Study and Development of a Multilayered Coating to Improve Hard Metal Cutting Tools Performances

2018 ◽  
Vol 941 ◽  
pp. 1656-1661
Author(s):  
Federico Simone Gobber ◽  
Mario Rosso
Keyword(s):  
Metal Cutting ◽  
Multilayer Coating ◽  
Cutting Tools ◽  
Hard Metal ◽  
Point Of View ◽  
Thin Layers ◽  
Mechanical Working ◽  
Heat Resistant Alloy ◽  
Experimental Cutting ◽  
The Difference

The use of coated hard metal is spread in all fields of mechanical working, both forming and machining. Different hard metals are used based on their mechanical characteristic that strongly depends on composition and grain size. Substrates such as HSS and WC – Co are typically coated with PVD thin layers in applications such as metalworking and cutting; thus lot of efforts are put in researching this specific field. Coating composition, and coating architecture are paramount topics in the subsject of surface anti – wear thin films. The focus of this study is to analyze the difference between two AlTiN coatings, a monolayer and a multilayer with gradient composition, from the point of view of microstructure and adhesion. Experimental cutting tests were done to characterize the behavior of the coating in face milling of AISI 660 heat resistant alloy: varying cutting speeds from 15 to 40 m/min it was finally assessed that a multilayer coating can give higher tool life with respect to a monolayer coating of the same composition.

High Current Extended DC Arc Plasma CVD for Mass Production of Diamond Film Coated Hard Metal Cutting Tools

2011 ◽  
Vol 211-212 ◽  
pp. 766-769 ◽  
Author(s):  
Fan Xiu Lu ◽  
Yong Ping Lv ◽  
Li Fu Hei ◽  
Wei Zhong Tang ◽  
Jian Hua Song
Keyword(s):  
Diamond Film ◽  
Mass Production ◽  
Metal Cutting ◽  
High Efficiency ◽  
Cutting Tools ◽  
Hard Metal ◽  
High Current ◽  
Plasma Cvd ◽  
Dry Cutting ◽  
Dc Arc

Diamond film coated hard metal cutting tools are indispensible for high efficiency machining of materials which are difficult to cut by ordinary tools, and are successfully used in the dry cutting of high silicon content Al-Si cast alloys, graphite, carbon reinforced composite (CRFC) and metal matrix composite (MMC) , ceramics, and many other materials. In the present presentation, a novel process of High Current Extended DC Arc (HCEDCA) plasma CVD for mass production of diamond film coated hard metal cutting tools is presented. Besides, a novel process for the pretreatment of the hard metal cutting tool substrate, which involves the idea of “surface engineering” consisting of boronizing and alkaline and acidic etching is also discussed, by which the adhesion of the diamond film coating to the hard metal substrate can be greatly enhanced. Highly adherent and uniform diamond film coatings are successfully obtained. Diamond film coated WC-6wt%Co indexable tool bits, drills, endmill samples have been produced and been shown having excellent cutting performance by field cutting tests in dry cutting of Al-12%Si cast alloy and Al-15% SiC MMC materials.

A new quick-stop device to study the chip formation mechanism in metal cutting: Computational and experimental investigation

2021 ◽  
pp. 095440622110342
Author(s):  
Mohamed Baccar Mhamdi ◽  
Wajdi Rajhi ◽  
Mohamed Boujelbene ◽  
Sahbi Ben Salem ◽  
Sonia Ezeddini ◽  
...  
Keyword(s):  
Chip Formation ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Cutting Parameters ◽  
Hard Metal ◽  
Formation Mechanisms ◽  
Machining Parameters ◽  
Chip Formation Mechanism ◽  
Aisi D2 ◽  
Stop Test

Understanding the chip formation mechanisms during machining is an important factor to facilitate the choice of cutting tools and machining parameters. Despite the appearance of new sophisticated methods and advanced equipment, the technique so called quick-Stop Test (QST) remains efficient, less costly, and easier to apply in the investigation of chip formation in cutting process. In present paper a new Quick-Stop Device QSD is designed, numerically simulated, implemented, and tested. The reformed QST technique uses a QSD device which operates on the modified Charpy pendulum. Accordingly, design of new QSD is presented and deeply described, and 2D FE modeling of the new QST, including the application of the appropriate boundary conditions, has been carried out. Moreover, chip formation and morphology for different cutting conditions have been effectively simulated. Subsequently, quick stop cutting operations including metal cutting tests of high alloyed tool steel (AISI D2) using fabricated new QSD are performed. Preliminary results of quick-stop experiment from current investigation prove the effectiveness of the new designed QSD in matter of rigidity, safety, and absence of vibration, while providing a fast set up time and allowing extremely short workpiece-cutting tool separation time and guarantee the generation of chip with its root. The photomicrographs of chip root samples gathered from hard metal cutting experiments including various cutting speeds machining conditions, enables clear observation of segmented chip formation mechanisms, thereby, highly promising the new designed QSD for the purpose of investigation of the different cutting parameters influencing the chip formation and morphology.

