Load wear

Voevodin, A. A., Walck, S. D., andZabinski, J. S., Architecture of Multilayer Nanocomposite Coatings with Super-Hard Diamond-Like Carhon Layers for Wear Protechtion at High Contact Load, Wear, Vol. 203-204,1997, pp. 516-527. 

At the end of each interval the average scar diameter is recorded. Two values are generally reported— load wear index (formerly mean Hertz load) and weld point. 

From this test, antiwear and extreme-pressure data were determined, such as welding load, load wear index and wear scar diameter under a load of 40 decanewtons (daN), 60 daN and 80 daN, respectively. First, evaluations were performed on the three original nonmodified hard-core RMs, then evaluations were performed on the sulfur-functionalized ones. Four-ball test data (results only for one concentration 10 wt% additive) are summarized in Table 3.9 (Delfort et al., 1995 and 1999) for ... 

Modified hard-core RMs by phosphosulfurized compound. Improved extreme-pressure and antiwear properties have also been obtained with the introduction of some chemical species, such as sulfur, phosphorus or boron derivatives, into the colloidal core (Delfort et al., 1998 Inoue, 1993 Inoue and Nose, 1987). Welding loads, load wear index and wear scar diameter at 5 wt% of a CaC03 core surrounded by a calcium alkylaryl-sulfonate surfactant shell, and modified by phosphosulfurized calcium carbonate core were evaluated for calcium dialkyl dithiophosphate (CaDTP) and calcium trithiophosphate (CaTTP) with the four-ball extreme-pressure test (ASTM D2783 standard method). Both modified products exhibit improved extreme-pressure performances (welding load and load wear index), while their antiwear properties (wear scar diameter) compared to those of the original micellar substrate remain at least at the same level. 

Welding loads and load wear index at 5 wt% concentration (as the extreme pressure performances) are improved compared to those of the original non-phosphosulfurized substrate (Delfort et al., 1998). The welding load (daN), wear load index (daN) and wear scar diameters (mm) under a load 60 daN behavior are... 

Medium Welding load (daN) Load wear index (daN) Wear scar diameter (mm)... 

Test which is used to determine the relative wear-ball preventing properties of lubricants under boundary test lubrication conditions. Two values are reported - load wear index and weld point from two procedures EP test ASTM D 2596 and wear test ASTM D2266. There are four steel /2-inch balls. Three of the balls are held together in a cup filled with lubricant while the fourth ball is rotated against them. Resistance to motion. 

Figure 13.4 Four-Ball Machine Load/Wear Scar Relationships for Oil with Molybdenum Disulphide or Zinc Dialkyidithiophosphate (Data from Ref,474)...

When tested in the four-ball machine, solutions of sulfur in petroleum oils of moderate viscosity or in white oil raise the critical load for the onset of severe, destructive wear, which is designated as "antiseizure" action in the technological idiom of the four-ball test. Davey [54] found a significant increase in the critical initial seizure load from 834 N (85 kg) for a petroleum base oil to 1275 N (130 kg) for elemental sulfur dissolved in the oil. Sakurai and Sato [55] observed a 3.2-fold increase in the load-wear index (mean Hertz load) for a 0.5 weight-percent solution of elemental sulfur relative to that of the uncompounded white oil. The load-wear index is a specialized result of the four-ball test that can be taken as indicative of the average antiseizure behavior of the lubricant. Mould, Silver and Syrett [56] reported a load-wear index ratio of 3.08 for 0.48% sulfur in white oil relative to that of the solvent oil, and also an increase in the initial seizure load from 441 N to 637 N (45 kg to 65 kg) and in the 2.5-second seizure-delay load from 490 N to 833 N (50 kg to 90 kg). 

