摘要:

Direct infrared spectrophotometric evidence of interactions between lubricating oil dispersants and a zinc dialkylphosphorodithioate (ZDP) is presented. Increasing the concentration of the dispersants polyamino monoalkenylsuccinimide, barium thiophosphonate, and basic barium dinonylbenzene sulfonate in a mineral oil containing 1.2% by weight of a ZDP decreased the intensity of the phosphorus-oxygen-carbon and phosphorus-sulfur infrared bands, and caused the appearance of a new band at 668 cm−1. The dispersants barium dinonylnaphthalene sulfonate, calcium petroleum sulfonate, and alkaline petroleum sulfonate decreased the intensity of the phosphorus-sulfur bands only after the solutions had aged, and independently of dispersant concentration.

ISSN:0569-8197    

DOI:10.1080/05698197108983221

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Titanium alloys designed for aerospace applications are extremely difficult to grind. Although the high strength of these alloys is a major cause of poor grindability, chemical adhesion of the titanium to the abrasive grain is also a factor contributing to poor abrasive performance. These difficulties can be alleviated by proper choice of grinding fluid. This paper describes work in which coated abrasives are used to grind a titanium alloy (6Al-4V) using water, various soluble cutting oils, and inorganic phosphate solutions as coolants and lubricants. Although some of the highly compounded commercial cutting fluids substantially increase belt efficiency, far greater improvement is obtained with solutions of tri-potassium phosphate. Straight solutions of this material have the added advantage of being moderately good corrosion inhibitors but are a nuisance because of their high pH (alkalinity). Data are presented to show that these solutions retain their effectiveness at nearly neutral pH when properly buffered, thus eliminating the nuisance. Both constant infeed and constant load grinding experiments are described.Presented at the 25th ASLE Annual Meeting in Chicago, May 4–8, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983222

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The sliding performance of polyalkenes in rubbing contact with a metal (oxide) surface is controlled by structural order and molecular symmetry.

ISSN:0569-8197    

DOI:10.1080/05698197108983223

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The friction and wear behavior of steel (soft, medium, and hard), titanium, aluminum, copper and copper beryllium sliding on a wide hardness range of steel plates was measured in both vacuum and air. The wear mechanism was identified for each test by visual and metallographic inspection and by microhardness traverses below the wear interface. Four mechanisms were observed and their occurrence correlated with alloy couple, hardness variations, and vacuum conditions. In addition to prow formation, which has been discussed in the literature, three distinct types of rider wear mechanism are herein identified and defined as severe, intermediate and mild rider wear. The mechanisms are: 1) Prow formation: Characterized by a build up on the slider tip of work hardened wear debris (usually from the plate), which separates the plate from the slider. The sliding interface is in the plate below the prow and friction is governed by plate metal properties. 2) Severe rider wear: Metal is worn off the rider and is transferred and cold welded to the plate. The sliding interface is in the rider and friction is governed by rider material strength. 3) Intermediate rider wear: Metal is removed from the rider but little or none is cold welded to the plate. The sliding interface is intermittent between slider and plate, and friction tends to vary with plate metal hardness. 4) Mild rider wear: A small amount of metal is removed from the slider but plate metal oxides are not penetrated to any degree and no cold welding takes place. Damage to rider and plate is minimal. Friction is governed by plate surface characteristics and is independent of plate hardness.

ISSN:0569-8197    

DOI:10.1080/05698197108983224

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

“Smearing” or “galling” type failures similar to those which occur at sliding contacts in rolling bearings were studied using a number of lubricants in a two-ball sliding tester. The rolling speed, sliding speed, oil flow rate, ambient temperature, rate of increase in load, and ball surface roughness were found to influence the load at which smearing occurred. The results suggest that an elastohydrodynamic film of lubricant plays a major role in determining the load at which smearing occurs. This conclusion was supported by measurements of the oil film thickness using an X-ray transmission technique. Extrapolation from thermocouple measurements indicated that the onset of smearing was not characterized by a constant critical value of the maximum contact temperature.Presented at the 25th ASLE Annual Meeting in Chicago, May 4–8, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983225

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

An analytic expression/or the steady-state interfacial temperature field in a sliding circular Hertzian contact is derived, taking into account the ellipsoidal distribution of the frictional power and the difference between the bulk temperatures of the two bodies, for the case where one surface is stationary and the other rapidly moving with respect to the contact. Other cases may be treated in a similar manner. It is shown that the temperature at any point on the interface can be approximated, to an accuracy improving with velocity, by half the harmonic mean of the two surface temperatures attained at that point if each body were to receive all the frictional power. The resulting maximum flash temperature is 33–38% higher than that given by Blok's widely used formula.Presented at the 25th ASLE Annual Meeting in Chicago, May 4–8, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983226

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The abrasiveness of molybdenum disulfide hat been studied on a Modified LFW-1 Tester Tester. Test rings, coated with a special banded solid lubricant, were rotated under load against uncoated, highly polished, steel test blocks. After each test, the block surface roughness was measured using an electronic surface comparator. Results indicate that randomly oriented platelets of MoS2embedded in a resin, can rapidly cause severe damage to hard metal surfaces, even under relatively light loads. It Was found that run-in is effective in reducing surface damage and that in some cases the effect may he enhanced by burnishing prior to test. Burnishing was found to be effective in inhibiting blister formation.

ISSN:0569-8197    

DOI:10.1080/05698197108983227

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The disulfides and diselenides of the second and third row transition metals from Groups 4 through 7 have been studied for their ability to function as solid lubricants. These materials have similar layered crystal structures. This work has shown that only those with the MoS2type structure and a minimum value of the axial ratio of lattice parameters have inherent lubricating ability. The minimum axial ratios for low sliding friction have been experimentally established as 1.93 and 1.96, respectively, for second and third row transition metals. A rigid sphere atomic model shows that low friction sliding cannot take place unless the axial ratio exceeds 1.87.

ISSN:0569-8197    

DOI:10.1080/05698197108983228

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Results are reported of an analytical study of the character and magnitude of post mechanical interface separation in elastically supported rotary face seals subjected to particular types of input excitation. The seal system is approximated by lump system parameters which permit simulation of its dynamic response. Input forcing functions assigned to the mating ring include harmonic axial shaft pulsation and wobble due to misalignment. The equations of motion governing the seal carrier are solved to determine the character (stable or unstable) and magnitude (relative displacement at seal interface) of post mechanical separation for combinations of system parameters (spring constants, damping ratios, preset, inertia, etc.) and operating conditions (speed, degree of misalignment, amplitude of end play, etc.). For combinations of parameters normally encountered no unstable behavior was observed. However, a reversal of the effects of system damping between pre and post separation behavior did occur.Presented at the 25th ASLE Annual Meeting in Chicago, May 4–8, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983229

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor