scholarly journals New combined method of the thermoplastics turning

2021 ◽  
pp. 42-44
Author(s):  
O. Yu. Erenkov ◽  
E. V. Yavorskaya
Keyword(s):  
Experimental Studies ◽  
Vacuum Treatment ◽  
Work Piece ◽  
Combined Method ◽  
Machined Surface

The article presents the results of experimental studies of thermoplastic turning with the use of advancing vacuum treatment of the work piece surface. It has been experimentally proven that turning thermoplastics with advancing vacuum treatment of the surface of the work pieces leads to a better machined surface of the part in comparison with the traditional turning method.

scholarly journals Technological Features in Processing of Conical Lenses

2020 ◽  
Vol 19 (6) ◽  
pp. 521-527
Author(s):  
M. I. Filonova ◽  
R. O. Dias Gonzalez ◽  
A. A. Sukhotzkiy ◽  
A. S. Kozeruk ◽  
A. V. Semchuonok
Keyword(s):  
Glass Plate ◽  
Experimental Studies ◽  
Central Zone ◽  
Conical Surface ◽  
Work Piece ◽  
Cylindrical Shape ◽  
Cylindrical Blank ◽  
Machined Surface ◽  
Optimal Sequence ◽  
Plane Parallel

The paper presents the technology of obtaining flat-conical lenses (axicons) by the method of free grinding a work-piece to a flat tool through a layer of abrasive suspension. For this, theoretical and experimental studies of the regularities of stock removal from the base of the cone and its lateral surface have been carried out. The processing modes have been identified that ensure both uniform operation of the flat surface of  the part and enhanced removal of  the allowance in the edge or central zone of this surface. During the study of the processing of the conical surface, the set-up parameters of the technological equipment have been established, at which there is a minimum deviation of the generatrix of the cone from straightness and maximum productivity of the process. The stages of processing conical lenses are proposed, which allow to assign the optimal sequence of operations in the manufacture of this type of parts from blanks of a cylindrical shape in cases where  the ratio of the height of the cone to the diameter of its base H/d £ 0.5. The main stages of processing include: grinding of the bases of cylindrical blanks with maintaining their mutual parallelism with a given accuracy; polishing one of the cylinder bases to achieve the required roughness and deviation from non-flatness; fastening a cylindrical blank to an auxiliary plane-parallel glass plate using molecular cohesion forces; mechanical fastening of a cylindrical work-piece with a collet adapter mandrel for a plane-parallel glass plate; applying the nearest sphere to the second base of the cylindrical blank; drawing a conical surface on the spherical part of a plano-convex lens; grinding and polishing the conical surface to achieve the required roughness  and straightness of the cone generatrix. The degree of efficiency of the setup parameters of the machine has been revealed depending on the technological heredity of the work-piece from the point of view of the distribution of the allowance to be removed over the machined surface. 

Performance assessment of energy efficient and eco-friendly turning of Nimonic C-263: A comparative study on MQL and cryogenic machining

2021 ◽  
pp. 095440542110619
Author(s):  
Prashant S Jadhav ◽  
Chinmaya P Mohanty
Keyword(s):  
Work Environment ◽  
Manufacturing Industry ◽  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Work Piece ◽  
Cryogenic Machining ◽  
Machined Surface ◽  
Machining Strategies ◽  
The Impact

Nimonic C-263 is predominantly used in the manufacturing of heat susceptible intricate components in the gas turbine, aircraft, and automotive industries. Owing to its high strength, poor thermal conductivity, the superalloy is difficult to machine and causes rapid tool wear during conventional machining mode. Moreover, the unpleasant machining noise produced during machining severely disrupts the tool engineer’s concentration, thereby denying a precise and environment friendly machining operation. Hence, close dimensional accuracy, superior machined surface quality along with production economy, and pleasant work environment for the tool engineers is the need of an hour of the current manufacturing industry. To counter such issues, the present work attempts to compare and explore the machinability of two of the most popular machining strategies like minimum quantity lubrication (MQL) and cryogenic machining process during turning of Nimonic C-263 work piece in order to achieve an ideal machining environment. The machining characteristics are compared in terms of surface roughness (SR), power consumption (P), machining noise (S), nose wear (NW), and cutting forces (CF) to evaluate the impact of machining variables like cutting speed (Vc), feed (f), and depth of cut (ap) with a detailed parametric study and technical justification. Yet again, an investigation is conducted to compare both the machining strategies in terms of qualitative responses like chip morphology, total machining cost, and carbon emissions. The study revealed that cryogenic machining strategy is adequately proficient over MQL machining to deliver energy proficient and gratifying work environment for the tool engineers by reducing the cost of machining and improving their work efficiency.

Технологическое обеспечение качества поверхностного слоя стекловолоконных композитов при концевом фрезеровании

2020 ◽  
Vol 22 (4) ◽  
pp. 31-40
Author(s):  
Andrei Markov ◽  
◽  
Vyacheslav Nekrasov ◽  
Jian Su ◽  
Azhar Salman ◽  
...  
Keyword(s):  
Composite Materials ◽  
End Milling ◽  
Experimental Studies ◽  
Milling Process ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Scientific Publications ◽  
Experimental Assembly ◽  
Operation Results

Introduction. Today fiberglass is one of the most common composite materials. Therefore, its mechanical processing continues to be the subject of many studies. In many scientific publications, the influence of cutting modes and structural and geometric parameters of the tool on the roughness of the machined surface, cutting forces and wear of the cutting tool has been established. The purpose of this work is to study the effect of machining modes on delamination and roughness of fiberglass composites during end milling, as well as testing the hypothesis about the effect of torque on the delamination. The relevance of the study is due to the fact that delamination, along with roughness, has a significant impact on the quality of processing and subsequent assembly of the finished product. A criterion is proposed for assessing the magnitude of the delamination of composite materials during its machining. The results of experimental studies of the torque on the cutter, the relative coefficient of delamination and surface roughness from cutting conditions are presented. Methods: factorial experiment using an experimental assembly developed by the authors based on a piezoelectric torque sensor. The installation allows real-time recording of the change in torque during the milling process, depending on the modes of operation. Results and Discussion. A comparative analysis of the obtained dependences showed that the torque is directly related to delamination. To reduce the delamination, the depth of cut should be decreased, and in order to ensure the specified productivity, the feed and the rotational speed of the cutter should be increased. The presented results confirm the prospects of the developed approach aimed at machining new classes of composite materials.

DEVICE FOR HONING PLANES WEDGES VALVES ARTILLERY SYSTEMS

2020 ◽  
pp. 37-42
Author(s):  
V. A. Bahvalov
Keyword(s):  
Metal Removal ◽  
High Strength ◽  
Gear Ratio ◽  
Work Piece ◽  
Milling Machine ◽  
Machined Surface ◽  
Vertical Milling ◽  
Milling Machines ◽  
Vertical Milling Machine ◽  
Kinematic Diagram

The article describes the process of honing the details of command artillery systems, in particular the process of honing planes wedge gate of medium-caliber guns. The article is an analysis of the kinematic scheme of the device and the selected gear ratio device that provides even wear a uniform honing stones and metal removal with a flat machined surface of the work piece due to the commission of the cutting grains honing stones complex movements in the horizontal plane. Next each of the cutting grains will not be repeated for the entire processing cycle. Kinematic diagram of the device with the established and enshrined in the radial grooves of the disc honing stones is implemented in the design and manufacture of devices for honing on vertical milling machines planes wedge gate artillery systems. Investigation of the process of honing the flat specimens made of high-strength gun steels viscous with plan dimensions 130x240 mm possible to determine the rational parameters of flat honing process.Production testing device for honing planes wedge gate of one of the artillery pieces on a vertical milling machine performed at one of the engineering confirmed the efficiency of the device for a flat honing. Honing wedge planes shutter serial products (76 mm caliber gun) on a vertical milling machine using the apparatus discussed in the article improves the processing performance in comparison with conventional processing means 20…35 %. In this case, stability is regulated product design documentation form accuracy and size of the part and the surface roughness of the planes of the wedge gate Ra £ 0,32 microns.

