摘要:

Mechanical behavior of Al2O3-based ceramics can be improved by dispersion of pure or partially stabilized ZrO2particles. The effective toughening or strengthening effect, which is operating in these composite materials, is determined by microstructural characteristics (composition, processing conditions) and environmental conditions (temperature, loading rate,…).

ISSN:1040-2004    

DOI:10.1080/10402008908981865

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper attempts to answer the question why soft abrasives can sometimes were hard materials. The hardened 35Mn2 steel specimens were tested with a rubber wheel testing apparatus. Different results were obtained at different velocities. At a high velocity, various shapes of tongues on the worn tracks and wear debris were found. The debris can be classified as one of three kinds: spherical, debris with round edges, and chip-like. The appearance of debris and tongues indicates that during the wear process, frictional heat accumulated on the metal surface, the surface layer was softened and even fused so that its hardness drastically decreased, and wear occurred. In this case, soft-abrasive wear has transformed into hard-abrasive wear. Measurements of high temperature hardness indicate that the transformation point, at which the hardness of the specimen decreased to that of the coal used as the abrasive, is about 830°C. A suggestion is also provided for selection of wear-resistant materials.

ISSN:1040-2004    

DOI:10.1080/10402008908981866

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This printing supersedes the publication in the July, 1988 Tribology Transactions pages 382-390 in which Fig. 16 and Table 5 were omitted along with the Discussion and Closure.

ISSN:1040-2004    

DOI:10.1080/10402008908981867

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Performance prediction of squeeze film bearing dampers depends largely on the extent and type of cavitation taking place within the squeeze film land. The investigation described here was intended to probe the phenomenon of cavitation in squeeze film dampers and provide some insight, answers, and possible explanations for some of the measurements and behavior which are generally not predicted by classical lubrication theory. High speed photography was utilized to verify the occurance of vapor cavitation, as well as that of gaseous cavitation which later developed into a two phase homogeneous mixture of oil and air when the test rig was operated at higher speeds. Video recordings at slower speeds showed a blurred image of the trace the bubbles moved through and thus provided a visual record of the flow reversal and oscillatory motion in the squeeze film damper.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981868

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor