Modelling of the Mechanical State of a Diamond Particle in the Metallic Matrix

2014 ◽  
Vol 874 ◽  
pp. 127-132 ◽  
Author(s):  
Joanna Borowiecka-Jamrozek ◽  
Jan Lachowski
Keyword(s):  
Hot Pressing ◽  
Diamond Particle ◽  
Metallic Matrix ◽  
Mechanical State ◽  
Retention Efficiency ◽  
Iron Powders ◽  
Matrix Potential ◽  
The Matrix ◽  
Diamond Retention ◽  
Elastic And Plastic Deformation

The paper is concerned with the modelling of diamond retention efficiency of three different matrix materials: cobalt (EF), cobalt (SMS) and carbonyl iron powders. After the consolidation stage, the specimens were tested for tensile properties. The mechanical fields around a diamond particle were determined using computer simulations. The simulations were performed for a protruding diamond particle after hot pressing and after loading with an external force. The diamond retention efficiency of the matrix is affected by the interactions between the diamond crystal and the matrix during hot pressing. It is assumed that the matrix potential for diamond retention is associated with the amount of elastic and plastic deformation energies. The mechanical state generated in the matrix was calculated using Abaqus software.

scholarly journals Numerical Modelling of Stress/Strain Field Arising in Diamond-Impregnated Cobalt

2014 ◽  
Vol 59 (2) ◽  
pp. 443-446 ◽  
Author(s):  
J. Borowiecka-Jamrozek ◽  
J. Lachowski
Keyword(s):  
Strain Field ◽  
Diamond Crystal ◽  
Metallic Matrix ◽  
Stress And Strain ◽  
Stress Strain ◽  
Strain Fields ◽  
Matrix Potential ◽  
The Matrix ◽  
Saw Blade ◽  
Diamond Retention

Abstract The paper presents results of computer simulations of the stress/strain field built up in a cobalt matrix diamond impregnated saw blade segment during its fabrication and after loading the protruding diamond with an external force. The main objective of this work was to create better understanding of the factors affecting retention of diamond particles in a metallic matrix of saw blade segments, which are produced by means of the powder metallurgy technology. The effective use of diamond impregnated tools strongly depends on mechanical and tribological properties of the matrix, which has to hold the diamond grits firmly. The diamond retention capability of the matrix is affected in a complex manner by chemical or mechanical interactions between the diamond crystal and the matrix during the segment manufacture. Due to the difference between the thermal expansion coefficients of the diamond and metallic matrix, a complex stress/strain field is generated in the matrix surrounding each diamond crystal. It is assumed that the matrix potential for diamond retention can be associated with the amount of the elastic and plastic deformation energy and the size of the deformation zone occurring in the matrix around diamonds. The stress and strain fields generated in the matrix were calculated using the Abaqus software. It was found that the stress and strain fields generated during segment fabrication change to a large extent as the diamond crystal emerges from the cobalt matrix to reach its working height of protrusion.

scholarly journals An Analysis of the Retention of a Diamond Particle in a Metallic Matrix after Hot Pressing

2017 ◽  
Vol 17 (1) ◽  
pp. 17-20 ◽  
Author(s):  
J. Borowiecka-Jamrozek ◽  
J. Lachowski
Keyword(s):  
Elastic Energy ◽  
Synthetic Diamond ◽  
Computer Modelling ◽  
Diamond Particle ◽  
Metallic Matrix ◽  
Mechanical Parameters ◽  
Powder Mixtures ◽  
The Matrix ◽  
Calculation Results ◽  
Abaqus Software

Abstract This paper deals with computer modelling of the retention of a synthetic diamond particle in a metallic matrix produced by powder metallurgy. The analyzed sintered powders can be used as matrices for diamond impregnated tools. First, the behaviour of sintered cobalt powder was analyzed. The model of a diamond particle embedded in a metallic matrix was created using Abaqus software. The preliminary analysis was performed to determine the mechanical parameters that are independent of the shape of the crystal. The calculation results were compared with the experimental data. Next, sintered specimens obtained from two commercially available powder mixtures were studied. The aim of the investigations was to determine the influence of the mechanical and thermal parameters of the matrix materials on their retentive properties. The analysis indicated the mechanical parameters that are responsible for the retention of diamond particles in a matrix. These mechanical variables have been: the elastic energy of particle, the elastic energy of matrix and the radius of plastic zone around particle.

