Study of the Distribution of the Life of HSS Tools

1971 ◽  
Vol 93 (4) ◽  
pp. 1044-1050 ◽  
Author(s):  
J. G. Wager ◽  
M. M. Barash
Keyword(s):  
Tool Life ◽  
High Speed ◽  
Low Carbon Steel ◽  
High Speed Steel ◽  
Distribution Patterns ◽  
Similar Distribution ◽  
Low Carbon ◽  
Mean Values ◽  
Life Tests ◽  
Life Predictions

Numerous life tests carried out with high speed steel tools in machining low carbon steel indicate that tool life values are subject to a statistical distribution which can be approximated by the normal distribution with a coefficient of variation of about 0.3. Accelerated and normal tests show similar distribution patterns, which indicates a possibility for a wider use of accelerated tests. The conventionally accepted concepts of tool life “constant” and “exponent” should be considered only as representing statistical mean values which are not sufficient for the prediction of the life of any individual tool put to work. It is recommended that tool life predictions be made on a probabilistic basis, and the desired direction of further studies is indicated.

Relationship Between Alloy Composition and Tool-Life of High-Speed Steel Twist Drills

1992 ◽  
Vol 114 (4) ◽  
pp. 459-464 ◽  
Author(s):  
W. E. Henderer
Keyword(s):  
Tool Life ◽  
High Speed ◽  
Alloy Composition ◽  
High Speed Steel ◽  
Vanadium Content ◽  
The Matrix ◽  
Life Tests ◽  
And Performance ◽  
Twist Drills ◽  
The Relationship

Tool-life tests are reported which show the relationship between the alloy composition of high-speed steel twist drills and performance. Tool-life is shown to depend primarily on the composition of the matrix consisting of tempered martensite and precipitated secondary carbides. The longest tool-life was obtained from alloys with high vanadium content and low tungsten or molybdenum content. This observation is consistent with the dispersion characteristics of vanadium carbide which precipitate during tempering.

Modeling of Forces for Drills With Chip-Breaking Grooves

2004 ◽  
Vol 126 (3) ◽  
pp. 555-564 ◽  
Author(s):  
Sushanta K. Sahu ◽  
Richard E. DeVor ◽  
Shiv G. Kapoor
Keyword(s):  
Cutting Forces ◽  
High Speed ◽  
Low Carbon Steel ◽  
High Speed Steel ◽  
Mechanistic Modeling ◽  
Design Parameters ◽  
Low Carbon ◽  
Workpiece Material ◽  
Chip Breaking ◽  
Twist Drills

In this paper, a mechanistic modeling approach to predicting cutting forces for conical twist drills with chip-breaking grooves has been developed. The model is based on force principles for restricted contact cutting extended to take into account the presence of a groove on the drill rake face. The applicability of the model for arbitrary groove geometries has been ensured by eliminating the use of grooved drills in the calibration process. Four different combinations of groove geometries have been used for validating the model using high speed steel drills and low carbon steel workpiece material. The force predictions from the model were found to be in good agreement with the measured forces. The model was then employed to determine groove orientation and design parameters that minimize cutting forces, subject to the condition that chip breaking is satisfactory.

Strengthening Mechanisms in High-Speed Steel as Related to Tool-Life

1979 ◽  
Vol 101 (2) ◽  
pp. 217-222 ◽  
Author(s):  
W. E. Henderer
Keyword(s):  
Yield Strength ◽  
Tool Life ◽  
High Speed ◽  
High Speed Steel ◽  
Precipitation Strengthening ◽  
Strengthening Mechanisms ◽  
Precipitation Sequence ◽  
Tempering Temperature ◽  
Life Tests ◽  
Secondary Hardness

Tool-life tests are reported which show that the performance of AISI M1 high speed steel taps responds to the tempering temperature in the same manner as the yield strength. The metallurgical transformations which occur during tempering are described in detail with specific attention given to the precipitation reactions which occur over the temperature range of peak secondary hardness. The variation in yield strength is found to be consistent with a coherent-incoherent precipitation sequence of alloy carbides during tempering. An estimate of the yield strength is made based on dislocation theories of martensitic and precipitation strengthening.

Effect of residual elements on the machinability of leaded free machining steels

1980 ◽  
Vol 295 (1413) ◽  
pp. 87-88 ◽  
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Tool Life ◽  
High Speed ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Tool Material ◽  
High Speed Steel ◽  
Low Carbon ◽  
Wear Rates

The machinability of a material can be defined in terms of the wear rate of the cutting tool used to machine the material. The lower the tool wear rate or the greater the tool life the better the machinability. The wear processes of cutting tools are complicated, but recent work has shown that cutting tool wear rates during machining can be directly related to tool material wear rates when rubbing in a modified crossed cylinder wear experiment (Mills & Akhtar 1975). The wear of cutting tools can be simulated by simple experiments. Here I present results on the effect of total residual levels in leaded low carbon free machining steels on the tool life of M2 high speed steel. The results will be discussed in terms of a simple wear model.

