scholarly journals Formation of Solid Lubricants during High Temperature Tribology of Silver-Doped Molybdenum Nitride Coatings Deposited by dcMS and HIPIMS

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1415
Author(s):  
Martin Fenker ◽  
Martin Balzer ◽  
Sabine Kellner ◽  
Tomas Polcar ◽  
Andreas Richter ◽  
...  
Keyword(s):  
High Temperature ◽  
Magnetron Sputtering ◽  
Elevated Temperatures ◽  
Indentation Test ◽  
Solid Lubricants ◽  
Industrial Applications ◽  
Film Deposition ◽  
Molybdenum Oxides ◽  
Molybdenum Nitride ◽  
X Ray

The coating system MoN-Ag is an interesting candidate for industrial applications as a low friction coating at elevated temperatures, due to the formation of lubricous molybdenum oxides and silver molybdates. Film deposition was performed by high-power impulse magnetron sputtering and direct current magnetron sputtering. To facilitate a future transfer to industry Mo-Ag composite targets have been sputtered in Ar/N2 atmosphere. The chemical composition of the deposited MoN-Ag films has been investigated by wavelength dispersive X-ray spectroscopy. Morphology and crystallographic phases of the films were studied by scanning electron microscopy and X-ray diffraction. To obtain film hardness in relation to Ag content and bias voltage, the instrumented indentation test was applied. Pin-on-disc tribological tests have been performed at room temperature and at high temperature (HT, 450 °C). Samples from HT tests have been analyzed by Raman measurements to identify possible molybdenum oxide and/or silver molybdate phases. At low Ag contents (≤7 at.%), coatings with a hardness of 18–31 GPa could be deposited. Friction coefficients at HT decreased with increasing Ag content. After these tests, Raman measurements revealed the MoO3 phase on all samples and the Ag2Mo4O13 phase for the highest Ag contents (~23–26 at.%).

The Application of X-Ray Diffraction at Elevated Temperatures to Study the Mechanism of Formation of Sodium Tripolyphosphate

1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Amorphous Phase ◽  
Elevated Temperatures ◽  
Sodium Tripolyphosphate ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Temperature Form ◽  
High Temperature Form

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.

Technological Features of the Thick Tin Film Deposition by with Magnetron Sputtering Form Liquid-Phase Target

2018 ◽  
Vol 781 ◽  
pp. 8-13 ◽  
Author(s):  
Mariya Makarova ◽  
Konstantin Moiseev ◽  
Alexander Nazarenko ◽  
Petr Luchnikov ◽  
Galina Dalskaya ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Magnetron Sputtering ◽  
Deposition Rate ◽  
Amorphous Structure ◽  
Film Deposition ◽  
High Deposition Rate ◽  
Crucible Material ◽  
Tin Films ◽  
X Ray ◽  
Tin Film

Technological features of obtaining of tin films in a vacuum by liquid-phase target magnetron sputtering were reviewed. With high deposition rate the white color tin coating with amorphous structure is formed on the substrate. X-ray microanalysis of the obtained tin films showed the presence of micro-and nanoparticles of an impurity of the crucible material in the structure of the films. The use of the tantalum crucible with liquid-phase target magnetron sputtering with deposition rate of 3.2 μm / min allows obtaining ultra-pure, continuous, homogeneous tin film on a stationary substrate without impurity material of the crucible.

