Some Controlled Metal-Cutting Studies With Resulfurized Steels

1961 ◽  
Vol 83 (4) ◽  
pp. 513-522 ◽  
Author(s):  
E. G. Thomsen ◽  
S. Kobayashi ◽  
M. C. Shaw
Keyword(s):  
Shear Stress ◽  
Plastic Flow ◽  
Contact Area ◽  
Metal Cutting ◽  
Flank Wear ◽  
Strength Properties ◽  
Dynamic Shear ◽  
Compression Tests ◽  
Low Sulfur ◽  
Cutting Speeds

Cutting tests, including controlled tool-chip contact area and controlled artificial flank wear-land studies, were made with five resulfurized steels having nearly identical strength properties. It was found that the dynamic shear stress was 62,700 psi and appeared to be identical for all steels at the two cutting speeds of 356 and 936 fpm with sulfur contents of the alloys ranging from 0.11 to 0.37 per cent. For the low sulfur steel (S = 0.033 per cent), the dynamic shear stress was found to be 72,000 psi. A comparison of the effective stresses obtained from compression tests with those from metal cutting tests showed good correlation at equal strains. The controlled tool-chip contact area and the controlled wear-land studies at feeds of approximately 0.005 ipr and cutting speeds of 318 to 356 fpm appear to indicate that sublayer plastic flow at the tool chip and tool work interfaces was essentially absent.

Dynamic Shear Stress—Analysis of Single Crystal Machining Studies

1973 ◽  
Vol 95 (4) ◽  
pp. 939-944 ◽  
Author(s):  
S. Ramalingam ◽  
J. Hazra
Keyword(s):  
Shear Stress ◽  
Single Crystal ◽  
Stress Analysis ◽  
Single Crystals ◽  
Plastic Flow ◽  
Metal Cutting ◽  
Dynamic Shear ◽  
Polycrystalline Aluminum ◽  
Cutting Problem ◽  
Good Agreement

Experimental results obtained when single crystals of aluminum of known orientation are machined under identical cutting conditions are presented. Analysis of the data obtained shows that the dynamic shear stress remains constant for all orientations tested and is in good agreement with the calculated value for polycrystalline aluminum. The implications of these results to metal cutting theory and the metal physical foundations on which the concept of dynamic shear stress, as a true material property, rests are discussed. The possible role that the dynamic shear stress may play in determining the geometry of the metal cutting problem, a problem in partially constrained plastic flow of metals, is discussed.

Controlled Contact Cutting Tools

1959 ◽  
Vol 81 (2) ◽  
pp. 139-147 ◽  
Author(s):  
B. T. Chao ◽  
K. J. Trigger
Keyword(s):  
Shear Stress ◽  
Surface Finish ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Substantial Reduction ◽  
Cutting Fluids ◽  
Dynamic Shear ◽  
Effective Utilization ◽  
High Speed Cutting

A substantial reduction in power consumption, an increase in tool life, more effective utilization of cutting fluids, and improved surface finish on the machined workpiece have been achieved by suitably controlling the length of tool-chip contact. Reasons for these findings are discussed in terms of basic variables in chip formation mechanics. Artificially restricted contact tools open new avenues for metal cutting research. Machining data obtained with such tools provide further evidence of the invariant behavior of the dynamic shear stress of metals under high-speed cutting conditions, and unfold interesting information on the intricate nature of tool-chip contact.

scholarly journals Room-temperature deformation of single crystals of ZrB2 and TiB2 with the hexagonal AlB2 structure investigated by micropillar compression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhenghao Chen ◽  
Bhaskar Paul ◽  
Sanjib Majumdar ◽  
Norihiko L. Okamoto ◽  
Kyosuke Kishida ◽  
...  
Keyword(s):  
Single Crystals ◽  
Plastic Flow ◽  
Room Temperature ◽  
Resolve Shear Stress ◽  
Temperature Deformation ◽  
Slip Systems ◽  
Compression Tests ◽  
Plastic Deformation Behavior ◽  
Bulk Single Crystals ◽  
Micropillar Compression

