MODELING OF THE GRINDING PROCESS BY MICRO-CUTTING SINGLE ABRASIVE GRAINS. PART 3. FORMATION OF RIS-GROOVES

2021 ◽  
pp. 10-14
Author(s):  
Yu. M. Zubarev ◽  
A. V. Priemyshev
Keyword(s):  
Cutting Speed ◽  
Physical And Mechanical Properties ◽  
Metal Quality ◽  
Micro Cutting ◽  
Abrasive Grains ◽  
Wide Range ◽  
Machine Parts ◽  
Positive Effect ◽  
Cutting Speeds

When grinding on the processed surface of the workpieces of machine parts, a set of RIS-grooves is formed from the action of the vertices of the cutting abrasive grains of the circle. These risks mainly determine the roughness parameters of the treated surface and its physical and mechanical properties. The article presents the results of research of the micro-cutting process of different steels with different abrasive grains in a wide range of cutting speeds. It is shown that increasing the cutting speed during grinding has a positive effect on improving the metal quality of the surface layer of parts.

MODELING OF THE GRINDING PROCESS BY MICRO-CUTTING SINGLE ABRASIVE GRAINS. PART 1. DETERMINATION OF THE STRENGTH OF ABRASIVE GRAINS

2020 ◽  
pp. 13-17
Author(s):  
Yu. M. Zubarev ◽  
A. V. Priemyshev
Keyword(s):  
Cutting Speed ◽  
Tool Material ◽  
Physical And Mechanical Properties ◽  
Workpiece Material ◽  
Micro Cutting ◽  
Abrasive Grains ◽  
Maximum Cut ◽  
Wide Range ◽  
Cutting Speeds

Main performance indicators of grinding wheels are the strength and wear resistance of abrasive grains. The description of the installation for studying the process of micro-cutting of various materials with single abrasive grains, which allows you to approximate the working conditions of a single abrasive grain to the conditions of real grinding in a wide range of cutting speeds. The effect of the cutting speed on the maximum cut thickness maintained by the grain vertexes without their destruction is shown. The influence of physical and mechanical properties of the workpiece material and the abrasive tool material, together with technological factors, on the micro-cutting process is considered.

MODELING OF THE GRINDING PROCESS BY MICRO-CUTTING SINGLE ABRASIVE GRAINS. PART 2. WEAR ASSESSMENT OF ABRASIVE GRAINS

2021 ◽  
pp. 10-16
Author(s):  
Yu. M. Zubarev ◽  
A. V. Priemyshev
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Performance Indicators ◽  
Cutting Speed ◽  
Physical And Mechanical Properties ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Micro Cutting ◽  
Technological Factors ◽  
Abrasive Grains

One of the main performance indicators of grinding wheels is their wear resistance, which is largely determined by the wear resistance of abrasive grains. Data on the influence of physical and mechanical properties of the material of blanks and the material of abrasive grains, together with technological factors, on the micro-cutting process are presented. The influence of the cutting speed on the intensity and character of wear of abrasive grains is shown.

Thermal hardening and calculation of the mathematical model of face milling of parts made of steel 95X18-Sh to improve the quality of the surface layer

2021 ◽  
pp. 200-206
Author(s):  
I.N. Sedinin ◽  
V.F. Makarov
Keyword(s):  
Mathematical Model ◽  
Cutting Speed ◽  
Physical And Mechanical Properties ◽  
Face Milling ◽  
Experiment Planning ◽  
Depth Of Cut ◽  
Machined Surface ◽  
The Mathematical Model ◽  
Full Factorial

It is considered the complex of operations of the technological process for the heat treatment of steel 95X18-Sh, as a result of which the material of the samples increases the hardness to 59...61 HRC, and also improves the physical and mechanical properties. A full-scale full factorial experiment of face milling of samples was carried out using the method of mathematical planning. In the experiments, a high-precision machine and a carbide cutting tool were used. To calculate the values of the roughness function, the following are taken as independent variables: cutting speed, feed per tooth and depth of cut. In order to determine the coefficients of the linear equation, a central compositional orthogonal plan of the second order for three factors was used. A matrix of levels of variation of independent variable factors and a matrix of experiment planning were compiled. A regression analysis of the obtained experimental statistical data was carried out using the Microsoft Excel, Statistica and Wolfram Alpha programs. As a result of the calculations, a mathematical model of the roughness of the machined surface and optimal cutting conditions were determined.

scholarly journals The examination of the effect of variable cutting speeds on the surface and edge qualities of milled granite materials

2019 ◽  
Vol 11 (7) ◽  
pp. 168781401983631 ◽  
Author(s):  
István Gábor Gyurika ◽  
Tibor Szalay
Keyword(s):  
Surface Roughness ◽  
Cutting Speed ◽  
Sample Surface ◽  
Average Surface Roughness ◽  
Edge Chipping ◽  
Average Surface ◽  
Grain Sizes ◽  
Natural Stones ◽  
Cutting Speeds