The linear properties of thin layers, with an application to synthetic seismograms over coal seams

Geophysics ◽  
1980 ◽  
Vol 45 (8) ◽  
pp. 1254-1268 ◽  
Author(s):  
O. Koefoed ◽  
N. de Voogd
Keyword(s):  
Seismic Signal ◽  
Dominant Frequency ◽  
Sine Wave ◽  
Synthetic Seismograms ◽  
Point Of View ◽  
Thin Layers ◽  
Integer Number ◽  
Coal Seams ◽  
Order Of Magnitude ◽  
The Difference

Thin layers are considered from the point of view of the quasi‐linear relation that exists between their thickness and their reflection response to a seismic signal. The range within which this quasi‐linearity exists is investigated; for a continuous sine wave, this is done by means of the equation for the response given in Rayleigh (1945), and for a seismic wavelet by means of a synthetic seismogram program. For a wavelet, the limiting value of the dominant frequency is found to be smaller than that for a continuous sine wave, the difference being in the order of magnitude of 15 percent. Within the linearity range, a thin layer may be replaced by an equivalent layer which gives the same reflection response but differs in thickness and in acoustic impedance. In the construction of synthetic seismograms over coal seams, this equivalent replacement may be utilized to replace the seams by layers, for which the two‐way traveltime is equal to an integer number of sampling intervals; by this procedure the usual rounding‐off errors are avoided. The method of equivalent replacement is also applicable when the host rock above and below the seam have different velocities.

Production, Characterization, and Wear Behaviour of Plasma Jet CVD Diamond Films on Hard Metal Cutting Tools

1996 ◽  
Vol 154 (1) ◽  
pp. 403-422 ◽  
Author(s):  
F. Deuerler ◽  
M. Pies ◽  
H. van den Berg ◽  
R. Tabersky ◽  
V. Buck
Keyword(s):  
Metal Cutting ◽  
Cutting Tools ◽  
Diamond Films ◽  
Plasma Jet ◽  
Cvd Diamond ◽  
Hard Metal ◽  
Wear Behaviour

Pretreatment of substrate surface for improved adhesion of diamond films on hard metal cutting tools

1996 ◽  
Vol 5 (12) ◽  
pp. 1478-1489 ◽  
Author(s):  
F. Deuerler ◽  
H. van den Berg ◽  
R. Tabersky ◽  
A. Freundlieb ◽  
M. Pies ◽  
...  
Keyword(s):  
Metal Cutting ◽  
Substrate Surface ◽  
Cutting Tools ◽  
Diamond Films ◽  
Hard Metal

Pleasure as a Sign of Efficacy of Mental Activity

1997 ◽  
Vol 2 (3) ◽  
pp. 226-234 ◽  
Author(s):  
Michel Cabanac ◽  
Chantal Pouliot ◽  
James Everett
Keyword(s):  
Evolutionary Psychology ◽  
Magnitude Estimation ◽  
Mental Activity ◽  
Point Of View ◽  
Macintosh Computer ◽  
Science Students ◽  
Cognitive Efficiency ◽  
Sensory Pleasure ◽  
The Difference ◽  
Mental Tasks

Previous work has shown that sensory pleasure is both the motor and the sign of optimal behaviors aimed at physiological ends. From an evolutionary psychology point of view it may be postulated that mental pleasure evolved from sensory pleasure. Accordingly, the present work tested empirically the hypothesis that pleasure signals efficacious mental activity. In Experiment 1, ten subjects played video-golf on a Macintosh computer. After each hole they were invited to rate their pleasure or displeasure on a magnitude estimation scale. Their ratings of pleasure correlated negatively with the difference par minus performance, i.e., the better the performance the greater the pleasure reported. In Experiments 2 and 3, the pleasure of reading poems was correlated with comprehension, both rated by two groups of subjects, science students and arts students. In the majority of science students pleasure was significantly correlated with comprehension. Only one arts student showed this relationship; this result suggests that the proposed relationship between pleasure and cognitive efficiency is not tautological. Globally, the results support the hypothesis that pleasure is aroused by the same mechanisms, and follows the same laws, in physiological and cognitive mental tasks and also leads to the optimization of performance.

COMBINATORIAL POLYNOMIALLY COMPUTABLE CHARACTERISTICS OF SUBSTITUTIONS AND THEIR PROPERTIES

2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  
Keyword(s):  
Mathematical Expectation ◽  
Point Of View ◽  
Small Range ◽  
Computational Point ◽  
Wide Range ◽  
Bijective Function ◽  
The Difference ◽  
Element Base ◽  
Selection Of

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.

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