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.

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.

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.

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.

DESIGN AND PLANNING OF LOW PERMEABILITY RESERVOIR STIMULATION BY ACID TREATMENT: AN INTEGRATED LABORATORY ANALYSIS

1999 ◽  
Vol 39 (1) ◽  
pp. 548
Author(s):  
T. Azizi ◽  
M.M. Rahman ◽  
S.S. Rahman
Keyword(s):  
Acid Treatment ◽  
Computer Modelling ◽  
Material Balance ◽  
Laboratory Analysis ◽  
Reservoir Stimulation ◽  
Treatment Conditions ◽  
The Matrix ◽  
Different Temperatures ◽  
Porosity And Permeability ◽  
Injection Rates

The matrix reactivity of sandstone formations with mixtures of hydrofluoric (HF) and hydrochloric (HC1) acids has been studied experimentally using natural cores. A systematic approach, which includes laboratory analysis and computer modelling, has been used to design and plan acid treatment for sandstone formations. Matrix reactivity to acid mixtures (reaction rate) and the relationship between the porosity and permeability are established by subjecting the Pacoota Sandstone core samples to different acid concentrations and injection rates at different temperatures. Based on material balance and reaction kinetics a numerical simulator has been developed and verified in the laboratory. This simulator can adequately predict spent-acid concentration and changes in porosity and permeability as a function of acid penetration depth for given acid treatment conditions (acid concentrations, injection rates and treatment temperatures).

scholarly journals Study of the Effect of Intake Layout on the Wavefront in a Beam Expanding System of a Telescope

2020 ◽  
Vol 10 (10) ◽  
pp. 3643
Author(s):  
Qingpeng Zhang ◽  
Yi Tan ◽  
Ge Ren ◽  
Tao Tang
Keyword(s):  
High Reliability ◽  
Wavefront Aberration ◽  
Flow State ◽  
Analysis Method ◽  
Smooth Flow ◽  
Main Disadvantage ◽  
The Matrix ◽  
Calculation Results ◽  
Ray Tracing Simulation ◽  
Small Holes

The main disadvantage of windowless beam expansion systems is that they cannot achieve a good sealing effect. Turbulence and impurities in the environment can easily affect the imaging and primary mirror. Thus, in this study, a matrix of small holes was introduced for inflation to form a stable and smooth flow inside the system to avoid these disadvantages. In order to study the layout of the matrix, the flow state of the model was analysed, and the Lorentz–Lorenz formula and Barron gradient operator were used for ray tracing. Simulation results show that when the matrix of small holes is arranged in 16 rows with 360 holes in each row, inflation has a lesser effect on the wavefront aberration of the system. Moreover, the root mean square (RMS) of wavefront aberration was only 0.077 μm, which was superior to the other layouts considered. Experimental results show that the RMS was 0.08 μm in this state, which is consistent with the analysis. This indicates that this analysis method can meet actual work needs. The calculation methods and calculation results have high reliability and, thus, can be also used in similar situations.

scholarly journals Characterization of the microstructure, microsegregation, and phase composition of ex-situ Fe–Ni–Cr–Al–Mo–TiCp composites fabricated by three-dimensional plasma metal deposition on 10CrMo9–10 steel

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Łukasz Rakoczy ◽  
Kevin Hoefer ◽  
Małgorzata Grudzień-Rakoczy ◽  
Bogdan Rutkowski ◽  
Marcin Goły ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Composite Coatings ◽  
Thermodynamic Simulation ◽  
Iron Concentration ◽  
Ex Situ ◽  
Chemical Compositions ◽  
Powder Mixtures ◽  
Equivalent Radius ◽  
X Ray ◽  
The Matrix

