scholarly journals Development of a technological complex for thermofriction hardening of products with a circular cross section

2021 ◽  
pp. 65
Author(s):  
Оleg Volkov ◽  
Valeria Subbotinа ◽  
Anna Fedorenko
Keyword(s):  
Cross Section ◽  
High Efficiency ◽  
Circular Cross Section ◽  
Initial State ◽  
Flat Surfaces ◽  
Technological Complex ◽  
High Microhardness ◽  
Different Shapes ◽  
The Cost ◽  
Processing Factors

There are many methods of influencing the structural state of the surface of products of different shapes and different purposes. At the same time, the increase in the relevance of the application of a particular method is closely related to its ability to provide high hardening rates while reducing the cost of such products. The TFН technology has already shown its high efficiency in strengthening surfaces [1]. In addition, studies were conducted on the hardening of surfaces of different profiles [2]. However, the best results are achieved when hardening flat surfaces. In this regard, it is entirely appropriate to conduct research that is related to the development of a technological complex that would include the optimal ratio of processing factors to ensure the necessary level of hardening in the studied objects that have a circular cross-section. Goal. The purpose of this work is to develop a technological complex for processing objects with a circular cross-section. To achieve this goal, metallographic and durometric studies of samples in the initial state and after processing were carried out. At the same time, the changes in the structure and mechanical properties that occur in steel due to processing were studied. Method. The method of thermal friction hardening includes a combined effect of heat and deformation on the treated surface. The peculiarity of this method is the deformation under short-term heating conditions. This makes it possible to further strengthen pre-hardened materials. Results. Under the influence of TFC, significant changes are observed in the structure of cylindrical samples made of 65G steel. This is expressed by the formation of a so-called "white surface layer" in the surface of these samples, which has an ultra-high microhardness [13, 14]. The properties of this layer depend on the initial state of the material, the conditions and modes of conducting TFН.

scholarly journals Geometrical Modeling of Steel Ropes

2013 ◽  
Vol 8 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Eva Stanová
Keyword(s):  
Cross Section ◽  
Geometric Modeling ◽  
Circular Cross Section ◽  
Geometrical Model ◽  
Wire Axis ◽  
Geometrical Modeling ◽  
Steel Rope ◽  
Different Shapes ◽  
The Wire

Abstract The paper deals with the mathematical geometric modeling of the ropes of circular cross- section. Such rope can be formed from strands of different shapes. There is considered steel rope made up of six strands, whose crosssection has oval, triangular or circular profil in this paper. The wires of these types of the strands are presented by parametric equations of the wire axis. The equations are implemented in the Pro/Engineer Wildfire V5 software for creating the geometrical model of the strand.

Milling of Dielectric Ceramics by Fast Argon Atoms

2016 ◽  
Vol 723 ◽  
pp. 329-334
Author(s):  
Sergei Grigoriev
Keyword(s):  
Cross Section ◽  
Circular Cross Section ◽  
Ceramic Materials ◽  
Dielectric Materials ◽  
Ion Milling ◽  
Beam Source ◽  
Plasma Emitter ◽  
Flat Surfaces ◽  
Emissive Grid ◽  
Dielectric Ceramics

A new method for dielectric materials milling has been developed. Instead of well-known ion milling used for metals the dielectrics were processed by broad beams of fast argon atoms. The fast atoms were produced due to charge exchange collisions of accelerated ions. Plasma emitter of the ions was generated in hollow cathode glow discharge. Emissive grid of a circular cross-section beam source consisted of six segments. Energy of the fast atoms ranged from 1 to 3 keV. The beam source was used for production of contoured grooves on flat surfaces of hard ceramic materials. On the surface of movable seal ring made of α-corundum were produced grooves with depth of 20±0.5 μm and roughness of Ra ≈ 0.4 µm. The rate of α-corundum etching amounted to 3 μm/h.

scholarly journals Finite Element Analysis and Investigation on Spinning of Quadrilateral Parts with Hollow Cross-Sections Based on Hypocycloid Theory

2020 ◽  
Vol 10 (23) ◽  
pp. 8588
Author(s):  
Xibin Ou ◽  
Xianyong Zhu ◽  
Peng Gu ◽  
Baichao Wang ◽  
Jing Li ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
High Efficiency ◽  
Circular Cross Section ◽  
Forming Process ◽  
Element Analysis ◽  
Spinning Process ◽  
Specific Geometry ◽  
Von Mises ◽  
Von Mises Stresses

This paper presents research on a new high-efficiency, non-circular spinning method based on hypocycloid theory. The trajectory of the roller during the forming process was derived, and the non-circular spinning process was simulated in ABAQUS 2016/Explicit. The distribution of von Mises stresses and equivalent plastic strains after each spinning pass were analyzed. The spinning quality was also investigated. This research proves the feasibility of spinning the workpieces of a non-circular cross-section using hypocycloid theory. This new non-circular spinning method can be used in practice to produce workpieces with a specific geometry and to increase the rotational speed of the workpiece from 60–240 rpm to 600 rpm, thereby improving the efficiency by around 2.5 times while maintaining acceptable forming quality.

HREM observation of dislocations near room temperature fractures in silicon

1988 ◽  
Vol 46 ◽  
pp. 892-893
Author(s):  
M. H. Rhee ◽  
W. A. Coghlan
Keyword(s):  
Cross Section ◽  
Room Temperature ◽  
Single Crystal Silicon ◽  
Dislocation Nucleation ◽  
Back Side ◽  
Ion Milling ◽  
Crystal Silicon ◽  
Flat Surfaces ◽  
Induced Fractures ◽  
Vicker’S Microhardness

Silicon is believed to be an almost perfectly brittle material with cleavage occurring on {111} planes. In such a material at room temperature cleavage is expected to occur prior to any dislocation nucleation. This behavior suggests that cleavage fracture may be used to produce usable flat surfaces. Attempts to show this have failed. Such fractures produced in semiconductor silicon tend to occur on planes of variable orientation resulting in surfaces with a poor surface finish. In order to learn more about the mechanisms involved in fracture of silicon we began a HREM study of hardness indent induced fractures in thin samples of oxidized silicon.Samples of single crystal silicon were oxidized in air for 100 hours at 1000°C. Two pieces of this material were glued together and 500 μm thick cross-section samples were cut from the combined piece. The cross-section samples were indented using a Vicker's microhardness tester to produce cracks. The cracks in the samples were preserved by thinning from the back side using a combination of mechanical grinding and ion milling.

SAF file: It's really three dimensional file

2018 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Prof. Dr. Jamal Aziz Mehdi
Keyword(s):  
Cross Section ◽  
Root Canal ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Circular Motion ◽  
Root Canal Treatment ◽  
Metal Core ◽  
Rotating Blade

The biological objectives of root canal treatment have not changed over the recentdecades, but the methods to attain these goals have been greatly modified. Theintroduction of NiTi rotary files represents a major leap in the development ofendodontic instruments, with a wide variety of sophisticated instruments presentlyavailable (1, 2).Whatever their modification or improvement, all of these instruments have onething in common: they consist of a metal core with some type of rotating blade thatmachines the canal with a circular motion using flutes to carry the dentin chips anddebris coronally. Consequently, all rotary NiTi files will machine the root canal to acylindrical bore with a circular cross-section if the clinician applies them in a strictboring manner

Effects of openings on the seismic behavior and performance level of concrete shear walls

2019 ◽  
Author(s):  
Hossein Alimohammadi ◽  
Mostafa Dalvi Esfahani ◽  
Mohammadali Lotfollahi Yaghin
Keyword(s):  
Static Analysis ◽  
Cross Section ◽  
Seismic Behavior ◽  
Shear Walls ◽  
Shear Wall ◽  
Constant Cross Section ◽  
Added Resistance ◽  
Different Shapes ◽  
And Performance ◽  
Abaqus Software

In this study, the seismic behavior of the concrete shear wall considering the opening with different shapes and constant cross-section has been studied, and for this purpose, several shear walls are placed under the increasingly non-linear static analysis (Pushover). These case studies modeled in 3D Abaqus Software, and the results of the ductility coefficient, hardness, energy absorption, added resistance, the final shape, and the final resistance are compared to shear walls without opening.

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