditions). Oxidation resistance of nanocrystalline Fe10Cr alloy was found to be in excess of an order of magnitude superior than that of microcrystalline Fe10Cr alloy. The paper also presents results of secondary ion mass spectrometry of oxidized samples of nanocrystalline and microcrystalline Fe-Cr alloys, evidencing the formation of a more protective oxide scale in the nanocrystalline alloy.

Microstructure and Oxidation Resistance of Mechanically Alloyed and Sintered Ni-Nb and Ni-Nb-Ta Alloys

2017 ◽  
Vol 899 ◽  
pp. 19-24
Author(s):  
Lucas Moreira Ferreira ◽  
Stephania Capellari Rezende ◽  
Antonio Augusto Araújo Pinto da Silva ◽  
Gael Yves Poirier ◽  
Gilberto Carvalho Coelho ◽  
...  
Keyword(s):  
Ball Milling ◽  
Oxidation Resistance ◽  
Energy Dispersive Spectrometry ◽  
High Energy ◽  
Milling Process ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Static Oxidation ◽  
Energy Ball

The present work reports on the microstructure and oxidation resistance of Ni-25Nb, Ni-20Nb-5Ta and Ni-15Nb-10Ta alloys produced by high-energy ball milling and subsequent sintering. The sintered samples were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry, and static oxidation tests. Homogeneous microstructures of the binary and ternary alloys indicated the major presence of the β-Ni3Nb compound as matrix, which dissolved large amounts of tantalum. Consequently, the β-Ni3Nb peaks moved toward the direction of smaller diffraction angles. Iron contamination lower than 6.7 at.-% was detected by EDS analysis, which were picked-up during the previous ball milling process. After the static oxidation tests (1100°C for 4 h) the sintered Ni-25Nb, Ni-20Nb-5Ta and Ni-15Nb-10Ta alloys presented mass gains of 31.5%, 30.5% and 28.8%, respectively. Despite the higher densification of the Ni-15Nb-10Ta alloy, the results suggested that the tantalum addition contributed to improve the oxidation resistance of the β-Ni3Nb compound.

scholarly journals Innovative processing routes in manufacturing of metal matrix composite materials

10.30544/629 ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 1-13
Author(s):  
Jovana Ruzic ◽  
Marko Simić ◽  
Nikolay Stoimenov ◽  
Dušan Božić ◽  
Jelena Stašić
Keyword(s):  
Ball Milling ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Cost Effective ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Processing Route ◽  
Ingot Metallurgy ◽  
Energy Ball ◽  
Manufacturing Techniques

Metal matrix composites (MMCs) belong to a group of modern materials owing to their excellent technological, mechanical, and physical properties such as excellent wear and corrosion resistance, high electrical and thermal conductivity, improved strength and hardness. Final properties of MMCs are affected equally by all steps of its manufacturing process. It is shown that by using adequate process parameters to obtain starting materials (reaching the specific size, shape, and reactivity) the control of volume fraction and distribution of reinforcements within the matrix can be achieved. For this purpose, mechanical alloying has been appointed as a good approach. MMCs can be produced using powder metallurgy, ingot metallurgy, and additive manufacturing techniques. Combining high-energy ball milling with these techniques enables the design of an innovative processing route for MMCs manufacturing. Mechanochemical process (achieved using high-energy ball milling) was employed in three manufacturing procedures: hot pressing, compocasting, and laser melting/sintering for obtaining of the suitable powder. These production routes for MMCs manufacturing were the subject of this work. The aim of MMCs design is to establish an optimal combination of production techniques merged into the cost-effective fabrication route for obtaining MMCs with required properties.

scholarly journals Manufacturing of Conductive, Wear-Resistant Nanoreinforced Cu-Ti Alloys Using Partially Oxidized Electrolytic Copper Powder

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1261
Author(s):  
Stepan Vorotilo ◽  
Pavel Alexandrovich Loginov ◽  
Alexandr Yuryevich Churyumov ◽  
Alexey Sergeevich Prosviryakov ◽  
Marina Yakovlevna Bychkova ◽  
...  
Keyword(s):  
Ball Milling ◽  
Copper Matrix ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Single Stage ◽  
Two Stage ◽  
Ti Alloys ◽  
Order Of Magnitude ◽  
Energy Ball ◽  
Reactive Powder

Reactive powder composites Cu-(0–15%)TiH2 containing up to 5% native Cu2O were manufactured by high energy ball milling and then hot-pressed to produce bulk nanostructured copper–matrix alloys reinforced by Cu3Ti3O inclusions. Two high-energy ball-milling (HEBM) protocols were employed for the fabrication of Cu-Ti alloys: single-stage and two-stage ball milling, resulting in an order of magnitude refinement of TiH2 particles in the reactive mixtures. Single-stage HEBM processing led to the partial retention of Ti in the microstructure of hot-pressed specimens as the α-Ti phase and formation of fine-grained (100–200 nm) copper matrix interspersed with 5–20 nm Cu3Ti3O precipitates, whereas the two-stage HEBM led to the complete conversion of TiH2 into the Cu3Ti3O phase during the hot pressing but produced a coarser copper matrix (1–2 μm) with 0.1–0.2 μm wide polycrystalline Cu3Ti3O layers on the boundaries of Cu grains. The alloy produced using single-stage HEBM was characterized by the highest strength (up to 950 MPa) and electrical conductivity (2.6 × 107 Sm/m) as well as the lowest specific wear rate (1.1 × 10−5 mm3/N/m). The tribological performance of the alloy was enhanced by the formation of Cu3Ti3O microfibers in the wear debris, which reduced the friction coefficient against the Al2O3 counter-body. The potential applications of the developed alloys are briefly discussed.

