A Test of Molybdenum Disulfide Lubricants in Radiation and Vacuum Environments

1969 ◽  
Vol 91 (3) ◽  
pp. 390-395
Author(s):  
J. H. Lewis ◽  
R. H. McDaniel
Keyword(s):  
Environmental Conditions ◽  
Sliding Wear ◽  
Radiation Effects ◽  
Room Temperature ◽  
Radiation Effect ◽  
Aluminum Phosphate ◽  
The Other ◽  
Ball Bearings ◽  
Solid Film ◽  
Wear Tests

Tests have been conducted on two MoS2-base solid-film lubricants, one containing gold and sodium silicate and the other containing bismuth and aluminum phosphate, having potential for application under severe environmental conditions. The lubricant with gold was applied to test races of 440 C steel and Rene´ 41 and exposed with a reactor to 1.5 × 1011 ergs/g(C) of gamma and 8.2 × 1016 neutrons/cm2 (E > 0.1 MeV). The test specimens were subsequently evaluated in sliding-wear tests at temperatures as high as 1200 deg F. Both lubricants were tested in vacuum (∼10−6 torr) and in air on size R-3 ball bearings, which were run at 6000 rpm in servomotors. No significant radiation effects were detected with the MoS2:Au lubricant on 440 C steel in tests at room temperature and 600 deg F. In tests at room temperature, 600 deg F, and 1200 deg F on Rene´ 41, the data indicated a possible radiation effect at 600 deg F but not at the other temperatures. In two vacuum tests on bearings, the MoS2:Au lubricant gave a mean running time of about 110 h. The MoS2:Bi film gave a mean life of 96 h in the first test and 853 h in the second test.

scholarly journals Corrosion and Wear performances analysis of PVD CrMoN/Cr Coatings

10.30544/640 ◽  
2021 ◽  
Vol 27 (3) ◽  
pp. 397-409
Author(s):  
Kheireddine BOUZID ◽  
Rim LAMARI ◽  
Nasser Eddine BELIARDOUH ◽  
Corrine NOUVEAU ◽  
Barnali Biswas
Keyword(s):  
Sliding Wear ◽  
Room Temperature ◽  
Corrosion Potential ◽  
Adhesive Wear ◽  
Uncoated Sample ◽  
Electrochemical Tests ◽  
Wear And Corrosion ◽  
Disc Configuration ◽  
Wear Tests ◽  
Ball On Disc

Tools coated CrN based alloys are currently used in several industries for machining and manufacturing, but present severe wear, limiting their service life. Seeking an alternative, three CrMoN monolayers (~1µm in thickness) coatings with varying in the Mo percentage content were elaborated using the RF magnetron co-sputtering method. These coatings were evaluated and compared with the alloy currently used (CrN) by electrochemical tests in NaCl solution (stationary and no stationary method) and sliding wear tests (ball-on-disc configuration) performed at room temperature. The results indicate that the samples coated with CrMoN presented better performance against wear and corrosion than the uncoated sample. Among the coatings, the labeled C1 (27 % Mo) showed the best corrosion resistance as it presents a positive corrosion potential Ecorr. However, the best wear resistance (lowest coefficient of friction) was shown by coating labeled C4 (33 % Mo). All of the tested specimens underwent abrasive wear in addition to adhesive wear.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

HAYNES STELLITE ALLOY No. 98M2

Alloy Digest ◽  
1960 ◽  
Vol 9 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Physical Properties ◽  
Room Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
The Other ◽  
Stellite Alloy ◽  
Cobalt Base Alloy ◽  
Cobalt Base

Abstract HAYNES STELLITE 98M2 Alloy is a cobalt-base alloy having higher compressive strength and higher hardness than all the other cobalt-base alloys at room temperature and in the red heat range. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: Co-22. Producer or source: Haynes Stellite Company.

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

Tribological Properties of Ti-Al Alloy Self-Lubricating Composite Materials

2013 ◽  
Vol 842 ◽  
pp. 114-117
Author(s):  
Xiu Ling Wang ◽  
Li Ying Yang ◽  
Shou Ren Wang ◽  
Yi Zhang
Keyword(s):  
Sliding Wear ◽  
Solid Lubricant ◽  
Al Alloy ◽  
Test Results ◽  
Weight Percentage ◽  
Dry Conditions ◽  
Hot Pressing Sintering ◽  
Worn Surface ◽  
Wear Tests ◽  
Self Lubricating Composites

A series of Ti-48Al-2Cr-2Nb/62%BaF2-38%CaF2 (CB) self-lubricating composites with addition of different weight percentage of solid lubricant were prepared by vacuum hot pressing sintering. Sliding wear tests against 45#steel were performed on the specimen in dry conditions, worn morphology was observed by the scanning electron microscope (SEM). The test results show that when addition of solid lubricant weight percentage is 10%, the worn surface of the composites is most smooth.The main wear mechanisms of Ti-48Al-2Cr-2Nb/62%BaF2-38%CaF2 composite are abrasive wear and adherent wear.