A Thermomechanical Model of Retention of a Diamond Particle in Matrices Based on Fe

2020 ◽  
Vol 405 ◽  
pp. 48-53
Author(s):  
Joanna Borowiecka-Jamrozek ◽  
Jan Lachowski
Keyword(s):  
Diamond Tool ◽  
Matrix Material ◽  
Diamond Particle ◽  
Metallic Matrix ◽  
Thermomechanical Model ◽  
Plastic Properties ◽  
Diamond Particles ◽  
The Matrix ◽  
Mechanical Bonding ◽  
Abaqus Software

The aim of this paper was to determine the influence of the mechanical and thermal parameters of the matrix materials on their retentive properties. The term ‘matrix retention’ denotes the capacity of a metallic matrix material to retain diamond particles at the surface of a diamond tool during working. The bonding is obtained during cooling after the hot pressing process. Proper mechanical bonding depends on elastic and plastic properties of the matrix. The model of a diamond particle embedded in a metallic matrix was created using Abaqus software. The analysis has indicated the mechanical parameters that are responsible for the retention of diamond particles in a matrix.

scholarly journals Numerical Analysis of Diamond Retention in Cobalt and a Copper-Base Alloy/ Analiza Numeryczna Retencji Kryształu Diamentu W Kobalcie I Stopie Miedzi

2014 ◽  
Vol 59 (4) ◽  
pp. 1457-1462 ◽  
Author(s):  
J. Konstanty ◽  
A. Romanski
Keyword(s):  
Strain Field ◽  
Diamond Crystal ◽  
Base Alloy ◽  
Cutting Tools ◽  
Metallic Matrix ◽  
Stress And Strain ◽  
Copper Base ◽  
The Matrix ◽  
Copper Base Alloy ◽  
Diamond Retention

Abstract Why cobalt outperforms other matrix materials in its capacity for diamond retention in cutting tools is considered. To this end diamond loading conditions were modelled to establish the magnitude of stress and strain in the matrix surrounding a working diamond crystal. Only at 315 N did the contact force in Co result in plastic strain of 4-8%, which has a destructive influence on diamond retention. The strain field generated in a poorly performing Cu-40%Co-6%Sn matrix under a load of 190 N closely resembled that generated by 315 N in Co. It is postulated that diamond retention is related to the yield strength and work hardening characteristics of the metallic matrix.

scholarly journals Higher-order Darboux transformations for two-dimensional Dirac systems with diagonal matrix potential

2021 ◽  
Vol 2090 (1) ◽  
pp. 012038
Author(s):  
A Schulze-Halberg
Keyword(s):  
Dirac Equation ◽  
Explicit Form ◽  
Higher Order ◽  
Diagonal Matrix ◽  
Two Dimensional ◽  
Darboux Transformations ◽  
Dirac Systems ◽  
Matrix Potential ◽  
De Vries ◽  
The Matrix

Abstract We construct the explicit form of higher-order Darboux transformations for the two-dimensional Dirac equation with diagonal matrix potential. The matrix potential entries can depend arbitrarily on the two variables. Our construction is based on results for coupled Korteweg-de Vries equations [27].

Exploration Study of Multifunctional Metallic Nanocomposite Utilizing Single-Walled Carbon Nanotubes for Micro/Nano Devices

2005 ◽  
Vol 219 (2) ◽  
pp. 67-72 ◽  
Author(s):  
Quanfang Chen ◽  
Guang Chai ◽  
Bo Li
Keyword(s):  
Carbon Nanotubes ◽  
Energy Transport ◽  
Metallic Matrix ◽  
Building Blocks ◽  
Copper Matrix ◽  
Interfacial Bonding ◽  
Single Walled Carbon ◽  
The Matrix ◽  
Raman Scattering Spectra ◽  
Multifunctional Properties

Carbon nanotubes (CNTs) are excellent multifunctional materials in terms of mechanical robustness, thermal, and electrical conductivities. These multifunctional properties, as well as the small size of the structures, make CNTs ideal building blocks in developing nanocomposites. However, the matrix materials and the fabrication processes are critical in achieving the expected multifunctional properties of a CNT-reinforced nanocomposite. This paper has proved that electrochemical co-deposition of a metallic nanocomposite is a good approach for achieving good interfacial bonding between CNTs and a metallic matrix. Good interfacial bonding between a single-walled carbon nanotube (SWCNT) and a copper matrix has been verified by enhanced fracture toughness (increased stickiness) and a shift in the Raman scattering spectra. For the Cu/SWCNT nanocomposite, the radial breath mode (RBM) has disappeared and the tangential or G-band has shifted and widened, which is an indication of better energy transport.