Abstract Quaternary powder mixtures yNi–20Cr–1.5Al–xTiCp (y = 78.5, 73.5, 68.5; x = 0, 5, 10) were deposited on ferritic 10CrMo9–10 steel to form on plates ex-situ composite coatings with austenitic-based matrix. Plasma deposition was carried out with various parameters to obtain eight variants. The microstructure, chemical composition, phase constitution, phase transformation temperatures, and microhardness of the two reference TiCp-free coatings and six ex-situ composites were investigated by X-ray diffraction, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermodynamic simulation, and Vickers microhardness measurements. All composites had an austenite matrix with lattice parameter a = 3.5891–3.6062 Å, calculated according to the Nelson–Riley extrapolation. Microstructural observations revealed irregular distribution of TiCp in the composites. Large particles generally occurred near the external surface due to the acting buoyancy effect, whereas in the interior smaller particles, with an equivalent radius around 0.2–0.6 μm, were present. Due to initial differences in the chemical composition of powder mixtures and also subsequent intensive mixing with the low-alloy steel in the liquid pool, the matrix of the composites was characterized by various chemical compositions with a dominating iron concentration. Interaction of TiCp with matrix during deposition led to the formation of nano-precipitates of M23C6 carbides at the interfaces. Based on the ThermoCalc simulation, the highest solidus and liquidus temperatures of the matrix were calculated to be for the composite fabricated by deposition of 73.5Ni–20Cr–1.5Al–5TiCp powder mixture at I = 130 A. The mean microhardness of the TiCp-free coatings was in the range 138–146 μHV0.1, whereas composites had hardnesses at least 50% higher, depending on the initial content of TiCp.

Basic Aspects of X-Ray Absorption In Quantitative Diffraction Analysis of Powder Mixtures

1989 ◽  
Vol 4 (2) ◽  
pp. 66-69 ◽  
Author(s):  
Leroy Alexander ◽  
Harold P. Klug
Keyword(s):  
Internal Standard ◽  
Case Analysis ◽  
Direct Analysis ◽  
Powder Mixtures ◽  
Powder Specimen ◽  
X Ray ◽  
The Matrix ◽  
Matrix Concentration ◽  
Mathematical Relationships ◽  
X Ray Absorption

AbstractThe mathematical relationships are developed which are pertinent to the quantitative analysis of powder mixtures for the case of diffraction from the surface of a flat powder specimen. These formulas relate the diffracted intensity to the absorptive properties of the sample. Three important cases are treated: (1) Mixture of n components; absorbing powder of the unknown equal to that of the matrix; concentration proportional to intensity. Direct analysis is permitted. (2) Binary mixture; absorbing powder of the unknown not equal to that of the diluent; concentration not proportional to intensity. Direct analysis is possible by means of calibration curves prepared from synthetic mixtures. (3) Mixture of n components; absorbing power of the unknown not equal to that of the matrix; general case. Analysis is accomplished by the addition of an internal standard. Concentration is proportional to the ratio of the intensity of a selected reflection from the unknown to the intensity of a reflection from the internal standard.

The Regularization Method with Morbid Problems of Equality Constraints

2013 ◽  
Vol 416-417 ◽  
pp. 1025-1033
Author(s):  
Chao Zhong Ma ◽  
Yuan Lu Du ◽  
Yong Wei Gu ◽  
Ji Fu ◽  
Qing Ming Gui
Keyword(s):  
Regularization Method ◽  
Equality Constraints ◽  
Network Problems ◽  
The Matrix ◽  
Pathological Model ◽  
Calculation Results ◽  
Free Network ◽  
Model Adjustment ◽  
The Difference ◽  
Full Consideration

The difference between the parameters and reasonable equality constraints can significantly improve the precision of classical least squares solution to eliminate the rank loss free network problems, and also can improve the pathological solution of the model, which presents the measurement adjustment equality constraints attached pathological model. This paper establishes the equality constraints morbid Model Adjustment regularization criteria, to give the solution of the model, and gives the statistical analysis to understand the nature. Based on this data, and giving full consideration of inevitable gross errors, it puts forward robust regularized factor mean square error minimization criteria and numerical solution. A variety of programs the calculation results show that the method not only can eliminate the adverse effects of the matrix morbid, but also can be able to overcome the presence of gross errors caused by instability, which is a good estimate.

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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