About Some Reasons of Destruction of Gear Details of the Car

It is shown that deformed steel has an advantage over cast steel in terms of mechanical properties. It was revealed that the decrease in the durability of gear parts is associated with the presence of metallurgical defects in the steel. The square segregation is always inherited by the finished part and its appearance on the surface leads to the destruction of the product. The dendritic structure of steel is the reason for the low endurance strength of the tooth of the part. For heavily loaded gear parts of the «shaft-gear» type, it is recommended to use rolled products with a high degree of crimping (extension). To eliminate the dendritic structure in steel, hot deformation of the metal can be carried out at the stage of forging production.

Alloying working surface during electroslag surfacing

Parts subject to intense abrasive wear have a short service life. In the manufacture or restoration of such parts by electroslag surfacing, strengthening of the deposited metal is required. The use of ready-made alloying powders in surfacing increases the cost of the finished part, which necessitates the search for cheaper materials for alloying the parts being welded. The study of the efficiency of alloying the deposited metal through the melted insert, as well as by direct introduction of alloying powders into the slag bath has been carried out. Mixtures based on enriched mineral scheelite concentrate and graphite are used as alloying powders

The Year 1888–1889; With a Winter in Germany

This chapter discusses Anna Botsford and John Henry Comstock's trip abroad to Germany. For a long time, Henry had struggled with the German language, in which so many treatises on zoology were written. He had finally concluded that a winter in Germany was necessary before he finished Part II of the textbook An Introduction to Entomology. Henry at once arranged for his university work under Rudolph Leuckart, the celebrated zoologist. Women were not admitted to the University of Leipsic at that time, but Professor Leuckart permitted Anna to attend one of his lectures, asking only that she came early and departed late—before and after the regular students. Back at Cornell University, after the Germany trip, the summer term of 1889 in entomology was well attended and Henry, as usual, enjoyed the summer teaching very much. He felt that leading his pupils to see the insects living in their natural environment was most important.

The Use of Virtual Manufacturing Features in forward Manufacturing Process Planning

CAPP system is the missing link between CAD/CAM system. Two types of operation of CAPP systems can be distinguished. The first one is the backward process planning, where the part is transformed from its ready state to the stock state. The second method is the forward planning, where the stock is transformed into the finished part. Backward process planning allow for the greater degree of automation, but is difficult for the acceptation among the industrial users. One of the problem in the forward process planning is the necessity to use the manufacturing features which do not occur in the finished part, they occur only in the part intermediate states. The paper propose so called virtual manufacturing features to solve this problem.