Predicting Bearing Performance of Filled Teflon TFE Resins

1967 ◽  
Vol 89 (1) ◽  
pp. 182-186 ◽  
Author(s):  
R. B. Lewis
Keyword(s):  
Surface Temperature ◽  
Bearing Surface ◽  
Temperature Dependent ◽  
Wear Factor ◽  
Severe Wear ◽  
Wear Rates ◽  
Surface Temperatures ◽  
Mild Wear ◽  
New Evidence

The wear rates of filled compositions of Teflon can be reliably predicted using an experimentally determined wear factor if the bearing pressure, velocity, temperature, and geometry are known. New evidence confirms the wear rates are directly proportional to pressure and velocity in both the mild wear regime and the severe wear regime, although the wear factors are much higher in the severe regime. The transition from mild to severe wear is pressure and surface temperature dependent and coincides with (but is not adequately described by) PV limit. An application factor is proposed to relate bearing surface temperatures to PV and geometry.

The dry wear of steels II. Interpretation and special features

1965 ◽  
Vol 257 (1077) ◽  
pp. 51-70 ◽  
Keyword(s):  
Oxide Film ◽  
Phase Change ◽  
Strain Hardening ◽  
Frictional Heating ◽  
Combined Effects ◽  
Phase Hardening ◽  
Special Effects ◽  
Severe Wear ◽  
Wear Rates ◽  
Mild Wear

The pattern of wear outlined in part I is interpreted in the light of further experiments which reveal that the change from severe wear to mild is governed by the hardness and state of oxidation of the surfaces. At light loads (< T 1) severe wear is inhibited by the combined effects of strain hardening and oxidation. At higher loads (> T 2) mild wear recurs primarily as a consequence of a change of phase induced by frictional heating. The hardness accompanying the phase change is great enough, initially, to suppress severe wear without the intervention of an oxide film. At loads immediately above T 2, however, the hardness tends to fall if rubbing is prolonged and oxidation is again essential to preserve the mild wear state. Sustained phase-hardening does not occur until a higher load, roughly coinciding with the T 3 transition, is attained and this finding has an important bearing on the influence of inert atmospheres. The onset of permanent hardening is not responsible for the divergent pin and ring wear rates at T 3, though the phenomena may be linked by the magnitude of the temperatures required to cause phase-hardening; the T 3 transition and the trend at higher loads have been identified as special effects associated with the thermal asymmetry of the rubbing system.

Effect of Counter Surface Temperature and Load on the Transition from Mild to Severe Wear Behavior of Al-Si-SiCp Composites in Reciprocating Conditions

2012 ◽  
Vol 710 ◽  
pp. 551-556
Author(s):  
V.R. Rajeev ◽  
D.K. Dwivedi ◽  
S.C. Jain
Keyword(s):  
Surface Temperature ◽  
Wear Behavior ◽  
Wear Test ◽  
Stir Casting ◽  
Material Loss ◽  
Severe Wear ◽  
Mild Wear ◽  
Sem Study ◽  
Composite Mode ◽  
Counter Surface

In the present paper, the effect of counter surface temperature and load on the transition from mild to severe wear of A319/15%SiCp, A336/15%SiCp, and A390/15%SiCp composites have been reported. Composites were produced through stir casting route. Adhesive wear behavior of composites was studied under dry reciprocating conditions using indigenously developed reciprocating friction wear test rig conforming to ASTM standard G133-05. It was found that increase in counter surface temperature increases wear rate and depending upon the load and type of composite mode of wear changes from mild oxidative to severe metallic wear noticed. At 120N load, the critical transition temperature for all the three Al-Si-SiCp composites was found to be 350°C. SEM study of wear surface and wear debris was conducted to analyze the mode of wear and operating wear mechanism. Severe wear was characterized by massive plastic deformation and gross material removal while the mild wear was found to be associated with delamination and scoring as main wear mechanisms responsible for material loss.

Paper 17: Basic Mechanisms of Wear

1967 ◽  
Vol 182 (1) ◽  
pp. 281-292 ◽  
Author(s):  
W. Hirst
Keyword(s):  
Severe Wear ◽  
Wear Rates ◽  
Mild Wear ◽  
Dry Conditions

This review deals with the wear of conforming and non-conforming surfaces, both lubricated and dry. It covers the scuffing, pitting and mild wear of lubricated surfaces, the range of wear rates in dry conditions, the patterns of wear and the main causes of severe wear.

