scholarly journals INTERACTION WITH A VISCOUS CONTACT WHEN CUTTING AUSTENITIC STEEL WITH A CARBIDE TOOL

Author(s):  
A. Lipatov

On the microsections of chip roots (oblique slices) obtained when turning austenitic steel, carbide tool, studies of the microhardness of the contact area on the front surface. It is established that at zone of viscous-fluid contact when a minimum distance from the front surface the microhardness of the contact area is not change not only along the length of the contact but as the distance from the front surface.

2010 ◽  
Vol 145 ◽  
pp. 399-403
Author(s):  
Ya Qin Tian ◽  
Zhi Fei Wang ◽  
Qing Xue Huang ◽  
Jin Bao Li

In order to study the impact of fulcrum distance on the straightening the minimum fulcrum distance was determined based on the plastic theory according to straightening pressure force in the process of straightening process where there was no indentation. The optimal distance between the fulcrums straightening has been studied by using of bending curvature changes in the bending deflection formula and support the relationship between the dot pitch. Given initial deflection according to bending deflection and bending deflection the amount range of the fulcrum distance can be determined during the pressure straightening. When the rate of bending deflection determined it can obtain the fulcrum distance at the same curvature. The more fulcrums distance the more bending deflection. The minimum fulcrum distance was three times the power growth with the diameter of work piece. The minimum fulcrum distance is inverse proportion to contact area of pressure head. With the pipe wall thickness decreases the minimum distance also reduced.


Author(s):  
Marilena Glovnea ◽  
Emanuel Diaconescu

Many classical applications in machine design and recent ones in the field of electrical contacts or micro-contacts involve surface circular contacts which show important edge effects. To optimize these contacts, a uniform pressure distribution must be generated over an important part of contact area. This requires a specifically profiled front surface. Previously, these authors proposed a solution based on an optimum pressure distribution. This leads numerically to a punch profile which is approximated by a polynomial. The pressure generating this polynomial profile is found and compared to initial proposal. Recent investigations establish a correspondence between a polynomial punch surface and generated pressure. Starting from this correspondence, a new general approach is offered. The same optimum pressure as previously is accepted. Its profile is approximated by a function advanced in the paper. This function yields directly an even polynomial punch profile. Formulae for central pressure and normal approach are derived.


Author(s):  
G. M. Michal ◽  
T. K. Glasgow ◽  
T. J. Moore

Large additions of B to Fe-Ni alloys can lead to the formation of an amorphous structure, if the alloy is rapidly cooled from the liquid state to room temperature. Isothermal aging of such structures at elevated temperatures causes crystallization to occur. Commonly such crystallization pro ceeds by the nucleation and growth of spherulites which are spherical crystalline bodies of radiating crystal fibers. Spherulite features were found in the present study in a rapidly solidified alloy that was fully crysstalline as-cast. This alloy was part of a program to develop an austenitic steel for elevated temperature applications by strengthening it with TiB2. The alloy contained a relatively large percentage of B, not to induce an amorphous structure, but only as a consequence of trying to obtain a large volume fracture of TiB2 in the completely processed alloy. The observation of spherulitic features in this alloy is described herein. Utilization of the large range of useful magnifications obtainable in a modern TEM, when a suitably thinned foil is available, was a key element in this analysis.


2003 ◽  
Vol 112 ◽  
pp. 407-410
Author(s):  
S. A. Danilkin ◽  
M. Hölzel ◽  
H. Fuess ◽  
H. Wipf ◽  
T. J. Udovic ◽  
...  

1993 ◽  
Vol 06 (02) ◽  
pp. 100-104 ◽  
Author(s):  
D. M. Pickles ◽  
C. R. Bellenger

SummaryTotal removal of a knee joint meniscus is followed by osteoarthritis in many mammalian species. Altered load-bearing has been observed in the human knee following meniscectomy but less is known about biochemical effects of meniscectomy in other species. Using pressure sensitive paper in sheep knee (stifle) joints it was found that, for comparable loads, the load-bearing area on the medial tibial condyle was significantly reduced following medial meniscectomy. Also, for loads of between 50 N and 500 N applied to the whole joint, the slope of the regression of contact area against load was much smaller. Following medial meniscectomy, the ability to increase contact area as load increased was markedly reduced.The load bearing area on the medial tibial condyle was reduced following meniscectomy.


The main provisions of the concept of technology of diamond cutting and drilling of building structures are considered. The innovativeness of the technology, its main possibilities and advantages are presented. Carrying out works with the help of this technology in underwater conditions expands its use when constructing and reconstructing hydraulic structure. The use of diamond drilling equipment with motors equipped with an internal combustion engine is considered. Drilling holes with a variable diameter during the reconstruction of the runways of airfields makes it possible to combine the landing mats into a single structure. The ability to cut inside the concrete mass, parallel to the front surface, has no analogues among the methods of concrete treatment. The use of this technology for producing blind openings in the body of concrete without weakening the structure is also unique. Work with precision quality in cutting and diamond drilling of concrete and reinforced concrete was noted by architects and began to be implemented in the manufacture of inter-room and inter-floor openings. Non-destructive approach to the fragmentation of building structures allows them to be reused. The technology of diamond cutting and drilling is located at the junction of new construction, repair, reconstruction of buildings and structures, and dismantling of structures. Attention is paid to the complexity and combinatorial application of diamond technology. Economic efficiency and ecological safety of diamond technology are presented. The main directions of further research for the development of technology are indicated.


Author(s):  
A. H. Sari ◽  
Valiantsin M. Astashynski ◽  
E. A. Kostyukevich ◽  
A. M. Kuzmitski ◽  
V. V. Uglov ◽  
...  

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