scholarly journals Hall-Petch strengthening of the constrained metallic binder in WC–Co cemented carbides: Experimental assessment by means of massive nanoindentation and statistical analysis

2016 ◽  
Vol 676 ◽  
pp. 487-491 ◽  
Author(s):  
J.J. Roa ◽  
E. Jiménez-Piqué ◽  
J.M. Tarragó ◽  
D.A. Sandoval ◽  
A. Mateo ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Cemented Carbides ◽  
Metallic Binder ◽  
Experimental Assessment

scholarly journals Psychoacoustic Analysis of Vacuum Cleaner Noise

Acoustics ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 545-559
Author(s):  
Sanjay Kumar ◽  
Wong Sze Wing ◽  
Heow Pueh Lee
Keyword(s):  
Statistical Analysis ◽  
Hybrid Approach ◽  
Human Perception ◽  
Vacuum Cleaner ◽  
Experimental Assessment ◽  
Household Appliances ◽  
Psychoacoustic Metrics

Vacuum cleaners are one of the most widely used household appliances associated with unpleasant noises. Previous studies have indicated the severity of loud vacuum cleaner noise and its impact on the users nearby. The standalone quantified measurements of the generated noise are not sufficient for properly characterizing vacuum cleaners. Human perception should also be included for a better assessment of the quality of sound. A hybrid approach such as psychoacoustics analysis, which comprises subjective and objective evaluations of sounds, has recently been widely used. This paper focuses on the experimental assessment of vacuum cleaner noise and evaluates their psychoacoustical matrices. Three vacuum cleaners with different specifications have been selected as test candidates, and their sound qualities have been analyzed. Statistical analysis, ANOVA, has been performed in order to investigate the effectiveness of individual psychoacoustic metrics.

scholarly journals Effect of Metallic Binder Composition on Microstructure and Hardness of (W,Ti)C Cemented Carbides

2007 ◽  
Vol 14 (3) ◽  
pp. 208-214 ◽  
Author(s):  
Walid M. Daoush ◽  
Kyong-H. Lee ◽  
Hee-S. Park ◽  
Jong-J. Jang ◽  
Soon-H. Hong
Keyword(s):  
Cemented Carbides ◽  
Metallic Binder ◽  
Binder Composition

Microstructural Evolution of Composite 8 WC-(Co, Ni): Effect of the Addition of SiC

2017 ◽  
Vol 371 ◽  
pp. 78-85 ◽  
Author(s):  
Fabio Miranda ◽  
Daniel Rodrigues ◽  
Francisco Yastami Nakamoto ◽  
Carlos Frajuca ◽  
Givanildo Alves dos Santos ◽  
...  
Keyword(s):  
Grain Size ◽  
Bulk Material ◽  
Solid Solution Hardening ◽  
Cemented Carbides ◽  
Matrix Composites ◽  
Metallic Binder ◽  
Sintering Time ◽  
Microstructural Evaluation ◽  
The Matrix ◽  
Size Growth

Tungsten carbide (WC) based cemented carbides, also called hardmetals, are a family of composite materials consisting of carbide ceramic particles embedded in a metallic binder. They are classified as metal matrix composites (MMCs) because the metallic binder is the matrix that holds the bulk material together [1]. WC based composites are used in applications where a good combination of hardness and toughness are necessary [2]. It is usual to add more components to tailor the microstructure of the WC-(Co, Ni) system. The hardness for the cemented carbides based on nickel, increases significantly because of the addition of reinforcements like SiC nanowhisker [3]. In this work, the SiC was considered as an additional component for the composite WC-8(Co, Ni). Four mixtures were prepared with SiC contents ranging from 0 to 3.0 wt%. These mixtures were pressed (200 MPa) and green samples with 25.2 mm of diameter and 40 g were produced. Sintering was carried out in Sinter-HIP furnace (20 bar). Two sintering temperatures were investigated, i.e. 1380 and 1420oC, and the sintering time considered was 60 minutes. The relative density, hardness, linear and volumetric shrinkage were determined. Microstructural evaluation was investigated by optical microscopy and scanning electron microscopy (SEM-FEG). The results showed that the addition of SiC promoted higher densification and grain size growth. The hardness was higher for samples with SiC, so solid solution hardening of the binder was more effective than WC grain size growth.

