Fluid Characteristics of Material Flow in High Speed Metal Cutting Process

2012 ◽  
Vol 500 ◽  
pp. 544-549
Author(s):  
K.G. Zhang ◽  
Zhan Qiang Liu
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Metal Cutting ◽  
Deformation Model ◽  
Rake Face ◽  
Maximum Value ◽  
Finished Surface ◽  
Better Than ◽  
Fluid Characteristics

In high speed metal cutting momentum would be large and the strain rate can be exceedingly high, the viscosity of material must take into account in studying the chip deformation. Model the high speed machining as fluid flow is much better than as solid. A laminar flow method is applied in this paper to analyze the velocity distribution, the pressure distribution, the temperature distribution and the strain rate distribution of high speed metal cutting. Analytical results showed that a speed stagnation point is located at some distance from the tool tip on the tool rake face, on which the maximum value of the pressure occurs, with zero speed; its location influences the life of the tool and the quality of the finished surface. The value of the pressure decrease along the rake face and reaches zero at some point away from the tool tip, which is the point of separation of the chip from the tool; The value of strain rate get a rapid increase from the tool tip to the free surface corner then decreased outwards.

scholarly journals Strain Rate of Metal Deformation in the Machining Process from a Fluid Flow Perspective

2020 ◽  
Vol 10 (9) ◽  
pp. 3057
Author(s):  
Keguo Zhang ◽  
Keyi Wang ◽  
Zhanqiang Liu ◽  
Xiaodong Xu
Keyword(s):  
Fluid Flow ◽  
Strain Rate ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Shear Plane ◽  
Cutting Process ◽  
Machining Process ◽  
Rake Face ◽  
Metal Deformation

Metal cutting speeds are getting faster with the development of high-speed cutting technology, and with the increase in cutting speed, the strain rate will become larger, which makes the study of the metal cutting process more inconvenient. At the same time, with the increase in strain rate, the dislocation movement controlling the plastic deformation mechanism of metal will change from thermal activation to a damping mechanism, which makes the metal deformation behave more like a fluid. Therefore, it is necessary to explore new ways of studying machining from the perspective of fluid flow. Based on this, a fluid model of the metal cutting process is established, and a method for calculating the strain rate is proposed from the point of view of flow. The results of the simulation and measurements are compared and analyzed. The results show that the strain rate on the rake face will be affected by the friction between the chip and tool; the nearer the distance between the chip layer and tool rake face, the bigger the strain rate will be. The strain rate in the central shear plane is much larger than in other areas along the shear plane direction, and in which two ends are the biggest. It can achieve rougher, quantitative research. This shows it is feasible to study machining from the viewpoint of fluid flow, though it still needs a lot of theoretical support and experimental confirmation.

Design and Construction of a High Speed Inter-Row Cultivator

2011 ◽  
Vol 110-116 ◽  
pp. 4914-4918 ◽  
Author(s):  
Yousef Abbaspour-Gilandeh ◽  
Zargham Fazel-Niari ◽  
Gholamhosein Shahgoli ◽  
Malek Bavafa
Keyword(s):  
High Speed ◽  
Soil Layer ◽  
Environmental Concerns ◽  
Row Crops ◽  
Field Displacement ◽  
Finished Surface ◽  
Soil Preparation ◽  
Excellent Method ◽  
Structural Research

In many parts of the world, row crops are treated with herbicides. Because of environmental concerns, crop cultivation is suggested as an excellent method of weed control. The object of this study was to design and construct a high speed inter-row cultivator. The speed of plowing has a significant effect not only on the depth of plowing but on factors which affect the quality of soil preparation such as loosening of the upper soil layer, cutting roots of the previous crops, covering and plowing in of weeds, leveling the finished surface of the field, displacement of the son layer and so on. In this study, the designed and constructed cultivator has a toolbar, unit frame, disk coulter and a flat sweep. The unit frame is attached to a tractor mounted tool bar by a suspension linkage. The suspension linkage allows the unit frame to move up and down relative to a tool bar that the cultivator unit is attached to. The numerical analysis was performed with COSMOS/M 1.71 FEM software (Structural Research and Analysis Corporation, CA).