Tribological Behavior of Ni-Based Self-Lubricating Composites at Elevated Temperatures

2015 ◽  
pp. 72-106
Author(s):  
Jianliang Li ◽  
Dangsheng Xiong ◽  
Yongkun Qin ◽  
Rajnesh Tyagi
Keyword(s):  
High Temperature ◽  
Friction And Wear ◽  
Solid Lubricant ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Solid Lubricants ◽  
Friction And Wear Behavior ◽  
Nickel Base ◽  
Self Lubricating Composites

This chapter illustrates the effect of the addition of solid lubricants on the high temperature friction and wear behavior of Ni-based composites. Ni-based composites containing solid lubricant particles both in nano and micrometer range have been fabricated through powder metallurgy route. In order to explore the possible synergetic action of a combination of low and high temperature solid lubricant, nano or micro powders of two or more solid lubricants were added in the composites. This chapter introduces the fabrication of the Ni-based self-lubricating composites containing graphite and/or MoS2, Ag and/or rare earth, Ag and/or hBN as solid lubricants and their friction and wear behavior at room and elevated temperatures. The chapter also includes information on some lubricating composite coatings such as electro-deposited nickel-base coating containing graphite, MoS2, or BN and graphene and their tribological characteristics.

scholarly journals Comparative Study of ZnO Thin Films Grown on Quartz Glass and Sapphire (001) Substrates by Means of Magnetron Sputtering and High-Temperature Annealing

2019 ◽  
Vol 9 (21) ◽  
pp. 4509
Author(s):  
Weijia Yang ◽  
Fengming Wang ◽  
Zeyi Guan ◽  
Pengyu He ◽  
Zhihao Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Magnetron Sputtering ◽  
Comparative Study ◽  
Quartz Glass ◽  
Photoelectron Spectroscopy ◽  
Zno Thin Films ◽  
High Temperature Annealing ◽  
X Ray ◽  
Glass Substrates

In this work, we reported a comparative study of ZnO thin films grown on quartz glass and sapphire (001) substrates through magnetron sputtering and high-temperature annealing. Firstly, the ZnO thin films were deposited on the quartz glass and sapphire (001) substrates in the same conditions by magnetron sputtering. Afterwards, the sputtered ZnO thin films underwent an annealing process at 600 °C for 1 h in an air atmosphere to improve the quality of the films. X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectra, photoluminescence spectra, and Raman spectra were used to investigate the structural, morphological, electrical, and optical properties of the both as-received ZnO thin films. The ZnO thin films grown on the quartz glass substrates possess a full width of half maximum value of 0.271° for the (002) plane, a surface root mean square value of 0.50 nm and O vacancies/defects of 4.40% in the total XPS O 1s peak. The comparative investigation reveals that the whole properties of the ZnO thin films grown on the quartz glass substrates are comparable to those grown on the sapphire (001) substrates. Consequently, ZnO thin films with high quality grown on the quartz glass substrates can be achieved by means of magnetron sputtering and high-temperature annealing at 600 °C.

scholarly journals Amorphous Mg–Fe silicates from microwave-dried sol–gels

2019 ◽  
Vol 624 ◽  
pp. A136
Author(s):  
S. P. Thompson ◽  
A. Herlihy ◽  
C. A. Murray ◽  
A. R. Baker ◽  
S. J. Day ◽  
...  
Keyword(s):  
High Temperature ◽  
Powder Diffraction ◽  
Elevated Temperatures ◽  
Sol Gel ◽  
Microwave Drying ◽  
Drying Methods ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Context. Laboratory analogues can provide physical constraints to the interpretation of astronomical observations of cosmic dust but clearly do not experience the same formation conditions. To distinguish between properties intrinsic to the material and properties imprinted by their means of formation requires extensive characterisation. Aims. Sol–gel methods can produce amorphous silicates with potentially high reproducibility, but often require long drying times (24+ h) at elevated temperatures in air, controlled atmosphere, or vacuum. We investigate the possibility that microwave drying can be used to form amorphous silicate on a timescale of ∼10 min and characterise their structural and spectroscopic properties relative to silicates produced by other drying methods. Methods. Microwave-dried amorphous MgSiO3, Fe0.1Mg0.9SiO3 and Mg2SiO4 are characterised using X-ray powder diffraction, total X-ray scattering, small angle X-ray scattering and mid-IR FTIR spectroscopy, and compared to samples produced from the same gels but dried in-air and under vacuum. The development of crystalline structure in the microwave-dried silicates via thermal annealing up to 999°C is also investigated using in situ X-ray powder diffraction. Results. At the inter-atomic level the silicate structures are largely independent of drying method, however larger-scale structured domains, ranging from a ∼few × 10 Å to ∼100’s Å in size, are observed. These are ordered as mass fractals with discernible variation caused by the drying processes. The mid-IR 10 μm band profile is also found to be influenced by the drying process, likely due to the way removal of water and bonded OH influences the distribution of tetrahedral species. However, microwave drying also allows Fe to be easily incorporated into the silicate structure. In situ annealing shows that for amorphous MgSiO3 crystalline forsterite, enstatite and cristobalite are high temperature phases, while for Mg2SiO4 forsterite crystallises at lower temperatures followed by cristobalite at high temperature. For Fe0.1Mg0.9SiO3 the crystallisation temperature is significantly increased and only forsterite is observed. Crystalline SiO2 may be diagnostic of Mg-rich, Fe-poor grain mineralogies. The results are discussed in relation to the different thermal conditions required for dust to crystallise within protoplanetary disk lifetimes. Conclusions. Sol–gel microwave drying provides a fast and easy method of producing amorphous Mg- and Fe,Mg-silicates of both pyroxene and olivine compositions. Their structure and spectroscopic characteristics although similar to silicates produced using other drying methods, exhibit subtle variations which are particularly manifest spectroscopically in the mid-IR, and structurally over medium- and long-range length scales.

Incommensurately modulated ordering of tetrahedral chains in Ca2Fe2O5 at elevated temperatures

2005 ◽  
Vol 61 (6) ◽  
pp. 656-662 ◽  
Author(s):  
Hannes Krüger ◽  
Volker Kahlenberg
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray ◽  
Left Handed ◽  
Lattice Periodicity

The basic building units of brownmillerite-type A 2 B 2O5 structures are perovskite-like layers of corner-sharing BO6 octahedra and zweier single chains of BO4 tetrahedra. A three-dimensional framework is formed by alternate stacking of octahedral layers and sheets of tetrahedral chains. The compound Ca2Fe2O5 is known to have Pnma symmetry at ambient conditions. The space group Imma was reported to be evident above 963 K. New high-temperature single-crystal X-ray diffraction experiments at 1100 K revealed that Ca2Fe2O5 forms an incommensurately modulated structure adopting the superspace group Imma(00γ)s00, with γ = 0.588 (2). The modulation affects the sequence of the enantiomorphic (right- and left-handed) oriented tetrahedral chains within the layer, breaking the lattice periodicity along c. This ordering can be modelled with crenel occupation modulation functions for the tetrahedrally coordinated Fe, as well as for the O atom interconnecting the tetrahedra.

Triethanolamine Molybdate, a New Polymeric Precursor for Molybdenum Nitride

2007 ◽  
Vol 29-30 ◽  
pp. 195-198
Author(s):  
S. Mondal ◽  
A.K. Banthia
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Transition Metal ◽  
Niobium Nitride ◽  
Metal Nitrides ◽  
Molybdenum Nitride ◽  
Transition Metal Nitrides ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
X Ray

Nitrides remain a relatively unexplored class of materials primarily due to the difficulties associated with their synthesis and characterization. Several synthetic routes, including high temperature reactions, microwave assisted synthesis, and the use of plasmas, to prepare binary and ternary nitrides have been explored. Transition metal nitrides form a class of materials with unique physical properties, which give them varied applications, as high temperature ceramics, magnetic materials, superconductors or catalysts. They are commonly prepared by high temperature conventional processes, but alternative synthetic approaches have also been explored, more recently, which utilize moderate temperature condition. Transition metal nitrides particularly, molybdenum nitride, niobium nitride, and tungsten nitride have important applications as catalyst in hydrodenitridation reactions. These nitrides have been traditionally synthesized using high temperature nitridation treatments of the oxides. The nitridation temperatures are very high (> 800- 1000 oC). The aim of our work is to synthesize molybdenum nitride by a simple, low-temperature route. The method involves pyrolysis of a polymeric precursor, which was prepared from the condensation reaction between triethanolamine and molybdic acid. The melting point of the product is 180oC. The polymeric precursor and its pyrolyzed products are characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). X-ray diffraction shows that molybdenum nitride (MoN) obtained from this method has hexagonal crystal structure. MoN is obtained by this method at very low temperature (~ 400 oC).