Influence of the choice of wear criterion on the life of high speed machine manual taps

2020 ◽  
pp. 74-78
Author(s):  
A.E. Dreval
Keyword(s):  
Service Life ◽  
Structural Steel ◽  
Tool Life ◽  
High Speed ◽  
High Speed Steel ◽  
Parameter Dependence ◽  
Limiting State ◽  
Thread Cutting ◽  
Failure Life ◽  
High Speed Machine

The assessment of the limiting state of high-speed machine-manual taps in the processing of structural steel billets is considered. A general multi-parameter dependence is developed for calculating the criterion of allowable wear, which makes it possible to rationally use the tool life and normalize the cut amount during regrinding. Keywords thread cutting, tap, angle of the cutting part, criterion, high-speed steel, wear, failure, life, service life. [email protected]

Aluminum nitride buffer layer for diamond film growth

1996 ◽  
Vol 11 (7) ◽  
pp. 1810-1818 ◽  
Author(s):  
V. P. Godbole ◽  
J. Narayan
Keyword(s):  
Aluminum Nitride ◽  
Buffer Layer ◽  
Diamond Film ◽  
High Speed ◽  
Film Growth ◽  
High Speed Steel ◽  
Bearing Steel ◽  
Low Carbon ◽  
Wide Range ◽  
Steel Substrates

The role of aluminum nitride (AlN) as a buffer layer on the nucleation and growth of diamond on silicon and steel substrates during hot filament chemical vapor deposition (HF-CVD) has been investigated systematically. The scanning Auger electron microscopy (AES) is employed to study chemistry and content of carbon on the surface and in subsurface regions of AlN as a function of HF-CVD parameters. It is found that AlN offers an excellent diffusion barrier for carbon over a wide range of temperature and hydrocarbon content of CVD gas environment, with simultaneous inhibition of graphitization. It also facilitates nucleation of diamond phase. The surface reactions between AlN and carbon are discussed in terms of hydrogen-assisted phase transformations. We have developed a two-step procedure to obtain a continuous diamond film on steel substrates. The characteristic features of AlN have been exploited to obtain adherent and graphite-free diamond deposits on various types of steels, including low carbon steel, tool steel, high speed steel, and bearing steel.

scholarly journals Tribological properties of ion-modified composite coatings

2021 ◽  
Vol 2059 (1) ◽  
pp. 012015
Author(s):  
M Sh Migranov ◽  
A M Migranov ◽  
S R Shekhtman
Keyword(s):  
Wear Resistance ◽  
Tool Life ◽  
High Speed ◽  
Composite Coatings ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Hard Coating ◽  
Ion Nitriding ◽  
Additional Layer ◽  
Nitrided Surface

Abstract The paper presents the results of a study of one of the ways to increase the wear resistance of “duplex” coatings applied to cutting tools, which are due to preliminary diffusion saturation of the tool surface with nitrogen (known as ion nitriding) followed by physical deposition of a hard coating (Ti, Cr) N. The proposed coating also contains an additional layer with an impurity of ions, deposited on a preliminary nitrided surface of high speed steel before the deposition of a hard coating. Tests were carried out to evaluate the effect of these modified layers on the tool life of the HSS tool. The greatest wear resistance after "triplex" - treatment was achieved during ion implantation of titanium into a pre-nitrided surface. The coefficient of friction of the modified layer was studied at different contact temperatures. Ionic mixing contributes to the appearance of a thin surface layer with an amorphous-like structure, which prolongs the stage of normal wear, which significantly increases the tool life as a result of the self-organization process.

scholarly journals Threading Performance of Different Coatings for High Speed Steel Tapping

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 464
Author(s):  
Alain Gil Del Val ◽  
Fernando Veiga ◽  
Octavio Pereira ◽  
Luis Norberto Lopez De Lacalle
Keyword(s):  
Tool Life ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Steel ◽  
Tialn Coating ◽  
Tool Performance ◽  
Thread Profile ◽  
Increase Tool Life

Threading holes using tapping tools is a widely used machining operation in the industry. This manufacturing process involves a great tool immersion in the part, which involves both friction and cutting. This makes the use of coatings critical to improving tool life. Four coatings are used based on Physical vapor deposition (PVD) technology—TiN, TiCN, TiAlN and TiAlN+WC/C are compared to uncoated tool performance. The effect of various coatings on the life of M12 × 1.5 tapping tools during threading of through holes 20 mm deep, in GG25 casting plates, dry and applying cutting speed of 50 m/min. The end-of-life criterion has been established based on a cutting torque of 16 N-m. Taking the uncoated tap as a basis for comparison, it is observed that coatings based on PVD technologies increase tool life doubling in the most advantageous case with the TiAlN coating. PVD type coatings provide better protection to wear at cylindrical area of the tool, where the thread profile is finished, than uncoated taps. The teeth located in the cone-cylinder transition zone of the taps suffer the most wear regardless of the coating. However, taps coated with TiAlN+WC/C wear level values is lowest of all the coatings tested, which indicates a strong reinforcement in these teeth.

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