Application of pyrometer and standard sample to determine surface temperature of studied materials

2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov
Keyword(s):  
Composite Material ◽  
Surface Temperature ◽  
Relative Error ◽  
Wavelength Range ◽  
Standard Sample ◽  
A Priori ◽  
Temperature Changes ◽  
Surface Temperatures ◽  
Relative Errors ◽  
Normal Emissivity

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.

scholarly journals A spatiotemporal reconstruction of sea-surface temperatures in the North Atlantic during Dansgaard–Oeschger events 5–8

2018 ◽  
Vol 14 (6) ◽  
pp. 901-922 ◽  
Author(s):  
Mari F. Jensen ◽  
Aleksi Nummelin ◽  
Søren B. Nielsen ◽  
Henrik Sadatzki ◽  
Evangeline Sessford ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic ◽  
General Circulation ◽  
Sea Surface ◽  
Reconstruction Method ◽  
Sea Surface Temperatures ◽  
Proxy Data ◽  
Surface Temperatures ◽  
Temperature Reconstructions

Abstract. Here, we establish a spatiotemporal evolution of the sea-surface temperatures in the North Atlantic over Dansgaard–Oeschger (DO) events 5–8 (approximately 30–40 kyr) using the proxy surrogate reconstruction method. Proxy data suggest a large variability in North Atlantic sea-surface temperatures during the DO events of the last glacial period. However, proxy data availability is limited and cannot provide a full spatial picture of the oceanic changes. Therefore, we combine fully coupled, general circulation model simulations with planktic foraminifera based sea-surface temperature reconstructions to obtain a broader spatial picture of the ocean state during DO events 5–8. The resulting spatial sea-surface temperature patterns agree over a number of different general circulation models and simulations. We find that sea-surface temperature variability over the DO events is characterized by colder conditions in the subpolar North Atlantic during stadials than during interstadials, and the variability is linked to changes in the Atlantic Meridional Overturning circulation and in the sea-ice cover. Forced simulations are needed to capture the strength of the temperature variability and to reconstruct the variability in other climatic records not directly linked to the sea-surface temperature reconstructions. This is the first time the proxy surrogate reconstruction method has been applied to oceanic variability during MIS3. Our results remain robust, even when age uncertainties of proxy data, the number of available temperature reconstructions, and different climate models are considered. However, we also highlight shortcomings of the methodology that should be addressed in future implementations.

scholarly journals A Novel Quantitative Prediction Approach for Pungency Level of Chinese Liquor (Baijiu) Based on Infrared Thermal Imager

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1107
Author(s):  
Yingxia He ◽  
Shuang Chen ◽  
Ke Tang ◽  
Yan Xu ◽  
Xiaowei Yu
Keyword(s):  
Aqueous Solution ◽  
Surface Temperature ◽  
Sensory Analysis ◽  
Alcoholic Beverages ◽  
Quantitative Prediction ◽  
Thermal Imager ◽  
Surface Temperatures ◽  
Tongue Surface ◽  
Ethanol Aqueous Solution ◽  
Prediction Approach

Pungency is a crucial sensory feature that influences consumers’ appreciation and preferences toward alcoholic beverages. However, the quantitation of pungency is challenging to achieve using sensory analysis because of persistence, accumulation, and desensitization to the pungency perception. This study aimed to design a novel pungency evaluation method based on the measurement of tongue surface temperature. An infrared thermal (IRT) imager technique for measuring tongue surface temperature was established. To validate its feasibility, the IRT technique was used to measure tongue surface temperatures after the tongue was stimulated by (1) water and Baijiu, (2) different concentrations of ethanol aqueous solution (10, 20, 30, 40, and 50%, v/v), (3) ethanol aqueous solution and Baijiu samples with the same ethanol content, and (4) 26 Baijiu samples with different pungency level. For all cases, tongue surface temperatures showed large differences as a result of the different stimulation. The results showed that the tongue surface temperature correlated with the pungency intensity obtained by the sensory analysis. The relationship between tongue surface temperature and pungency intensity was established by multiple linear regression analysis. The IRT technique was able to be a useful support tool to quantitatively predict the pungency of alcoholic beverages, based on the measurement of tongue surface temperature.

Transition of Mild Wear to Severe Wear in Oxidative Wear of H21 Steel

2008 ◽  
Vol 32 (2) ◽  
pp. 67-72 ◽  
Author(s):  
S. Q. Wang ◽  
M. X. Wei ◽  
F. Wang ◽  
X. H. Cui ◽  
C. Dong
Keyword(s):  
Oxidative Wear ◽  
Severe Wear ◽  
Mild Wear

A Study of Thermal Performance on Cool Colorful Water-Based Reflective Coatings for Building

2011 ◽  
Vol 250-253 ◽  
pp. 536-539
Author(s):  
Pei Wang ◽  
Wen Yan Lv ◽  
Zhi Yong Wei ◽  
Xia Zhen Zhang ◽  
Lian Liu ◽  
...  
Keyword(s):  
Comparative Study ◽  
Surface Temperature ◽  
Thermal Performance ◽  
Temperature Difference ◽  
Surface Temperatures ◽  
Water Based ◽  
Reflective Coatings ◽  
Micro Sphere

This paper presented the results of a comparative study aiming to investigate the effect of reflective coatings on lowering surface temperatures of matrix. Moreover, the important factors of the amount and the color of colored hollow-ceramic micro sphere were discussed. It was demonstrated that the use of reflective coatings could reduce a white surface temperature by 6.5 °C compared to a sample. The temperature difference became to reduce while the color of coatings turned to dark from the white to the yellow.

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