Properties of WS2 Films Prepared by Magnetron Sputtering from a Nanostructured Target

2013 ◽  
Vol 872 ◽  
pp. 197-200 ◽  
Author(s):  
Yuriy Irtegov ◽  
Vladimir V. An ◽  
Philippe Vinatier ◽  
Nikolay Sochugov ◽  
Alexander Zakharov
Keyword(s):  
High Temperature ◽  
Magnetron Sputtering ◽  
Film Growth ◽  
Tungsten Disulfide ◽  
Main Phase ◽  
Temperature Synthesis ◽  
X Ray ◽  
Growth Orientation ◽  
High Temperature Synthesis ◽  
Nanostructured Target

Tungsten disulfide films were prepared by magnetron sputtering from a laboratory and a nanostructured targets. The nanostructured target was produced from WS2 nanolamellar particles prepared by self-propagating high-temperature synthesis in argon. The main phase in the films was 2H-WS2. According to the X-ray analysis, the films sputtered from the laboratory target and from the nanostructured one reveal different planes of film growth orientation.

Ionic Transport under Chemical Potential Gradients - Kinetic Demixing and Decomposition in Metal Oxides and Scale Growth in High-Temperature Oxidation

2011 ◽  
Vol 696 ◽  
pp. 28-33
Author(s):  
Manfred Martin
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Elevated Temperatures ◽  
Chemical Potential ◽  
Transport Processes ◽  
Temperature Oxidation ◽  
X Ray ◽  
Kinetic Decomposition ◽  
Potential Gradients

In oxides which are exposed to thermodynamic potential gradients, transport processes of the mobile components occur. These transport processes and the coupling between different processes are not only of fundamental interest, but are also the origin of degradation processes, such as kinetic demixing, kinetic decomposition, and changes in the morphology of the material. The kinetics of high temperature oxidation processes of metals can be studiedin situby X-ray absorption spectroscopy (XAS), optical microscopy and X-ray diffraction (XRD) at elevated temperatures and defined oxygen partial pressures. As an example, thein situXAS investigation of the oxidation of cobalt, forming layers of CoO and Co3O4, will be discussed.

scholarly journals Mechanical and Microstructural Characterization of Arc-Welded Inconel 625 Alloy

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3690
Author(s):  
Daniel Kotzem ◽  
Lucas Beermann ◽  
Mustafa Awd ◽  
Frank Walther
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Dendritic Structure ◽  
Microstructural Characterization ◽  
Industrial Applications ◽  
High Yield ◽  
Inconel 625 ◽  
Compression Tests ◽  
Static Compression ◽  
Aerospace Material

The objective of this work was to verify a relatively new fusion-based additive manufacturing (AM) process to produce a high-temperature aerospace material. The nickel-based superalloy Inconel 625 (IN625) was manufactured by an arc-based AM technique. Regarding microstructure, typical columnar-oriented dendritic structure along the building direction was present, and epitaxial growth was visible. The mechanical behavior was characterized by a combination of quasi-static tensile and compression tests, whereas IN625 showed high yield and ultimate tensile strength with a maximum fracture strain of almost 68%. Even quasi-static compression tests at room and elevated temperatures (650 °C) showed that compression strength only slightly decreased with increasing temperature, demonstrating the good high-temperature properties of IN625 and opening new possibilities for the implementation of arc-based IN625 in future industrial applications.

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