Reactive sintering of WC-Ni-Co-Cr-Ti-Al cemented carbides and precipitation of gamma prime in their metallic binder phases

2020 ◽  
pp. 105427
Author(s):  
Tomas Soria Biurrun ◽  
Jazmina Navarrete Cuadrado ◽  
Unai Galech Napal ◽  
Belen Lopez Ezquerra ◽  
Lorena Lozada Cabezas ◽  
...  
Keyword(s):  
Cemented Carbides ◽  
Reactive Sintering ◽  
Metallic Binder ◽  
Gamma Prime

STATISTICAL ANALYSIS OF THE BEHAVIOUR OF CEMENTED CARBIDES UNDER HIGH PRESSURE

1974 ◽  
Vol 17 (33) ◽  
pp. 85-102 ◽  
Author(s):  
J. L. Chermant ◽  
M. Coster ◽  
G. Hautier ◽  
P. Schaufelberger
Keyword(s):  
High Pressure ◽  
Statistical Analysis ◽  
Cemented Carbides

Statistical analysis of classification

1966 ◽  
Vol 24 ◽  
pp. 188-189
Author(s):  
T. J. Deeming
Keyword(s):  
Multivariate Analysis ◽  
Statistical Analysis ◽  
Classification Scheme ◽  
Analytical Procedure ◽  
Narrow Band ◽  
Scientific Research ◽  
Maximum Amount ◽  
Amount Of Information

If we make a set of measurements, such as narrow-band or multicolour photo-electric measurements, which are designed to improve a scheme of classification, and in particular if they are designed to extend the number of dimensions of classification, i.e. the number of classification parameters, then some important problems of analytical procedure arise. First, it is important not to reproduce the errors of the classification scheme which we are trying to improve. Second, when trying to extend the number of dimensions of classification we have little or nothing with which to test the validity of the new parameters.Problems similar to these have occurred in other areas of scientific research (notably psychology and education) and the branch of Statistics called Multivariate Analysis has been developed to deal with them. The techniques of this subject are largely unknown to astronomers, but, if carefully applied, they should at the very least ensure that the astronomer gets the maximum amount of information out of his data and does not waste his time looking for information which is not there. More optimistically, these techniques are potentially capable of indicating the number of classification parameters necessary and giving specific formulas for computing them, as well as pinpointing those particular measurements which are most crucial for determining the classification parameters.

Microstructure of Electro-Eroded Cemented Carbide Surfaces

1968 ◽  
Vol 26 ◽  
pp. 284-285
Author(s):  
V. N. Filimonenko ◽  
M. H. Richman ◽  
J. Gurland
Keyword(s):  
Surface Layer ◽  
Cobalt Content ◽  
Cemented Carbides ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Metallographic Examination ◽  
Standard Procedures ◽  
Face Centered ◽  
Diamond Paste ◽  
Plastic Carbon

The high temperatures and pressures that are found in a spark gap during electrical discharging lead to a sharp phase transition and structural transformation in the surface layer of cemented carbides containing WC and cobalt. By means of X-ray diffraction both W2C and a high-temperature monocarbide of tungsten (face-centered cubic) were detected after electro-erosion. The W2C forms as a result of the peritectic reaction, WC → W2C+C. The existence and amount of the phases depend on both the energy of the electro-spark discharge and the cobalt content. In the case of a low-energy discharge (i.e. C=0.01μF, V = 300v), WC(f.c.c.) is generally formed in the surface layer. However, at high energies, (e.g. C=30μF, V = 300v), W2C is formed at the surface in preference to the monocarbide. The phase transformations in the surface layer are retarded by the presence of larger percentages of cobalt.Metallographic examination of the electro-eroded surfaces of cemented carbides was carried out on samples with 5-30% cobalt content. The specimens were first metallographically polished using diamond paste and standard procedures and then subjected to various electrical discharges on a Servomet spark machining device. The samples were then repolished and etched in a 3% NH4OH electrolyte at -0.5 amp/cm2. Two stage plastic-carbon replicas were then made and shadowed with chromium at 27°.

Quantitative parallel EELS spectrum imaging developed as a new tool in AEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1202-1203
Author(s):  
Gianluigi Botton ◽  
Gilles L'espérance
Keyword(s):  
Statistical Analysis ◽  
Spatial Resolution ◽  
Personal Computer ◽  
Systematic Study ◽  
Present Author ◽  
Chemical Elements ◽  
Detection Limits ◽  
Research Groups ◽  
Quantitative Performance ◽  
Spectrum Imaging

As interest for parallel EELS spectrum imaging grows in laboratories equipped with commercial spectrometers, different approaches were used in recent years by a few research groups in the development of the technique of spectrum imaging as reported in the literature. Either by controlling, with a personal computer both the microsope and the spectrometer or using more powerful workstations interfaced to conventional multichannel analysers with commercially available programs to control the microscope and the spectrometer, spectrum images can now be obtained. Work on the limits of the technique, in terms of the quantitative performance was reported, however, by the present author where a systematic study of artifacts detection limits, statistical errors as a function of desired spatial resolution and range of chemical elements to be studied in a map was carried out The aim of the present paper is to show an application of quantitative parallel EELS spectrum imaging where statistical analysis is performed at each pixel and interpretation is carried out using criteria established from the statistical analysis and variations in composition are analyzed with the help of information retreived from t/γ maps so that artifacts are avoided.

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