Finite Element Modeling of Hard Roller Burnishing: An Analysis on the Effects of Process Parameters Upon Surface Finish and Residual Stresses

2007 ◽  
Vol 129 (4) ◽  
pp. 705-716 ◽  
Author(s):  
Partchapol Sartkulvanich ◽  
Taylan Altan ◽  
Francisco Jasso ◽  
Ciro Rodriguez
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Process Parameters ◽  
Surface Finish ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Cost Effective ◽  
Machined Surface ◽  
Fem Model ◽  
Roller Burnishing

Hard roller burnishing is a cost-effective finishing and surface enhancement process where a ceramic ball rolls on the machined surface to flatten the roughness peaks. The ball is supported and lubricated by hydrostatic fluid in a special tool holder. The process not only improves surface finish but also imposes favorable compressive residual stresses in functional surfaces, which can lead to long fatigue life. Most research in the past focused on experimental studies. There is still a special need for a reliable finite element method (FEM) model that provides a fundamental understanding of the process mechanics. In this study, two-dimensional (2D) and three-dimensional FEM models for hard roller burnishing were established. The developed 2D FEM model was used to study the effects of process parameters (i.e., burnishing pressure, feed rate) on surface finish and residual stresses. The simulation results were evaluated and compared to the experimental data. Results show that the established FEM model could predict the residual stresses and provided useful information for the effect of process parameters. Both FEM and experiments show that burnishing pressure is the most influence, where high burnishing pressure produces less roughness and more compressive residual stress at the surface.

scholarly journals INVESTIGATION INTO TT TECHNOLOGICAL PROPERTIES OF COOLANTS WITH LIQUID CRYSTAL ADDITIVES / TEPIMO IR AUŠINIMO SKYSČIO SU SKYSTŲJŲ KRISTALŲ PRIEDAIS TECHNOLOGINIŲ SAVYBIŲ TYRIMAS

2012 ◽  
Vol 3 (6) ◽  
pp. 71-74
Author(s):  
Vaidas Strolia ◽  
Vadim Mokšin ◽  
Robertas Urbanavičius
Keyword(s):  
Liquid Crystals ◽  
Comparative Research ◽  
Liquid Crystalline ◽  
Work Piece ◽  
Machined Surface ◽  
Mineral Oils ◽  
Twisted Nematic ◽  
Iron Work ◽  
Cutting Zone ◽  
Oil Emulsions

The paper presents the results of comparative research on the roughness and tool life of the machined surface when steel and cast iron work pieces were turned, reamed and tapped and the cutting zone was lubricated by various coolants (mineral oils, oil emulsions) with and without twisted nematic liquid crystals. The tested liquid crystals were taken from the same homologous series (fatty acid cholesterol esters) but had different molecular mass. It has been established that the most positive tribological effect of liquid crystalline additives is achieved when high-molecular liquid crystals are used in operations characterized by the largest tool-work piece interface area (reaming, threading). Santrauka Straipsnyje pateikti apdirbto paviršiaus šiurkštumo ir įrankių patvarumo matavimo rezultatai, kai plieno ir ketaus paviršiai buvo tekinami, plečiami ir sriegiami sriegikliais, pjovimo zoną tepant ir aušinant įvairiais tepimo ir aušinimo skysčiais su cholesterinių skystųjų kristalų priedais ir be priedų. Buvo naudojami skirtingos molekulinės masės vienos homologinės eilės cholesteriniai skystieji kristalai (cholesterolio esteriai) ir skirtingi tepimo ir aušinimo skysčiai: tepalai ir mineralinių tepalų vandens emulsijos. Nustatyta, kad didžiausias teigiamas skystųjų kristalų priedų efektas pasiekiamas tų operacijų metu, kai įrankio ir detalės kontakto plotas yra didesnis (pvz., plečiant, sriegiant). Taip pat nustatyta, kad didžiausiu tribologiniu efektu pasižymi didesnės molekulinės masės skystieji kristalai.