AbstractThe plastic deformation behavior of single crystals of two transition-metal diborides, ZrB2 and TiB2 with the AlB2 structure has been investigated at room temperature as a function of crystal orientation and specimen size by micropillar compression tests. Although plastic flow is not observed at all for their bulk single crystals at room temperature, plastic flow is successfully observed at room temperature by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> in ZrB2 and by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> in TiB2. Critical resolve shear stress values at room temperature are very high, exceeding 1 GPa for all observed slip systems; 3.01 GPa for {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> slip in ZrB2 and 1.72 GPa and 5.17 GPa, respectively for {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> slip in TiB2. The identified operative slip systems and their CRSS values are discussed in comparison with those identified in the corresponding bulk single crystals at high temperatures and those inferred from micro-hardness anisotropy in the early studies.

scholarly journals Flow deformation characteristics of African blackwood, Dalbergia melanoxylon

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Kazushi Nakai ◽  
Soichi Tanaka ◽  
Kozo Kanayama ◽  
Tsuyoshi Yoshimura
Keyword(s):  
Plastic Flow ◽  
Local Community ◽  
Tangential Direction ◽  
Musical Instruments ◽  
Deformation Characteristics ◽  
Compression Tests ◽  
Flow Forming ◽  
Community Forests ◽  
Flow Deformation ◽  
Dalbergia Melanoxylon

Abstract African blackwood (ABW: Dalbergia melanoxylon) is a valuable tree in Tanzanian local community forests, and heartwood has been mainly utilized as an irreplaceable material in musical instruments, e.g., clarinet, oboe and piccolo. Since its use is generally for the production of musical instruments only, most of the harvested volume is wasted due to defects that would affect the quality of final products. Wood flow forming can transform bulk woods into materials in temperature/pressure-controlled mold via plastic flow deformation. The main object of this study was to evaluate the deformation characteristics of ABW heartwood in developing the potential of wasted ABW parts in terms of the effective material use. The deformation characteristics of heartwood were examined by free compression tests. Specimens were compressed along the radial direction at 120 °C, and air-dried heartwood was dramatically deformed in the tangential direction. The plastic flow deformation of ABW was amplified by the presence of both extractives and moisture. In particular, the ethanol/benzene (1:2, v/v) soluble extractives in heartwood may have contributed to flow deformation. The results of the dynamic mechanical analysis showed that the air-dried heartwood exhibited softening in a temperature range over 50 °C. The ethanol/benzene-soluble extractives contributed to the softening behavior. The clarified deformation characteristics of ABW can contribute to more efficient material use of local forests.

Cutting Tool Wear and Mechanisms of Chip Formation During High-Speed Machining of Compacted Graphite Iron

2007 ◽  
Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Failure Criterion ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Compacted Graphite Iron ◽  
Crater Wear ◽  
Compacted Graphite ◽  
Cutting Speeds

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.

Deformation and strength properties of some rocks in southern Ontario

1979 ◽  
Vol 16 (1) ◽  
pp. 108-120 ◽  
Author(s):  
K. Y. Lo ◽  
M. Hori
Keyword(s):  
Deformation Behaviour ◽  
Strength Properties ◽  
Compression Tests ◽  
Underground Structures ◽  
Southern Ontario ◽  
Analysis And Design ◽  
Rock Types ◽  
Anisotropic Elastic ◽  
Geological Formations ◽  
Independent Parameters

Uniaxial compression tests were performed on sedimentary rocks of five different geological formations at various sites in southern Ontario. The deformation behaviour is analysed in terms of the cross-anisotropic elastic theory and typical sets of five independent parameters for each rock unit have been obtained. It is shown that some of the rock types are significantly anisotropic both in deformation and strength behaviour. The practical relevance of the results in the analysis and design of underground structures in these rocks is discussed.