An Integral Method to Determine Workpiece Flow Stress and Friction Characteristics in Metal Cutting

2015 ◽  
Vol 9 (6) ◽  
pp. 775-781
Author(s):  
Norfariza Wahab ◽  
◽  
Yumi Inatsugu ◽  
Satoshi Kubota ◽  
Soo-Young Kim ◽  
...  
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Edge ◽  
Cutting Process ◽  
Machining Parameters ◽  
Friction Characteristics ◽  
High Speed Cutting

In recent times, numerical simulation techniques have been commonly used to estimate and predict machining parameters such as cutting forces, stresses, and temperature distribution. However, it is very difficult to estimate the flow stress of a workpiece and the friction characteristics at a tool/chip interface, particularly during a high-speed cutting process. The objective of this study is to improve the accuracy of the present method and simultaneously determine the characteristics of the flow stress of a workpiece and friction at the cutting edge under a high strain rate and temperature during the cutting process. In this study, the Johnson-Cook (JC) flow stress model is used as a function of strain, strain rate, and temperature. The friction characteristic was estimated by minimizing the difference between the predicted and measured results of principal force, thrust force, and shear angle. The shear friction equation was used to estimate the friction characteristics. Therefore, by comparing the measured values of the cutting forces with the predicted results from FEM simulations, an expression for workpiece flow stress and friction characteristics at the cutting edge during a high-speed cutting process was estimated.

scholarly journals KUALITAS SEMEN SAPI PEJANTAN SIMMENTAL DAN LIMOUSIN YANG DIPELIHARA DALAM TIPE KANDANG YANG BERBEDA DI BALAI INSEMINASI BUATAN LEMBANG

ZOOTEC ◽  
2020 ◽  
Vol 40 (2) ◽  
pp. 439
Author(s):  
Bastiana Elvira Lagu ◽  
Endang Pudjihastuti ◽  
Umar Paputungan ◽  
Sri Adiani
Keyword(s):  
High Speed ◽  
Semen Quality ◽  
Mass Movement ◽  
Secondary Data ◽  
Test Method ◽  
Spermatozoa Motility ◽  
Different Types ◽  
Animal House ◽  
Better Than

SEMEN QUALITY OF LIMOUSIN AND SIMMENTAL BULLS MAINTAINED IN DIFFERENT TYPES OF PENS AT THE INSTITUTION OF LEMBANG ARTIFICIAL. The intensive maintenance of bulls included animal house and pens protecting animals against sunlight, cool effect, rain, high speed of win and other predators. Objective of this study was to evaluate effects of single bull in a pen (SB) and double bulls in a pen (DB) on semen quality of Limousin and Simmental bulls at the Institution of Lembang Artificial Insemination in West Java. Primer and secondary data of both bulls reproduction were used in this study and analyzed by t test method. Results showed that average volume of semen in both bulls of Limousin and Simmental under SB (9.54 ± 2.19 mL/ejaculation) was significantly higher of 7.67 percents than those of bulls under DB (8.86 ± 1.79 mL/ejaculation). The average of percentage of spermatozoa motility in both bulls of Limousin and Simmental under DB (71.00 ± 2.67) was not significantly differ with those of bulls under SB (70.10 ± 2.37). The average of spermatozoa mass movement in both bulls of Limousin and Simmental under SB (1.84 ± 0.37) was significantly more aggressive of 5.43 percents than those of bulls under DB (1.94 ± 0.24). Finally, the average of pH of semen in both bulls of Limousin and Simmental under SB (6.66 ± 0.11) was not significantly differ with those of bulls under DB (6.64 ± 0.10). Correlation between reproduction variables of both Limousinand Simmental bulls in SB and DB was not correlated between one and another variables indicated by correlation values ranging from -0.29 to 0.18. Based of the result of study can be concluded that semen quality of Limousin and Simental in single pen was better than that in double pens. The correlations among reproductive veriables of Limousin and Simmental in both sigle and double pens had no correlation between one and another variable. Keyword: Type of Pen, Semen Quality, Simmental Bull, Limousin Bull.