Exploration on Grinding Temperature Field Based on Water Vapor Cooling

2013 ◽  
Vol 820 ◽  
pp. 170-174
Author(s):  
Li Gang Zhao ◽  
Qing Ming Ding ◽  
Jia Long Ren
Keyword(s):  
Temperature Field ◽  
Water Vapor ◽  
Experimental Studies ◽  
Test Methods ◽  
Grinding Temperature ◽  
Machined Surface ◽  
Ansys Simulation ◽  
Dry Grinding ◽  
Grinding Temperature Field ◽  
Zone Temperature

To explore the influence of the water vapor cooling conditions on grinding temperature field of titanium alloy TC4 material, ANSYS simulation and test methods are adopted in this paper. Simulation and experimental studies show that: water vapor as coolant can reduce the surface temperature of the workpiece quickly by changing the wheel speed, workpiece speed and cutting depth; Water vapor cooling can control the grinding zone temperature below 400 °C on certain conditions, and compared with dry grinding it can reduce more than 50%; The grinding zone temperature can significantly be reduced by optimizing the grinding process parameters and improving the quality of the machined surface.

Non-Destructive Inspection of Surface Integrity in Milled Turbine Blades of Inconel 738LC

2013 ◽  
Vol 486 ◽  
pp. 9-15 ◽  
Author(s):  
Kamil Kolařík ◽  
Zdenek Pala ◽  
Libor Beranek ◽  
Jiří Čapek ◽  
Zdenek Vyskocil ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Surface Integrity ◽  
Turbine Blades ◽  
Mutual Effect ◽  
Work Piece ◽  
Machined Surface ◽  
Grain Sizes ◽  
Cutter Orientation ◽  
Inconel 738Lc ◽  
Non Destructive

Nickel super-alloys are widely used in aerospace as material for turbine blades. Unfortunately, their machining is difficult since mechanical hardening and, consequently, extreme tool wear occur. Casting can no longer meet the requirements for precision, hence, the castings are being ground or milled. In this contribution, a quality check of the milled surface by several surface integrity parameters is proposed with respect to the surface structural inhomogeneities caused by mutual effect of plastic deformations and thermal fields during the cutting process. Castings from Inconel 738LC were milled with cutting conditions chosen by Design-Of-Experiments method and the resulting surfaces were assessed by non-destructive X-ray diffraction methods in several areas corresponding to various cutter orientation and work-piece angle. Surface integrity was described by macroscopic residual stresses, microstrains, grain sizes and phase composition. Mostly, favourable compressive surface residual stresses were observed in the cutting direction, grain sizes were distinctively smaller when the tool axis was perpendicular to the machined surface.

Determination of Turning Knife Thermal Stress during Longitudinal Turning

2016 ◽  
Vol 821 ◽  
pp. 649-654
Author(s):  
Marek Stránský ◽  
Jaroslav Horský
Keyword(s):  
Machine Tools ◽  
Inverse Relationship ◽  
Work Piece ◽  
Machined Surface ◽  
One Dimensional ◽  
Friction Heat ◽  
Longitudinal Turning ◽  
New Machine

A turning knife contacts a work piece during turning. Due to friction, heat is produced proportionally to the turning speed. The resulting temperature influences the quality of the machined surface and wear of the knife. Thus, new machine tools must be developed that minimize the production of unwanted heat. To accomplish this task, a new experimental knife was prepared with thermocouples both built into it and welded to its surface. The measurement process was supplemented by thermovision. Heat flux and surface temperatures were computed from subsurface data using a one-dimensional inverse relationship. The detailed temperature distribution on the surface of the turning knife was determined using a combination of these methods.

scholarly journals Effect of the lead angle and the radius of curvature on the cutting forces in a 5-axis milling of sculptured surfaces

Mechanik ◽  
2018 ◽  
Vol 91 (1) ◽  
pp. 18-22
Author(s):  
Michał Gdula ◽  
Jan Burek
Keyword(s):  
Turbine Blade ◽  
Convex Surface ◽  
Experimental Studies ◽  
Surface Profile ◽  
Radius Of Curvature ◽  
Sculptured Surface ◽  
Sculptured Surfaces ◽  
Inconel 718 Alloy ◽  
Machined Surface ◽  
Lead Angle

Experimental studies are presented, were conducted that aimed at determining the mathematical models of the influence of the lead angle and the radius of curvature of the profile of machined sculptured surface on the components of the cutting force. The object of the experimental studies was a convex and concave surface of a turbine blade of Inconel 718 alloy. The toroid cutter was used for the tests. Based on the results of the study it was found that the lead angle in the machining of the convex surface and concave turbine blade should be continuously varied with the change of radius of curvature in the direction of the machined surface profile.

Sign in / Sign up

Export Citation Format

Share Document