The mechanical behavior of a passivating surface under potentiostatic control

1997 ◽  
Vol 12 (12) ◽  
pp. 3345-3353 ◽  
Author(s):  
D. F. Bahr ◽  
J. C. Nelson ◽  
N. I. Tymiak ◽  
W. W. Gerberich
Keyword(s):  
Plastic Deformation ◽  
Shear Strength ◽  
Sulfuric Acid ◽  
Material Removal ◽  
Iron Alloy ◽  
Thermally Grown Oxide ◽  
Silicon Single Crystal ◽  
Passive Films ◽  
Theoretical Shear Strength ◽  
Elastic Loading

Continuous microindentation has been carried out on an iron–3% silicon single crystal in 1 M sulfuric acid. The ability of the material to support elastic loading is directly linked to the presence of thermally grown oxide films and passive films applied through potentiostatic control of the sample. When the passive film is removed, either by chemical or electrochemical means, the iron alloy can no longer sustain pressures on the order of the theoretical shear strength of iron. Instead, the metal behaves in a traditional elastic-plastic manner when no film is present. The oxide film at the edges of the indentation can sustain applied tensile stresses up to 1.2 GPa prior to failure. Indentation in materials undergoing dissolution must account for the rate of material removal over the remote surface and the resulting plastic deformation around the contact of the indentation.

scholarly journals Estimate of theoretical shear strength of C60 single crystal by nanoindentation

2021 ◽  
Vol 56 (18) ◽  
pp. 10905-10914
Author(s):  
Sergey N. Dub ◽  
Cetin Haftaoglu ◽  
Vitaliy M. Kindrachuk
Keyword(s):  
Shear Strength ◽  
Single Crystal ◽  
Shear Stresses ◽  
Slip Systems ◽  
Berkovich Indenter ◽  
Element Analysis ◽  
Theoretical Shear Strength ◽  
Elastic Loading ◽  
Octahedral Slip ◽  
Realistic Geometry

AbstractThe onset of plasticity in a single crystal C60 fullerite was investigated by nanoindentation on the (111) crystallographic plane. The transition from elastic to plastic deformation in a contact was observed as pop-in events on loading curves. The respective resolved shear stresses were computed for the octahedral slip systems $$\langle{01}\overline{1}\rangle\left\{ {{111}} \right\}$$ ⟨ 01 1 ¯ ⟩ 111 , supposing that their activation resulted in the onset of plasticity. A finite element analysis was applied, which reproduced the elastic loading until the first pop-in, using a realistic geometry of the Berkovich indenter blunt tip. The obtained estimate of the C60 theoretical shear strength was about $${1}/{11}$$ 1 / 11 of the shear modulus on {111} planes. Graphical abstract

MAGNESIL-N

Alloy Digest ◽  
1975 ◽  
Vol 24 (7) ◽  
Keyword(s):  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Iron Alloy ◽  
Heat Treating ◽  
Rolling Plane ◽  
Silicon Iron

Abstract MAGNESIL-N is a non-oriented silicon-iron alloy of exceptional magnetic qualities designed for applications involving frequencies of 400 Hertz and higher. It has good permeability in all directions of the rolling plane, and is designed for either punched or sheared laminations with random flux disposition. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on forming and heat treating. Filing Code: Fe-53. Producer or source: Spang Industries Inc..

AMPCOLOY B-2

Alloy Digest ◽  
1977 ◽  
Vol 26 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Iron Alloy ◽  
Heat Treating ◽  
General Purpose ◽  
Good Resistance ◽  
Aluminum Iron ◽  
Copper Aluminum

Abstract AMPCOLOY B-2 is a copper-aluminum-iron alloy for general-purpose uses. It has good machinability, good hot-working characteristics and moderate strength. Its many uses include cams, gears, bushings, bearings, marine equipment and other applications requiring good resistance to corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: Cu-329. Producer or source: Ampco Metal Inc..

scholarly journals Slicing Ceramics on Material Removed by a Single Abrasive Particle

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4324
Author(s):  
Yao-Yang Tsai ◽  
Ming-Chang Wu ◽  
Yunn-Shiuan Liao ◽  
Chung-Chen Tsao ◽  
Chun-Yao Hsu
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Brittle Fracture ◽  
Material Removal ◽  
Equations Of Motion ◽  
Abrasive Particle ◽  
Brittle Materials ◽  
Machining Parameters ◽  
Wire Saw ◽  
Cutting Model