Forbes and Silver [40] published data directly comparing the alkyl ester tri-n-butyl phosphate and the aryl ester tricresyl phosphate. Table 11-13 shows the details of this comparison as well as wear data for the acid ester di-n-butyl phosphate. The wear/load index and the initial seizure load show substantially no discrimination between tributyl phosphate and tricresyl phosphate and very little advantage of the compounded oil over the base oil. The low-load wear test distinctly shows better performance with tricresyl phosphate. The data for di-n-butyl phosphate are at variance with the hypothesis that hydrolytic degradation to the acid ester is the first step in the antiwear action of neutral phosphate esters. On the other hand, Bieber, Klaus and Tewksbury [41] separated acidic constituents from commercial tricresyl phosphate by preparative chromatography, and on blending these constituents back into the original tricresyl phosphate at various concentrations they observed enhancement of antiwear action in the four-ball test, as shown in Fig. 11-7. It should be noted that Bieber et at. worked with only 0.051% phosphorus in the lubricant, which may explain the sensitivity they observed to acid impurities. 

Thermal conductivity mW/MK Tensile strength MPa % Elongation Notched Izod impact J/m Coefficient of friction, 3.4 MPa load Wear factor 1/pPa Shore durometer hardness Specific gravity... 

Z. Chen, J. C. Cuneo, J. J. Mecholsky and S. Hu, Damage Processes in Si3N4 Bearing Material Under Contact Loading, Wear, 198,197-207 (1996). 

Other applications are a fluid dam and a valve system washer in a new generation of viscous fan drives for the on-highway truck and agricultural vehicle markets by Borg Warner Automotive Turbo Systems. JCL3030 was selected for the superior combination of thermal resistance, dimensional stability at elevated temperatures under load, wear resistance, and close tolerance by injection-molding capability [2]. 

It should be pointed out here that corrosion processes often involve multiple conjoint effects. Rarely does a single mechanism or event drive corrosion rather, a number of events combine to produce severe effects. Thus, we must keep in mind that corrosion processes usually occur in the context of other factors (loads, wear, crevices, temporally and spatially varying environments, etc.). One such combination of factors can lead to mechanically assisted corrosion in total hip replacements ... 

Dependences of friction torque on time are presented in fig. 18.26, and the mean values of scuffing load, wear-scar diameters of the balls, and wear-scar profiles obtained after the tests in the presence of % aqueous solutions of SML/ESMIS mixtures are shown in figs. 18.27-18.29. 

Musculoskeletal In two cases of osteolysis in hips with third-generation alumina ceramic-on-ceramic couplings, periarticular tissue contained titanium wear debris (from impingement of the neck of the titanium femoral component against the rim of the titanium shell) and ceramic debris (from edge loading wear of the ceramic) [63 ]. The authors could not decide whether the titanium debris, the ceramic debris, or both had caused the osteolysis. 

When the wide or pin end of the link faces the sprocket tooth, all of the sliding between the pin and the bushing bore is under full load. Wear between the pin and the bushing bore is at a maximum. Wear elongation is more rapid in this case, and the chain will need to be replaced more often. 

FIGURE 6.17 Macroscopic pattern of edge-loading wear in a retrieved COC bearing. The wear scar was colored with a marker to facilitate photodocumentation. 

A different behaviour is seen in figure 7, which displays the results on PA6.6. Here, even at low loads, wear increases with an increasing concentration. This implies that no... 

Figure 1 shows schematiceilly a cross section of a surface which contmns a crack (length a) but which is also wearing. Crack tip advance rate may depend on crack length, friction between the crack faces, eind the magnitude and direction of externally applied loads. Wear rate (w) similarly depends on a variety of factors, but its dependence is unlikely to match that of the craick tip advance rate. 

Chen, Z., Cuneo, J., Mecholsky, J.J., Damage processes in Si3N4 bearing material under contact loading. Wear, 198 (19%) 197-207... 

Uses internai/externai iubricant, dispersant, meit flow aid, mold release agent for thermoplastic polymer compounding, esp. in polyamides and impact-modified polyamides dispersant, lubricant for fiber-filled PP, providing rapid wetting of the filler lubricant, mold release agent in thermoplastic PU lubricant in cellulose films and in PVDC when used as a lacquer for cellulose films plasticizer, flow aid for extrusion and inj. molding, reducing machine load, wear, and cycle times Use Level 0.25-1.0% (PP)... 

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