The use of assembled cutting tool with damping elements to reduce mechanical vibrations

2021 ◽  
Author(s):  
Keyword(s):  
High Speed ◽  
Metal Cutting ◽  
Cutting Tool ◽  
End Mill ◽  
Mechanical Vibrations ◽  
Machined Surface ◽  
High Speed Cutting ◽  
End Mills ◽  
Cutting Modes

Aspects of vibration reduction during machining on metal-cutting machines to improve the quality of machined surfaces at moderate and high-speed cutting modes are considered. End mills with damping elements made of different materials, which provide the control of tool rigidity, are developed. Keywords: vibrations, end mill, vibrations, machined surface, damping. [email protected]

Hardfacing of metal-cutting tools by arc welding in vacuum

2020 ◽  
Vol 2 (99) ◽  
pp. 49-56
Author(s):  
N.V. Ferdinandov ◽  
D.D. Gospodinov
Keyword(s):  
Wear Resistance ◽  
Heat Resistance ◽  
Arc Welding ◽  
High Speed ◽  
Metal Cutting ◽  
Microstructural Analysis ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Heat Treated ◽  
Better Than

Purpose: To present a technology for hardfacing of metal-cutting tools by arc welding in vacuum. Design/methodology/approach: The experiments were carried out using an installation for arc welding in vacuum. Objects of research were metal cutting tools (lathe knives), made of high-speed steel HS6-5-2 on a base metal of structural steel C45. The structure, hardness and wear resistance after hardfacing and after a triple tempering at 560°C have been determined. The heat resistance of the obtained instruments has been examined. Findings: The microstructural analysis showed that the structure of the built-up layer consisted of martensite, retained austenite and carbides. This was confirmed by the values of measured hardness after welding which were about 63-64 HRC. The triple tempering led to an increase in hardness by 3-4 HRC. It was found that the built-up layers (cutting edges of tools) retain their hardness (HRC=63-65) up to a temperature of 615-620°C, which shows that the heat resistance of the build-up layers was similar to that of the hardened and tempered tools of the same steel. The built-up work-pieces (excluding heat treated) and the reference knife showed the same cutting qualities at cutting speeds in the range of 55 to 120 m/min. It has been found that triple tempering after hardfacing led to increased wear resistance and consequently the durability of the tool also increased due to the higher hardness. Practical implications: The practical application is related to the production of metalcutting tools. Originality/value: The proposed technological method allows to produce defects free built-up layers. The cutting properties of the built-up in vacuum layers are comparable to or better than those of new tools made of steel HS 6-5-2.

Active Control of Fuzzy for High-Speed Pantograph

2012 ◽  
Vol 251 ◽  
pp. 158-163 ◽  
Author(s):  
Gang Yang ◽  
Zhong Mei Dai ◽  
Fu Li ◽  
Zheng Zhi Luo
Keyword(s):  
Active Control ◽  
Contact Force ◽  
High Speed ◽  
Fuzzy Controller ◽  
Current Collection ◽  
Maximum Value ◽  
Dynamic Performances ◽  
Catenary System ◽  
The Impact

The regular current collection is very important for high-speed train， and can be obviously improved by the use of active control. In order to study the impact of the fuzzy active control on pantograph-catenary system, the model ohe simulation model is created with the software of simulink. Finally the influences of fuzzy active control on dynamic performances and quality of current collection of the pantograph-catenary system are analyzed. It seems that, the performances of the system with or without active control is established, the fuzzy controller is constructed, and tf the pantograph- catenary system can be improved obviously under the fuzzy active control, the maximum value of the contact force is reduced to 50 percent, the minimum is increased to 80 percent, and the fluctuation extent of the contact force is reduced to 70 percent.

scholarly journals Influence of Characteristics of the Melted Basalt on the Process of Formation of Fibers

2020 ◽  
Vol 6 (6) ◽  
pp. 15-24
Author(s):  
Zh. Aydaraliev ◽  
Yu. Ismanov ◽  
A. Kainazarov
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Viscosity Coefficient ◽  
Mineral Wool ◽  
Fiber Formation ◽  
Hydrodynamic Resistance ◽  
Hydrodynamic Characteristics ◽  
Mineral Fibers ◽  
The Relationship

