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

Author(s):  
Yu. M. Zubarev ◽  
A. V. Priemyshev

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.

Author(s):  
Yu. M. Zubarev ◽  
A. V. Priemyshev

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.


Author(s):  
Yu. M. Zubarev ◽  
A. V. Priemyshev

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.


2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.


Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 846-849
Author(s):  
Elżbieta Bączek

Metal matrix composites were prepared by hot pressing (HP) and spark plasma sintering (SPS) techniques. Ball-milled ironbase powders were consolidated to near full density by these methods at 900°C. The physical and mechanical properties of the resulting composites were investigated. The specimens were tested for resistance to both 3-body and 2-body abrasion. The composites obtained by HP method (at 900°C/35 MPa) had higher density, hardness and resistance to abrasion than those obtained by SPS method.


2020 ◽  
Vol 14 (2) ◽  
pp. 117-124
Author(s):  
Bayu Rahmat Saputro ◽  
Amin Suhadi

Abstract A research was conducted on the grinding process of ferrite magnet with Strontium ferrite type (SrO.6 (Fe2O3)) using electroplated single layer grinding wheels. Many cracks have been found on work pieces during this work, which is coming from grinding processes. Research is conducted starting from chemical composition test and the effect of the shape and size of the abrasive grain of grinding wheels to the quality of grinding process results by measuring crack ratio of the work piece.  In this experiment, 3 (three) model design of grinding wheels with three different size and shape of abrasive grains are made. All of processing parameters are set at the same value as ordinary process.  The experimental results shown that 3rd model have the best results from the outputs number and also the lowest reject crack ratio compared to 1st and 2nd models. This is because the 3rd model has blocky shape which its distribution structure is denser and more uniform compared to the irregular shape, so that continuous grinding on hard and brittle work pieces is more stable and suitable


2012 ◽  
Vol 503-504 ◽  
pp. 74-77
Author(s):  
Nan Hu ◽  
Xian Jun Li ◽  
Yi Qiang Wu ◽  
Xin Gong Li ◽  
Zhi Cheng Xue

In this paper, the new bamboo-based consolidated composite floors were fabricated with thin bamboo veneers which used as decoration layers, wear resistant layers, high density fiberboards and equilibrium layers through assembling and scuffing. The effect rules of the composite floor on properties were preliminarily studied by three factors: hot-pressing temperature, pressure and time. The results showed that the wear resistance and surface bond strength of the thin bamboo veneer consolidated composite floor significantly increased with the rise of hot-pressing temperature. In the scope of resources, the effect of hot-pressing pressure and time on properties of the floor is not significant. The optimizing technology is hot-pressing temperature 170°C, pressure 3MPa and time 40s/mm in this study. The thin bamboo veneer consolidated composite floor is an excellent floor decorative material, which has good physical and mechanical properties.


2005 ◽  
Vol 297-300 ◽  
pp. 2813-2818 ◽  
Author(s):  
Xun Cai ◽  
Xiaoyu Yang ◽  
Tao Zhao ◽  
Liuhe Li ◽  
Qiu Long Chen

The mixture of Ni based alloy powder and WC particles were used as a feeding material to modify the surface properties of cast Al-Si alloy using a CO2 continuous transverse flow laser beam with maximum power of 10 kW. Microstructures and chemical components of the laser surface cladding (LSC) layers were studied using SEM, XRD, TEM and EDS. It is shown that the LSC layers were composed of γ-( Ni, Cr, Fe, W)matrix phase and many enhancing phases, such as Ni2Al3, Ni3Al, WC, W2C, Cr2B, etc.. The microstructure of the LSC layers was greatly affected by the scanning rate b V and the powder of feeding rate p m under the same laser power. With the increasing of b V and p m , the dissolution phenomenon of WC particles was improved; the length, the diameter and the amount of the acicular constituent were markedly reduced. Microhardness and wear resistance tests were also performed: the average microhardness of the LSC layers was around 5.1 to 5.9GPa, which was five times higher than that of the Al-Si substrate. The wear resistance of the layer was about 20 times as big as that of cast Al-Si alloy when P=6kW, b V =13.3mm s-1, p m =100mg s-1, L=500N. The results showed that the mechanical properties of LSC layers on cast Al-Si alloy can be markedly enhanced with proper processing parameters. However, due to the sudden change of physical and mechanical properties between laser modified layer and substrate, some defects, especially crack, actually occur in the surface modified layer and the interface zone. And finally Ni/WC surface gradient layer was obtained on cast Al-Si alloy through thrice laser scanning technique. The microhardness of the laser gradient layer gradually changed from surface to substrate, so that it can reduce stress concentration in the whole laser surface layer, especially in the interface zone.


2017 ◽  
Vol 907 ◽  
pp. 3-7
Author(s):  
Hülya Akkan ◽  
Mehmet Şi̇mşi̇r ◽  
Kerim Emre Öksüz

NiTi shape memory alloys have attracted significant interest due to their unique superelasticity and high damping performance. In this work, the effect of SiC particle size on both physical and mechanical properties of NiTi matrix composite was investigated. Ni and Ti powders with particle sizes of 40 µm were used with the SiC addition with varying particle sizes of 20 µm and 40 µm, respectively. Composites of NiTi with 1wt. % SiC were fabricated by powder metallurgy technique. The effects of SiCp addition on hardness, relative density and wear behavior of NiTi composites have been investigated. The samples were examined by scanning electron microscope, for microstructural studies and phase development. The results showed that the distribution of the reinforced particle was uniform. Moreover, as the SiC particle size decreases, hardness and wear resistance increase. It was demonstrated that SiC particle size significantly enhanced the wear resistance of NiTi composite.


2021 ◽  
Vol 7 (2(38)) ◽  
pp. 31-32
Author(s):  
G. A. Zharmagambetova ◽  
I. A. Kudusova ◽  
V. Ch. Laurinas

A number of experiments were conducted to measure the physical and mechanical properties of multielement coatings. To apply CrNiTiFeCu coatings on a nickel-chromium substrate, the technology of magnetron deposition in an atmosphere of argon or nitrogen was used. The results of measurements of the microhardness as well as the coefficients of friction and wear resistance of the applied CrNiTiFeCu thin films are presented. The findings indicate that the studied samples show a high microhardness and wear resistance. Consequently, there is a possibility to extend the lifespan of mechanisms and machines parts.


2016 ◽  
Vol 17 (4) ◽  
pp. 611-620
Author(s):  
H.O. Sirenko ◽  
L.M. Soltys ◽  
V.P. Svidersky ◽  
I.V. Sulyma

The resultsof studies of the effect of nature and parameters of particle size distribution of graphite on physical and mechanical properties of polymer composites based on aromatic polyamide fenіlon C-2. The particle size of the filler and polymer for the theoretical gamma-distribution parameters (perimeter, thickness and diameter) have different values. Found the influence of fillers (natural graphite different bands), which differed ash content (5-15% and 0,05-2,5%), moisture and grinding fineness (dispersion) on the wear resistance of the samples of the polymer composite. There is non-linear connectionbetween the intensity and parameters graphite particles distribution.


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