Automated stone manufacturing has undergone considerable development in recent years. Thanks to international research dealing with the cutting, sawing and grinding of different natural stones, processing time shortens and tool-life lengthens. However, the process of stone milling has not been extensively examined yet, primarily because of the novelty of this technology. The aim of the research described in this article is to examine how variable cutting speed affects the quality of workpiece edges while milling granite materials. For the research, sample surfaces were formed on five granite slabs with different average grain sizes using five cutting speed values. Afterwards, changes in the average surface roughness and average edge chipping rate were examined. From the research results, it can be concluded that, due to an increase in cutting speed, the average edge chipping rate will decrease until reaching a borderline speed. In the case of a higher cutting speed, the referent tendency cannot be ascertained. A statistical analysis conducted in the scope of this research showed that if a variable cutting speed is applied, then changes in the quality of the sample surface edge can be inferred from the development trends of average surface roughness.

scholarly journals Deformation Structures and Tool Wear during High-Speed Machining

2013 ◽  
Vol 10 (1) ◽  
pp. 12-17
Author(s):  
Karol Vasilko
Keyword(s):  
High Speed ◽  
Cutting Speed ◽  
Tool Material ◽  
Machining Process ◽  
Surface Dynamics ◽  
Machined Surface ◽  
Deformation Structures ◽  
Cutting Speeds ◽  
Tool Durability

Abstract Tendencies towards increasing cutting speeds during machining can be observed recently. The first wave of increasing cutting speeds occured in the 60s of the previous century. However, suitable tool material was not available at that time. Increasing cutting speed is possible only following the development of cutting material, resistant against high temperatures, abrasive, adhesive and diffusive wear. It is obvious that the process of chip creation, quality of machined surface, dynamics of machining process and temperature of cutting change considerably with cutting speed. To be able to apply higher cutting speeds in production machining, it is necessary to know the dependence of those characteristics on cutting speed. Some of those phenomena, which are linked with cutting speed, will be explained in the paper. Key words: machining, cutting speed, tool durability, surface quality

scholarly journals Surface texture after finishing turning of AISI 630 martensitic steel

Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 865-867
Author(s):  
Kamil Leksycki ◽  
Eugene Feldshtein
Keyword(s):  
Surface Texture ◽  
Feed Rate ◽  
Martensitic Steel ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cooling Conditions ◽  
Dry Conditions ◽  
Psi Method ◽  
Positive Effect ◽  
Cutting Speeds

The surface texture of martensitic AISI 630 steel after the finishing turning is described. The tests were carried out under dry and cooling conditions. Experiments were carried out under variable cutting speeds and feeds and under a constant depth of cut. The Parameter Space Investigation (PSI) method was used that allows research with minimal experience point quantity. It was found that turning with cooling conditions reduce both Ra and Rq values and intensities of cutting speed and feed rate influence as compared out under dry conditions. The use of low feed rate values has a positive effect of the Ra and Rq parameters.

Experimental and Numerical Investigation of the Influence of Cutting Speed and Feed Rate on Forces in Turning of Steel

2016 ◽  
Vol 862 ◽  
pp. 270-277 ◽  
Author(s):  
János Kundrák ◽  
Gergely Szabó ◽  
Angelos P. Markopoulos
Keyword(s):  
Finite Elements ◽  
Feed Rate ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Strain Rates ◽  
Wide Range ◽  
Speed Range ◽  
The Impact ◽  
Cutting Speeds

The impact of cutting speeds and feed rates on the components of the forces exerted on a 16MnCr5 steel workpiece is experimentally measured, when turning with PCBN tool. The cutting speed range of the tests varies between 90 to 240 m/min while the feed rate is between 0.05 and 0.25 mm/rev for each cutting speed, allowing for the determination of the influence of cutting conditions on forces. Additionally, finite elements models for the simulation of the aforementioned experiments are provided. The proposed models exhibit good correlation of their results on cutting forces and chip formation with the measurements and observations of the experiments. Furthermore, the models can provide a wide range of additional parameters, i.e. plastic strain rates and temperatures within the workpiece. Results of the presented analysis can be used for an efficient process planning for the turning of steels under cutting conditions used in the industry.

The Crevoladossola marble (Piedmont, northern Italy): nine commercial varieties in just one quarry!