In any production of products based on mineral fibers, one of the main types of equipment included in the line for the production of fiber products is installations for forming a basalt carpet, or the so-called fiberizing chambers. The quality of finished products depends on their perfection. Currently, there are several widely used in industry methods for producing mineral fibers from melt, which determine the various types and designs of fiberization chambers. In all chambers, the formation of mineral wool carpet occurs under the influence of hydrodynamic forces. Therefore, the study of such hydrodynamic characteristics as the rate of fall of individual fibers and clumps of these fibers and the hydrodynamic resistance of the carpet are of paramount importance in the design of new and reconstruction of old chambers. In this paper, we study the relationship between the strain rate and the viscosity coefficient of basaltic melt during fiber formation using a blow head developed by the authors. The substantiation of the process of fiber formation using a blowing head is given. Relations are obtained that establish the dependence of the strain rate in the fiber stream on the viscosity of the melt. Experimental data have been obtained that can be used to evaluate the effect of a basalt deposit on the dependence of the strain rate on the viscosity of a basalt melt. It was found that high-speed deformation of the melt greatly affects the quality of the fibers and the amount of waste in the production of fibers.

scholarly journals Automatic Pneumatic Sheet Metal Feeding and Cutting Machine

2021 ◽  
Vol 9 (11) ◽  
pp. 150-165
Author(s):  
Mr. Pratik Gujarathi
Keyword(s):  
Sheet Metal ◽  
High Speed ◽  
Metal Cutting ◽  
Control Valve ◽  
Everyday Objects ◽  
Cutting Machine ◽  
Long Time ◽  
High Production ◽  
Sheet Metal Cutting

Abstract: Today in the rapid competition of the industries to get the best quality of the product in the minimum required time is the main aim of industries. To get the best quality and maximum production most advanced machines are used. But there are no facts that use only the advanced machines, to maintain their performance is real requirement of the industries, also to give proper facilities to the workers with good environmental condition and to reduce their efforts is one of the objects to achieve the best quality and high production. Sheet metal is simply a metal formed into thin and flat pieces. It is one of the fundamental forms used in metal working and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of the material. Thicknesses can vary significantly, although extremely thin thicknesses are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate. Sheet metal also has applications in car bodies, airplane wings, medical tables, roofs for buildings (Architectural) and many other things. Sheet metal of iron and other materials with high magnetic permeability, also known as laminated steel cores, has applications in transformers and electric machines. There are three primary procedures in Layout. They are Parallel, Radial, and Triangulation. The major aim to our experiment is to study about pneumatic control system, study about double acting cylinder, study about the advantage of pneumatic hand operated valve and study about high speed blade. We are using scissors for simple sheet metal cutting. It is a manual method so that sheet metals are to be wasted sometimes because of mistakes happened such as wrong dimensions etc., and also even a simple cutting may take long time. We are using a pneumatic system for sheet metal cutting in an easy way. It is operated by a pneumatic hand lever of two ways control valve. Control valve is operated by a compressor. Keywords: Pneumatic, Automation, Sheet Metal, Pneumatic, Valve, Cutting Machine

Correlation of Flow Stress With Strain Rate and Temperature During Machining

1973 ◽  
Vol 95 (2) ◽  
pp. 94-98 ◽  
Author(s):  
J. A. Bailey ◽  
D. G. Bhanvadia
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Metal Cutting ◽  
Strain Rates ◽  
Rake Face ◽  
Rate Parameter ◽  
Idealized Model ◽  
Orthogonal Metal Cutting ◽  
Continuous Chip ◽  
Strain Rate Parameter

An idealized model of the orthogonal metal cutting process is used to determine the stresses, strain rates, and temperatures at the tool rake face for the machining of several materials under dry, unlubricated conditions, where a continuous chip is produced with an absence of a built-up edge. An attempt is made to correlate stress with strain rate and temperature using a temperature compensated strain rate parameter, and velocity modified temperature.

Sign in / Sign up

Export Citation Format

Share Document