Effects of Ball Mill Additives on Properties of Bronze Powder

2011 ◽  
Vol 71-78 ◽  
pp. 3539-3542
Author(s):  
Yu Dong Jiang ◽  
Xiao Lan Cai ◽  
Kai Jun Wang
Keyword(s):  
Oxidation Resistance ◽  
Ball Mill ◽  
Marked Effect ◽  
Great Influence ◽  
High Energy ◽  
Bronze Powder ◽  
High Energy Ball Mill ◽  
Method Effects ◽  
Energy Ball ◽  
Surface Covering

Bronze powders were prepared using high-energy ball mill method. Effects of different additives on particle size and its distribution, gloss, water coverage and oxidation resistance of powders were discussed. The results shows that aluminum stearate has a great impact to sheet formation of bronze powder. Hexadecanoic acid has a great influence on the gloss and water surface covering. Polyvinyl alcohol(PVA) has a marked effect to improve oxidation resistance of the bronze powders.

Oxidation Resistance Behave of Stainless Steel /TiC Nano Powders

2010 ◽  
Vol 434-435 ◽  
pp. 109-112
Author(s):  
Wen Yi Chen ◽  
Jian Zhou ◽  
Ying Liu
Keyword(s):  
Stainless Steel ◽  
Ball Milling ◽  
Oxidation Resistance ◽  
Oxidation Reaction ◽  
Raw Materials ◽  
Steel Powder ◽  
High Energy ◽  
Nanocomposite Powder ◽  
Milling Method ◽  
Energy Ball

Stainless steel/TiC nanocomposite powder were prepared by high-energy ball-milling method using 316 stainless steel powder, carbon and titanium powder as raw materials. Microstructure of the nanocomposite powder was investigated with XRD and TEM techniques. The results showed that the stainless steel/TiC nanocomposite powder obtained when the ball-milling time was more than 40 hours. DSC analysis method was used to study the characteristics of oxidation resistance and the oxidation reaction kinetics of the nanocomposites powder. Results show that the oxidant resistance of nanocomposite powder was improved, the activation energy of oxidation reaction increased.

scholarly journals Reaction sintering of the 2ZnO-TiO2 system

2007 ◽  
Vol 39 (2) ◽  
pp. 127-132 ◽  
Author(s):  
N. Obradovic ◽  
N. Labus ◽  
T. Sreckovic ◽  
S. Stevanovic
Keyword(s):  
Activation Energy ◽  
Ball Mill ◽  
High Energy ◽  
Reaction Sintering ◽  
Constant Heating Rate ◽  
Time Intervals ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Constant Heating ◽  
Kinetics Of

Sintering kinetics of the mechanically activated ZnO-TiO2 system was studied. Mixtures of ZnO and TiO2 powders were mechanically activated using a high-energy ball mill for different time intervals from 0 to 300 minutes. Formal phenomenological analyses were performed in order to describe the specimen?s behavior during isothermal sintering at 1100oC. Non-isothermal sintering was investigated by dilatometer measurements up to 1100oC with a constant heating rate. The Dorn method was applied in order to give information on the activation energy. .

scholarly journals The Influence of Tribophysical Activation on Zn2TiO4 Synthesis

2006 ◽  
Vol 518 ◽  
pp. 131-136 ◽  
Author(s):  
N. Obradović ◽  
Nebojsa Labus ◽  
Tatjana Srećković ◽  
Momcilo M. Ristić
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ball Mill ◽  
High Energy ◽  
Time Intervals ◽  
Powder Morphology ◽  
High Energy Ball Mill ◽  
Microstructure Parameters ◽  
Energy Ball ◽  
Scanning Electron

The influence of tribophysical activation on Zn2TiO4 synthesis along with the changes in powders during tribophysical treatment was observed. Mixtures of ZnO and TiO2 powders were mechanically activated using a high-energy ball mill at different time intervals from 0 to 300 minutes. XRD was performed in order to obtain information about phase composition variations. Microstructure parameters were revealed from an approximation method. Particle size distribution along with scanning electron microscopy gave very useful information about powder morphology.

Characterization of thermal barrier coatings formed by electon-beam physical vapor deposition (EB-PVD)

1989 ◽  
Vol 47 ◽  
pp. 426-427
Author(s):  
Ozer Unal
Keyword(s):  
Thermal Barrier Coatings ◽  
Physical Vapor Deposition ◽  
Ceramic Coating ◽  
High Vacuum ◽  
Ceramic Coatings ◽  
High Energy ◽  
Thermal Barrier ◽  
Protective Oxide ◽  
Barrier Coatings ◽  
Energy Beam

Interest in ceramics as thermal barrier coatings for hot components of turbine engines has increased rapidly over the last decade. The primary reason for this is the significant reduction in heat load and increased chemical inertness against corrosive species with the ceramic coating materials. Among other candidates, partially-stabilized zirconia is the focus of attention mainly because ot its low thermal conductivity and high thermal expansion coefficient.The coatings were made by Garrett Turbine Engine Company. Ni-base super-alloy was used as the substrate and later a bond-coating with high Al activity was formed over it. The ceramic coatings, with a thickness of about 50 μm, were formed by EB-PVD in a high-vacuum chamber by heating the target material (ZrO2-20 w/0 Y2O3) above its evaporation temperaturef >3500 °C) with a high-energy beam and condensing the resulting vapor onto a rotating heated substrate. A heat treatment in an oxidizing environment was performed later on to form a protective oxide layer to improve the adhesion between the ceramic coating and substrate. Bulk samples were studied by utilizing a Scintag diffractometer and a JEOL JXA-840 SEM; examinations of cross-sectional thin-films of the interface region were performed in a Philips CM 30 TEM operating at 300 kV and for chemical analysis a KEVEX X-ray spectrometer (EDS) was used.

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