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

On the Chemistry of Tetrabenzyl Thiuram Disulfide and Tetramethyl Thiuram Disulfide with Bis (Triethoxysilylpropyl) Tetrasulfide in Silica Compounds

2003 ◽  
Vol 76 (4) ◽  
pp. 876-891 ◽  
Author(s):  
R. N. Datta ◽  
A. G. Talma ◽  
S. Datta ◽  
P. G. J. Nieuwenhuis ◽  
W. J. Nijenhuis ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Succinic Anhydride ◽  
Dynamic Properties ◽  
The Other ◽  
Resonance Spectroscopy ◽  
Reaction Products ◽  
Negative Effect ◽  
Higher Temperature ◽  
Analytical Tools

Abstract The use of thiurams such as Tetramethyl thiuram disulfide (TMTD) or Tetrabenzyl thiuram disulfide (TBzTD) has been explored to achieve higher cure efficiency. The studies suggest that a clear difference exists between the effect of TMTD versus TBzTD. TMTD reacts with Bis (triethoxysilylpropyl) tetrasulfide (TESPT) and this reaction can take place even at room temperature. On the other hand, the reaction of TBzTD with TESPT is slow and takes place only at higher temperature. High Performance Liquid Chromatography (HPLC) with mass (MS) detection, Nuclear Magnetic Resonance Spectroscopy (NMR) and other analytical tools have been used to understand the differences between the reaction of TMTD and TESPT versus TBzTD and TESPT. The reaction products originating from these reactions are also identified. These studies indicate that unlike TMTD, TBzTD improves the cure efficiency allowing faster cure without significant effect on processing characteristics as well as dynamic properties. The loading of TESPT is reduced in a typical Green tire compound and the negative effect on viscosity is repaired by addition of anhydrides, such as succinic anhydride, maleic anhydride, etc.

scholarly journals Recent Observations on the Mechanical Properties of Polymer Networks

1971 ◽  
Vol 44 (5) ◽  
pp. 1256-1272 ◽  
Author(s):  
P. Thirion ◽  
R. Chasset
Keyword(s):  
Crosslink Density ◽  
Room Temperature ◽  
Dynamic Properties ◽  
Polymer Networks ◽  
The Other ◽  
Dilution Ratio ◽  
Chain Entanglement ◽  
Influence Of Temperature ◽  
Terminal Zone ◽  
Crosslinking Agents

Abstract The influence of temperature, elongation, swelling or dilution ratio, crosslink density, nature of the polymers, and crosslinking agents on the dynamic properties, creep and relaxation of polymer networks is surveyed in the terminal region of the spectrum. Whereas the deformation does not change the relaxation kinetics in large ranges of extension, the crosslink density acts as a reduced variable apparently accelerating uniformly the viscoelastic processes beyond the glass transition. The other possible reductions ‘time-temperature’ and ‘time—swelling’ do not necessarily seem related to the variations of free volume. From the viewpoint of the explanation of the relaxation mechanisms in the terminal zone, the fact that the equilibrium of loosely crosslinked elastomers would only virtually be reached after several years at room temperature seem in better agreement with chain entanglement effects, either trapped or not by the permanent network, than with the dissociation of secondary linkages.

Dry sliding wear behaviour of AA 6351-ZrB2 in situ composite at room temperature

2010 ◽  
Vol 31 (3) ◽  
pp. 1526-1532 ◽  
Author(s):  
G. Naveen Kumar ◽  
R. Narayanasamy ◽  
S. Natarajan ◽  
S.P. Kumaresh Babu ◽  
K. Sivaprasad ◽  
...  
Keyword(s):  
Sliding Wear ◽  
Room Temperature ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
In Situ Composite ◽  
Sliding Wear Behaviour

CLAY-INORGANIC STUDIES. II. HYDROXY ALUMINUM PHOSPHATE–MONTMORILLONITE COMPLEX

1975 ◽  
Vol 55 (2) ◽  
pp. 225-233 ◽  
Author(s):  
H. KODAMA ◽  
M. D. WEBBER
Keyword(s):  
Relative Humidity ◽  
Room Temperature ◽  
Aluminum Phosphate ◽  
Silicate Layer ◽  
Basal Spacing ◽  
Minor Amount ◽  
Chemical Compositions ◽  
A Minor ◽  
Positively Charged ◽  
Water Contents

Two specimens of hydroxy aluminum phosphate interlayer materials in montmorillonite clay were prepared with 7.20 meq Al and 11.29 meq H3PO4/g clay and with 14.40 meq Al and 22.58 meq H3PO4/g clay, and the resulting complexes studied by chemical and mineralogical methods. Both interlayer materials were slightly positively charged and except for different water contents their chemical compositions were almost identical. They contained Al, PO4 and H2O and a minor amount of Ca and approximated hydrous AlPO4∙nH2O. The mole ratios of Al:Ca:PO4:OH were 1.00:0.08:0.92:0.24 and 1.00:0.05:0.91:0.24, respectively. The interlayer materials appeared to be loosely packed and distributed sparsely in interspaces of the montmorillonite. The degree of packing was greater for the preparation with the larger amount of interlayer material. The materials increased the montmorillonite basal spacing to 23.3 Å under air-dry condition (30–40% relative humidity) but did not affect the lateral dimensions. The basal spacing varied somewhat with relative humidity at room temperature and decreased markedly as water was driven off by heating. Heat treatments between room temperature and 300 C sharply reduced the d001 spacings to 16.7 Å which persisted up to 700 C. It is postulated that the large basal spacings occur because the hydrated interlayer materials have a framework structure with tunnels along the c-axis. This being so, changes in the spacings with different humidities might result from the movement of water molecules among interstitial spaces existing around and between the loosely distributed molecules of interlayer material. The 16.7 Å spacing for the dehydrated phase corresponds to the sum of 7.0 Å, the edge dimension of an orthorhombic anhydrous AlPO4 and 9.7 Å, the silicate layer thickness.

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