Inverse problem for one-dimensional wave equation with matrix potential

2019 ◽  
Vol 27 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Ammar Khanfer ◽  
Alexander Bukhgeim
Keyword(s):  
Inverse Problem ◽  
Wave Equation ◽  
Uniqueness Theorem ◽  
Cauchy Data ◽  
Global Uniqueness ◽  
One Dimensional ◽  
Matrix Potential ◽  
The Matrix ◽  
Real Matrices ◽  
Dimensional Wave

AbstractWe prove a global uniqueness theorem of reconstruction of a matrix-potential {a(x,t)} of one-dimensional wave equation {\square u+au=0}, {x>0,t>0}, {\square=\partial_{t}^{2}-\partial_{x}^{2}} with zero Cauchy data for {t=0} and given Cauchy data for {x=0}, {u(0,t)=0}, {u_{x}(0,t)=g(t)}. Here {u,a,f}, and g are {n\times n} smooth real matrices, {\det(f(0))\neq 0}, and the matrix {\partial_{t}a} is known.

scholarly journals An Experimental Study Of Aluminum Alloy Matrix Composite Reinforced SiC Made By Hot Pressing Method

2015 ◽  
Vol 60 (2) ◽  
pp. 1523-1527 ◽  
Author(s):  
M. Suśniak ◽  
J. Karwan-Baczewska ◽  
J. Dutkiewicz ◽  
M. Actis Grande ◽  
M. Rosso
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Matrix Composite ◽  
Hot Pressing ◽  
Metallic Matrix ◽  
High Energy ◽  
Composite Powders ◽  
Alloy Matrix ◽  
Pressing Method ◽  
Sic Particles

Abstract The present work investigates the possibility of using powder metallurgy processing for producing a metal matrix composite. Materials were prepared from AlSi5Cu2 chips with reinforcement of 10, 15, 20 wt. % silicon carbide. Aluminum alloy chips were milled with SiC powder in a high-energy ball mill by 40 hours. Mechanical alloying process lead to obtain an uniform distribution of hard SiC particles in the metallic matrix and refine the grain size. The consolidation of composite powders was performed by vacuum hot pressing at 450°C, under pressure of 600 MPa by 10 min. The results shows that the addition of SiC particles has a substantial influence on the microstructure and mechanical properties of composite powder as well as consolidated material. Hot pressing is an effective consolidation method which leads to obtain dense AlSi5Cu2/SiC composite with homogeneous structure and advanced mechanical properties.

Nanocomposite Bi(Sb)Te(Se) Materials by Cryogenic Mechanical Alloying and Optimized High Pressure Hot-pressing

2012 ◽  
Vol 1456 ◽  
Author(s):  
Tsung-ta E. Chan ◽  
Rama Venkatasubramanian ◽  
James M. LeBeau ◽  
Peter Thomas ◽  
Judy Stuart ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Hot Pressing ◽  
High Energy ◽  
Structural Features ◽  
Milling Process ◽  
Nanocrystalline Powders ◽  
Full Density ◽  
Seebeck Coefficients ◽  
The Matrix ◽  
Cryogenic Process

ABSTRACTNanocomposite Bi2Te3 based alloys are attractive for their potentially high thermoelectric figure-of-merit (ZT) around room temperature. The nano-scale structural features embedded in the matrix provide more scattering of phonons and can thus reduce the lattice thermal conductivity. To further take advantage of such nanocomposite structures, we focus on the development of nanocrystalline Bi(Sb)Te(Se) powders by high energy cryogenic mechanical alloying followed by an optimized hot pressing process. This approach is shown to successfully produce Bi(Sb)Te(Se) alloy powders with grain size averaging about 9 nm for n-type BiTe(Se) and about 16 nm for p-type Bi(Sb)Te respectively. This cryogenic process offers much less milling time and prevents thermally activated contamination or imperfections from being introduced during the milling process. The nanocrystalline powders are then compacted at optimized pressures and temperatures to achieve full density compactions and preserve the grain sizes effectively. The resulting nano-bulk materials have optimal Seebeck coefficients and are expected to have improved ZT. Thermoelectric properties and microstructure studies by X-ray diffraction and transmission electron microscopy will also be presented and discussed.

Fracture Mechanics Characterization of Sintered 30 Vol.-% Al2O3/TRIP Steel Composites Using SENB Miniature Samples

2015 ◽  
Vol 825-826 ◽  
pp. 899-906 ◽  
Author(s):  
Ralf Eckner ◽  
Alexander Illgen ◽  
Markus Radajewski ◽  
Lutz Krüger
Keyword(s):  
Trip Steel ◽  
Metallic Matrix ◽  
Stable Crack Growth ◽  
Ceramic Particle ◽  
Mechanical Tests ◽  
Matrix Composites ◽  
Operational Design ◽  
The Matrix ◽  
Microstructural Studies

Ceramic particle reinforced metal matrix composites (PRMMCs) combine the strength and brittleness of ceramics with the toughness of a metallic matrix. In order to use these materials in construction and operational design their fracture mechanical behavior must be evaluated. In this study, a 30 vol.-% Al2O3 reinforced austenitic TRIP steel processed by powder metallurgical technique was investigated using precracked miniature SENB-specimens in 3-point-bending. An elastic-plastic analysis by means of the J-integral method in combination with optical crack observation showed the materials ability of stable crack growth, i. e. R-curve behavior. In addition to the mechanical tests microstructural studies were performed, whereby particle debonding and fracture as well as martensitic phase transformation and crack bridging within the matrix were identified as fracture energy dissipating mechanisms.

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