scholarly journals Sixteen properties of Eucalyptus Tereticornis wood for structural uses

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Marta Cristina de Jesus Albuquerque Nogueira ◽  
Victor Almeida de Araujo ◽  
Juliano Souza Vasconcelos ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr
Keyword(s):  
Mechanical Properties ◽  
Decision Making ◽  
Shear Stress ◽  
Modulus Of Elasticity ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Eucalyptus Tereticornis ◽  
Moisture Contents ◽  
Through Diffusion ◽  
Standard Documents

Forest Red Gum eucalypt provides a versatile wood and is converted into different purposes. However, such wood is somewhat limited in structural ends, which highlights the need to exploit this gap through diffusion of mechanical properties of such timber. Obtained results should assist engineers and architects in decision-making for its best building application. This paper studied two physical and fourteen mechanical properties evaluation of Eucalyptus tereticornis at two different moisture contents, following the prescriptions of Brazilian (ABNT NBR 7190: 1997) and North American (ASTM D-143-14: 2014) standard documents. Thus, 1091 repeats were carried out for all properties. By a moisture reduction from 30% to 12%, the bulk density and eleven strength properties statistically showed changes such as modulus of rupture (static bending, parallel and perpendicular compressions), modulus of elasticity (perpendicular compression and static bending), shear stress, tangential cleavage, and parallel and perpendicular hardnesses. Then, the Eucalyptus tereticornis timber could be better usable if is further applied for structural construction uses.

Effect of Crystallographic Orientation on Nanoindentation Response of Fe3Si Single-Crystals

2018 ◽  
Vol 784 ◽  
pp. 44-48 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Aleš Materna
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Shear Stress ◽  
Contact Area ◽  
Measured Data ◽  
Deformation Mechanisms ◽  
Spherical Indentation ◽  
Indentation Modulus ◽  
Slip Systems ◽  
Correct Interpretation

Deformation mechanisms and mechanical properties of Fe3(wt.%)Si single crystal in two different orientations were investigated by spherical indentation. For correct interpretation of measured data and better understanding of the deformation mechanisms under the contact area, finite element simulations were carried out and resolved shear stress in available slip systems was computed. Pop-in behavior, differences in hardness, indentation modulus and shapes of residual imprints were observed and associated with different activation of slip.

scholarly journals Investigation into Performance of Multilayer Composite Nano-Structured Cr-CrN-(Cr0.35Ti0.40Al0.25)N Coating for Metal Cutting Tools

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 447 ◽  
Author(s):  
Sergey Grigoriev ◽  
Alexey Vereschaka ◽  
Alexander Metel ◽  
Nikolay Sitnikov ◽  
Filipp Milovich ◽  
...  
Keyword(s):  
Tool Life ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Constructional Steel ◽  
Wear Process ◽  
Layered Architecture ◽  
Process Pattern ◽  
Resistant Layer ◽  
Cutting Speeds

This paper deals with the Cr-CrN-(Cr0.35Ti0.40Al0.25)N coating. It has a three-layered architecture with a nano-structured wear-resistant layer. The studies involved the investigation into the microstructure (with the use of SEM and TEM), elemental and phase composition (XRD and SAED patterns), wear process pattern in scratch testing, crystal structure, as well as the microhardness of the coating. Cutting tests of tools with the above coating were carried out in dry turning of steel 1045 at cutting speeds of vc = 200, 250, and 300 m·min−1. The comparison included uncoated tools and tools with the commercial TiN and (Ti,Al)N coatings with the same thickness. The tool with the Cr-CrN-(Cr0.35Ti0.40Al0.25)N coating showed the longest tool life at all the cutting speeds under consideration. Meanwhile, a tool with the coating under study can be recommended for use in turning constructional steel at the cutting speed of vc = 250 m·min−1. At this cutting speed, a tool shows the combination of a rather long tool life and balanced wear process, without any threat of catastrophic wear.

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