Multi-wire saw machining (MWSM) used for slicing hard-brittle materials in the semiconductor and photovoltaic industries is an important and efficient material removal process that uses free abrasives. The cutting model of single-wire saw machining (SWSM) is the basis of MWSM. The material removal mechanism of SWSM is more easily understood than MWSM. A mathematical model (includes brittle fracture and plastic deformation) is presented in this paper for SWSM ceramic with abrasives. This paper determines the effect of various machining parameters on the removal of hard-brittle materials. For brittle fracture of SWSM ceramics, the minimum strain energy density is used as a fracture criterion. For plastic deformation of SWSM ceramics, the material removal is calculated using equations of motion. Actual wire-sawing experiments are conducted to verify the results of the developed mathematical model. The theoretical results agree with experimental data and practical experience. From the developed mathematical model, brittle fracture plays a major role in material removal of SWSM ceramics. Wire speed (S) and working load (P) are positively correlated with material removal of SWSM ceramics. The coefficient of friction is low, a lateral crack, which propagates almost parallel to the working surface, leads to more brittle fracture and material removal is increased.

Theoretical shear strength and the onset of plasticity in nanodeformation of cubic boron nitride

2017 ◽  
Vol 39 (2) ◽  
pp. 88-98 ◽  
Author(s):  
S. N. Dub ◽  
I. A. Petrusha ◽  
V. M. Bushlya ◽  
T. Taniguchi ◽  
V. A. Belous ◽  
...  
Keyword(s):  
Shear Strength ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Theoretical Shear Strength

Semiconductive behavior of passive films formed on pure Cr and Fe–Cr alloys in sulfuric acid solution

2002 ◽  
Vol 47 (27) ◽  
pp. 4357-4366 ◽  
Author(s):  
Hiroaki Tsuchiya ◽  
Shinji Fujimoto ◽  
Osamu Chihara ◽  
Toshio Shibata
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Passive Films

Estimation of Material Removal by Profilometer Measurements in Mass Finishing

2014 ◽  
Vol 611-612 ◽  
pp. 615-622
Author(s):  
Luana Bottini ◽  
Alberto Boschetto ◽  
Francesco Veniali
Keyword(s):  
Plastic Deformation ◽  
Surface Modification ◽  
Surface Morphology ◽  
Process Parameters ◽  
Material Removal ◽  
Machining Process ◽  
Local Surface ◽  
Mass Finishing ◽  
Barrel Finishing ◽  
The Relationship

This paper presents a new procedure to estimate the material removal (MR) in such conditions or operations where small amount of material or wear occur. The monitoring of material removal is essential to understand the machining mechanisms of several processes such as super finishing ones. For example the study of some mass finishing (MF) operations, i. e. the barrel finishing (BF) and the spindle finishing (SF), have been always limited by the difficulty to measure the local surface modification. Thus there is no knowledge about the relationship between process parameters and obtainable surface quality. The procedure is based on profilometer measurements typically used to characterized local surface morphology. An algorithm automatically finds the most representative peak of the profile. The comparison between the Abbot-Firestone curves, related to peaks achieved in different condition, permits to measure the volume of material removed by the operation. This method overcomes the well-known problem to repositioning the instrument in the same place when the part is moved from machining process to measurement one. In the case of BF, experimental demonstrated the reliability of this methodology to provide the evolution of material removed as a function of working time. Moreover the graphical plot of the representative peak at different times gave important information about machining mechanism. In particular it allowed to verify assumptions regarding the plastic deformation and the peak cutting which takes place.

The behaviour of passive films on carbon steel in sulfuric acid solutions

1995 ◽  
Vol 383 (1-2) ◽  
pp. 99-104 ◽  
Author(s):  
Xingpeng Guo ◽  
Hiroshi Imaizumi ◽  
Koichi Katoh
Keyword(s):  
Sulfuric Acid ◽  
Carbon Steel ◽  
Passive Films ◽  
Acid Solutions ◽  
Sulfuric Acid Solutions

Energy considerations regarding yield points during indentation

1999 ◽  
Vol 14 (6) ◽  
pp. 2269-2275 ◽  
Author(s):  
D. F. Bahr ◽  
D. E. Wilson ◽  
D. A. Crowson
Keyword(s):  
Experimental Data ◽  
Plastic Deformation ◽  
Stress Field ◽  
Yield Point ◽  
Applied Stress ◽  
Iron Alloy ◽  
Dislocation Glide ◽  
Double Kink ◽  
Rapid Transition

Two experiments that probe the nature of the rapid transition from elastic to plastic deformation are described. The load, and therefore stress, at which this yield point occurs is shown to be relatively independent of temperature in an iron alloy. When stresses lower than those required to generate a yield point during loading are applied for times between seconds and minutes, yielding occurs while the sample is under an applied stress. The time to generate a yield point increases as the applied stress is decreased. The possibilities of dislocation glide loop nucleation, double kink nucleation, and dislocation breakaway from pinning points are examined. Only glide loop nucleation appears to match the experimental observations. Criteria based on the stress-volume requirements of glide loop nucleation and the stress field underneath an indenter are presented which qualitatively describe the experimental data.

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