2021 ◽  
Author(s):  
Alessandro Cavallo ◽  
Giovanna Antonella Dino
Keyword(s):  
Physical And Mechanical Properties ◽  
Northern Italy ◽  
Dimension Stone ◽  
Stone Extraction ◽  
Extraction Technology ◽  
Fine Grain ◽  
Wide Range ◽  
Main Representative ◽  
Exemplary Model

<p>The Ossola valley (central Alps, northern Italy) is well known to produce a wide range of dimension stones: granites, gneisses, marbles and soapstones. The calcitic Candoglia marble is well-known because it was used in the cathedral of Milan, whereas the dolomitic Crevoladossola marble is widely spread and appreciated on the market. This work focusses on the varieties of the latter, the Crevoladossola marble: it pertains to the Mesozoic metasedimentary cover that tectonically separates the Monte Leone and Antigorio nappes (lower Penninic Units), with a quite steep structural setting and multiphase folding. The location of the quarry (Lorgino di Crevoladossola) is the same of the historic Pavia quarry of the «<em>Fabbriceria del Duomo di Pavia</em>», at the beginning of the 16th century. At present time there is only one active quarry which produces nine commerciali varieties: among these, <em>Palissandro Bluette</em>, <em>Palissandro Blu Nuvolato</em>, <em>Palissandro Classico</em> and <em>Palissandro Oniciato</em> are the most common ones. The quarry front is terraced and the extraction technology only uses diamond wire technology; the large extracted blocks are then selected based on their dimension, textural and chromatic features. The Crevoladossola marble (dolomite content 75 – 90% wt.)  has fine grain size and variable colour and texture due to the different amount of phlogopite (10 – 25% wt.) which defines the foliation plane, characterized by abundant isoclinal folds; there are also smaller amounts of quartz, anorthite, chlorite, tremolite, and rare disseminated sulphides. The presence of tremolite initially created doubts about the possible presence of asbestiform phases, however in-depth SEM-EDS analytical investigations excluded the presence of fibers, showing only cleavage fragments or prismatic - acicular crystals. With respect to the Candoglia and Ornavasso marbles, the Crevoladossola marble has markedly anisotropic physical and mechanical properties. In the Archaeological Museum of Milano possibly there is the first evidence of the use of this type of marble, represented by a sculpture of a Roman person (T. Labieno). Since 13th and 14th centuries this material was widely utilized in the local architecture of Domodossola, Baceno and Montecrestese, whereas its use was scarce in Lombardy: the main representative buildings are <em>Arco della Pace</em> in Milano with eight monolithic marble columns (10 m height) and the <em>Duomo</em> in Pavia (since 14th century). The marble is now used for internal facing, furnishings and valuable objects: in 1995 a block of <em>Palissandro Classico</em> was worked to produce the significant sculpture «<em>Uovo della Pace</em>» for UNICEF. The overall good quality of the rock mass and a rational exploitation make this quarry an exemplary model of dimension stone extraction; at the present time, efforts are also being made to exploit production waste, from crushed stone up to sawing sludge.</p>

scholarly journals A New Cutting Device Design to Study the Orthogonal Cutting of CFRP Laminates at Different Cutting Speeds

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4074 ◽  
Author(s):  
Víctor Criado ◽  
Norberto Feito ◽  
José Luis Cantero Guisández ◽  
José Díaz-Álvarez
Keyword(s):  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Linear Displacement ◽  
Tool Geometry ◽  
Cfrp Laminates ◽  
Reinforced Plastics ◽  
Wide Range ◽  
Cutting Speeds

Carbon Fiber-reinforced plastics (CFRPs) are widely used in the aerospace industry due to their highly mechanical properties and low density. Most of these materials are used in high-risk structures, where the damage caused by machining must be controlled and minimized. The optimization of these processes is still a challenge in the industry. In this work, a special cutting device, which allows for orthogonal cutting tests, with a linear displacement at a wide range of constant cutting speeds, has been developed by the authors. This paper describes the developed cutting device and its application to analyze the influence of tool geometry and cutting parameters on the material damage caused by the orthogonal cutting of a thick multidirectional CFRP laminate. The results show that a more robust geometry (higher cutting edge radius and lower rake angle) and higher feed cause an increase in the thrust force of a cutting tool, causing burrs and delamination damage. By reducing the cutting speed, the components with a higher machining force were also observed to have less surface integrity control.

scholarly journals Effects of Silica Nanoparticle Addition on Physical and Mechanical properties of Sugar Palm Fibers Reinforced Cement Composite Concrete

2020 ◽  
Vol 1 (1) ◽  
pp. 24
Author(s):  
Bintoro Siswo Nugroho ◽  
Yoga Pebrianto ◽  
Irfana Diah Faryuni ◽  
Asifa Asri
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Silica Nanoparticle ◽  
Cement Composite ◽  
Nano Silica ◽  
Water Testing ◽  
The Matrix ◽  
Reinforced Cement ◽  
Positive Effect

This study examines the effect of nanosilica addition to the physical and mechanical properties of sugar palm fibers (SPFs) reinforced cement composite concrete. The composite concrete ingredients are SPFs as the filler, cement and nano-silica as the matrix, CaCl2 as the catalyst, and water. Testing and fabrication of the composite concrete were performed according to the standard of ASTM C 1185 and ASTM C 1186. The results obtained show that, in general, the addition of nanosilica improves the quality of the composite concrete. A positive effect is attained by adding nanosilica to its optimum amount. The excessive addition of nanosilica reduces the quality of the composite. The composite's mechanical property that is negatively affected by the addition of the nanosilica is the elasticity, in which more nanosilica added stiffer the composite.

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