Thermal Analysis of the Wear of Single Abrasive Grains

1974 ◽  
Vol 96 (4) ◽  
pp. 1245-1252 ◽  
Author(s):  
R. F. Scrutton ◽  
G. K. Lal

It is shown that the wear of single abrasive grains in a simulated grinding operation (over-cut fly milling) is governed by a thermally activated mechanism. The model adopted in this theoretical treatment assumes that most of the energy expended during grinding enters the workpiece via adiabatic plastic flow. The accompanying rise in temperature at the grain-workpiece interface decreases the shear flow stress of the softer metal. This permits a greater adhesive wear rate. The predictions of the theory agree with the results of extensive experimental data.

1993 ◽  
Vol 115 (2) ◽  
pp. 453-460 ◽  
Author(s):  
Hui Zhang ◽  
M. Karim Moallemi ◽  
Sunil Kumar

In this study a thermal analysis is performed on the hot dip-coating process where solidification of metal occurs on a bar moving through a finite molten bath. A continuum model is considered that accounts for important transport mechanisms such as axial heat diffusion, buoyancy, and shear-induced melt motion in the bath. A numerical solution procedure is developed, and its predictions are compared with those of an analytical approximate solution, as well as available experimental data. The predictions of the numerical scheme are in good agreement with the experimental data. The results of the approximate solution, however, exhibit significant disagreement with the data, which is attributed to the simplifying assumptions used in its development. Parametric effects of the bath geometry, and initial and boundary temperatures and solid velocity, as characterized by the Reynolds number, Grashof number, and Stefan numbers, are presented.


2010 ◽  
Vol 7 (1) ◽  
pp. 227-233

This is about synthesizing new complex combinations of Cu(II), Ni(II),Co(II), Zn(II) with aroylhydrazone ligand isonicotinoylhydrazone-2-aldehydefluorene (INHAF) made by condensation of isonicotinoylhydrazine with 2-aldehydefluorene. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility values, thermal analysis and for the Cu(II) complex the ESR spectrum has been registered. For all complexes the biological activity against theStaphylo-coccus aureus, Escherichia coli, Klebssiella pneumoniaebacteria has been investigated. The experimental data sustain stoichiometry of 1:2 (metal/ligand) for the Cu(II), Ni(II), Zn(II) complexes and of 1:1 for the complex with Co(II). The electronic spectra and the magnetic moments suggest octahedral stereochemistry at the complexes with Cu(II), Ni(II) and the tetrahedral geometry for the Co(II) complex. The INHAF ligand is coordinated bidentate by the O=C amide oxygen and the azomethine nitrogen in the complexes of Cu(II), Ni(II), Co(II) and monodentate by the azomethine nitrogen in the complex of Zn(II).


1959 ◽  
Vol 37 (4) ◽  
pp. 737-743 ◽  
Author(s):  
Ludovic Ouellet ◽  
James A. Stewart

A theoretical treatment is worked out for the kinetic scheme[Formula: see text]in which the concentration of P1 is followed. The steady-state and transient phase equations are obtained subject to the condition that the substrate concentration is greatly in excess of the enzyme concentration. The conditions under which evidence in favor of this mechanism can be obtained from experimental data are discussed. Under certain conditions, the weight of the enzyme corresponding to one active site can be determined. Methods for the evaluation of the different constants are described.


2020 ◽  
Vol 2 ◽  
pp. 295
Author(s):  
C. T. Papadopoulos ◽  
R. Vlastou

Recent advances in the physics of nuclei at high spin are presented. In particular the new phenomena observed by the latest generation of γ-rays spectrometers are discussed. An overview of experimental and theoretical treatment of "backbending·'' effect, quasiparticle alignment and band crossing is described in more detail. The outlines of the Cranked Shell Model, which is a successful framework for the interpretation of experimental data, are also reported.


2021 ◽  
Author(s):  
Khaled Boughzala ◽  
Mustapha Hidouri

Waste regenerated after washing of rock phosphate and phosphogypsum has been proposed as removal agents of Acid Red 88 (AR 88)) from artificially contaminated solution. Natural phosphate (PN) was also studied for comparison. These materials were characterized beforehand, as is intended for the removal tests, by chemical analysis, powder X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis– differential thermal analysis, scanning electron microscopy, and N2 adsorption isotherms. The conducted experiments show that among the different materials, the PWR has the highest retention capacity of the dye (123.4 mg g−1) of AR-88. Upon calcinations, the removal capacities reduced by 60 to 70%. We take note also that a decrease in the amount of removed AR 88 dye occurs with an increase in pH. The kinetics data on the reaction between AR 88 and the materials are described well by a pseudo -second-order model. The Langmuir model is successfully applied to the experimental data of the removal of acid red 88. The removal process is exothermic.


2009 ◽  
Vol 16-19 ◽  
pp. 1258-1262
Author(s):  
Yun Feng Zhang ◽  
Zhi Li Sun

Metal- matrix composites layers were prepared by laser cladding with Ni-based Super-alloy onto CrMo cast iron. Applying uniform experiment design, under conditions of different velocity and load ,the wear tests of alloy layers were carried out and the stepwise regression method are used to establish the wear rate model for prediction of wear rate. It is proved that the modal is significant and represents the character of the wear trend. According to the wear rate model ,the wear characteristics are analysed and the wear mechanisms are identified. The main wear mechanism of laser cladding layer are delamination, adhesive wear and abrasive wear.


1966 ◽  
Vol 39 (5) ◽  
pp. 1489-1495
Author(s):  
L. C. Case ◽  
R. V. Wargin

Abstract A new theoretical treatment strongly indicates that an elastomer network actually consists of a system of fused, closed, interpenetrating loops of polymer chains. This interpenetrating loop structure restricts the movement of the chains and thereby affects the stress-strain behavior of the elastomer. Methods have been developed to enable the calculation of the number of effective crosslinks caused by loop interpenetrations (virtual crosslinks). The uniaxial stress-strain behavior of an elastomer predicted using our methods can be fitted almost perfectly to published experimental data by proper selection of chain parameters. Previous theoretical treatments gave only a qualitative fit to the experimental data for the stress-strain behavior of elastomers and were not capable of predicting the correct shape of the experimental stress-strain curve. The present treatment gives a nearly perfect fit for both stress as a function of strain at constant crosslink density, and stress as a function of crosslink density at constant strain, and thus represents a vast improvement.


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