摘要:

Chemical analytical instrumentation and advanced surface analysis techniques were combined with X-ray diffraction to investigate the chemistry and the crystal structure of the well-known Ga/In/WSe2self-lubricating compact. The data indicate that the active ingredients within the compact are the lamellar gallium and indium selenides formed during the cure of this material. These solid lubricants work in conjunction with the residual WSe2not yet reduced by the Ga/In during the cure cycle. The binder encapsulant holding the lubricative entities together is the residual Ga/In eutectic, partially reacted to substoichiometric selenides of mostly indium. The high-temperature, tribooxidative resistance of the compact is attributed to a protective mechanism, whereby the substoichiometric indium selenides preferentially oxidize. The oxide network becomes a diffusion shield to the encapsulated, lamellar ingredients. The practical use of the compact is limited by inherent thermodynamic instability problem at elevated temperatures, and the removal of the protective oxide layers by tribological action.Presented at the 39th Annual Meeting in Chicago, Illinois, May 7—10, 1984

ISSN:0569-8197    

DOI:10.1080/05698198508981616

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Two first-order equations are given connecting geometry and internal motions in an angular-contact ball bearing. Total speed, kinematic equivalence, basic speed ratio, and modal speed ratio are defined and discussed; charts are given for the speed ratios covering all bearings and all rotational modes. Instances where specific first-order assumptions might fail are discussed, and the resulting effects on bearing performance reviewed.Presented at the 39th Annual Meeting in Chicago, Illinois May 7—10, 1984

ISSN:0569-8197    

DOI:10.1080/05698198508981617

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Modern design concepts for heat engines with increased thermal efficiency call for the utilization of ceramic components. In some applications, lubrication of these components will be difficult to maintain. Consequently, a need exists for an expanded understanding of the dry sliding wear behavior of ceramics.

ISSN:0569-8197    

DOI:10.1080/05698198508981618

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A squeeze-film damper, consisting of two circular plates, having only normal oscillatory relative motion is considered. The liquid lubricant between the plates is assumed to contain a single central gas bubble. The effect of the bubble on the damper performance is analyzed. Comparison is made with the performance of a pure liquid damper. Substantial deviations in peak dynamic pressures are predicted which explain discrepancies between experimental and theoretical result reported in the literature.Presented at the 39th Annual Meeting in Chicago, Illinois, May 7–10, 1984

ISSN:0569-8197    

DOI:10.1080/05698198508981619

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Mechanical seals are used as sealing devices of water pumps in cooling systems of automobile engines. It is observed that water pump seals sometimes generate a “ringing” sound under certain conditions; however, the mechanisms of “ringing” phenomena have rarely been studied because of the difficulty in reproducing these phenomena.

ISSN:0569-8197    

DOI:10.1080/05698198508981620

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Erosion debris particles produced by particle impact erosion of pure Ni and a stainless steel have been examined in the scanning electron microscope for the purpose of determining whether micro-machining is an operative mechanism of erosion by alumina particles. Macroscopic machining chips generally exhibit well-defined lamellae on the side of the chip away from the tool face, and such lamellae are also observed in micromachining chips produced by abrasion or scratch testing. The aspect ratio of such chips is generally large. In the present work, the aspect ratios and shapes of erosion debris particles formed at angles of incidence below the peak erosion angle (αc) were generally consistent with the dimensions of the impact craters formed on the eroded surface and with the hypothesis that they were formed by micromachining. However, most of the debris particles did not exhibit characteristic lamellae. This may be explained by the fact that the surface from which they are formed is very rough even on a scale similar to the size of the debris particles. This is not true in abrasion: Micromachining chips formed from such a surface would be expected to have surfaces which would obscure the existence of lamellae. However, some chips would be expected to come from the few relatively smooth areas of the surface, and these should show lamellae. Examples of such chips were, indeed, found, and micrographs of these chips are nearly indistinguishable from micrographs of micromachining chips formed by abrasion or scratch tests. It is concluded that micromachining is an operative mechanism of erosion which is of greatest importance at low angles of incidence. Debris particles formed at higher angles of incidence are generally more platelike.Presented at the 39th Annual Meeting, in Chicago, Illinois, May 7–10, 1984

ISSN:0569-8197    

DOI:10.1080/05698198508981621

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor