Wear Reduction and Surface Layer Formation by a ZDDP Additive

1987 ◽  
Vol 109 (4) ◽  
pp. 577-586 ◽  
Author(s):  
Said Jahanmir
Keyword(s):  
Surface Layer ◽  
Surface Analysis ◽  
Iron Sulfide ◽  
Surface Deformation ◽  
Wear Behavior ◽  
Surface Films ◽  
Contact Loads ◽  
Order Of Magnitude ◽  
Sulfide Content ◽  
Wear Reduction

The results of wear tests and surface analyses confirmed that the wear behavior in the presence of ZDDP is controlled by chemically reacted surface films. Surface analysis by Auger microprobe showed that the reacted layer is composed of iron sulfide and zinc phosphate and that it extends to several hundred Å below the contact surface. It was found that the effectiveness of ZDDP in wear reduction was dependent on the test conditions. Under low loads and temperatures, it decreased wear by two orders of magnitude. However, at higher loads and temperatures, wear was increased by one order of magnitude. Scanning electron microscopy confirmed that at low loads, ZDDP changes the wear mechanism from plowing to a mild form of surface deformation, whereas at high loads plowing is changed to delamination of the surface layer. Surface analysis by Auger showed that higher loads and temperatures had resulted in reduction of sulfur content in the surface films. This reduction is attributed to changes in the reaction kinetics at higher contact temperatures caused by high contact loads and elevated oil temperatures. Since sulfides are usually harder than phosphates, the higher wear rate by delamination is explained by the loss of film strength due to reduction of sulfide content.

Coadsorption of bulky ions by surfactants. Monomolecular layers of tris(2,2'-bipyridyl)ruthenium(II) complex with sodium lauryl sulphate on glassy carbon, platinium, n-SnO2, and n-Si electrodes

1984 ◽  
Vol 49 (10) ◽  
pp. 2187-2196 ◽  
Author(s):  
Jan Lasovský ◽  
František Grambal ◽  
Miroslav Rypka
Keyword(s):  
Glassy Carbon ◽  
Complex Cation ◽  
Radiant Energy ◽  
Electric Energy ◽  
Sodium Lauryl Sulphate ◽  
Surface Films ◽  
Order Of Magnitude ◽  
Monomolecular Layers ◽  
Self Association ◽  
Semiconductor Electrodes

The electrochemical and photochemical behaviour of tris(2,2'-bipyridyl)ruthenium(II) complex (I) on glassy carbon, platinium, n-SnO2, and n-Si electrodes in the presence of sodium lauryl sulphate (II) was investigated. The surfactant in low concentrations induces self-association of the complex cation and its accumulation in the electrode-solution interface. At the optimum concentrations of sodium lauryl sulphate (cII ~0.6 mmol l-1) and of the complex (cI < 0.1 mmol l-1), monomolecular layers composed of I, II counterions are formed on the electrodes. The formation of the surface films does not depend on the kind of the electrode and improves the sensitivity of the voltammetric determination of I by as much as an order of magnitude. For the semiconductor electrodes, the surface films enhance the efficiency of conversion of radiant energy into electric energy. The effect under study may participate in the photosynthesis of green plants.

Friction and Wear Analysis of Deep Rolled and Vibrorolled Specimens in Lubricated Contact

2018 ◽  
Vol 767 ◽  
pp. 93-100
Author(s):  
Fritz Klocke ◽  
Anton Shirobokov ◽  
Rafael Hild ◽  
Andreas Feuerhack ◽  
Daniel Trauth ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Surface Treatment ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Shear Stresses ◽  
Deep Rolling ◽  
Microscopy Imaging ◽  
Friction And Wear Behavior ◽  
Wear Analysis

Deep rolling is an established mechanical surface treatment technology based on local plastic deformation of the surface layer. By these means, residual stresses, and strain hardening are induced into the surface layer as well as its surface structure is smoothed. Vibrorolling is a derivate technology of deep rolling characterized by sinusoidal rolling lanes. Due to process kinematics of vibrorolling the surface layer is incrementally deformed multiple times in different directions. As a result, a more intensive plastic deformation of the surface layer is achieved and potentially tribologically active surface structures are produced. To investigate and compare the effects of both surface treatment technologies on the tribological behavior of a processed component, a friction and wear analysis under lubricated conditions was conducted in this work. Friction and wear behavior of untreated, deep rolled, and vibrorolled specimens using a pin-on-cylinder tribometer was conducted. Hardness, roughness, and geometrical measurements of the wear traces were used to characterize the specimens. Additionally, qualitative assessments of the wear traces using scanning electron microscopy imaging were made. The measurements were performed before, during, and after the friction and wear analysis. Furthermore, contact forces between a tribometer pin and the workpiece were determined to analyze the development of contact shear stresses. Based on the conducted investigations, the effects of deep rolling and vibrorolling on the friction and wear behavior of the treated specimens are discussed and explanations for the observed phenomena are formulated in this work.

scholarly journals Hardening of Nickel Alloys by Ion Implantation of Titanium and Carbon

1996 ◽  
Vol 444 ◽  
Author(s):  
S. M. Myers ◽  
D. M. Follstaedt ◽  
J. A. Knapp ◽  
T. R. Christenson
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Surface Layer ◽  
Ion Implantation ◽  
Finite Element Modeling ◽  
Yield Stress ◽  
Nickel Alloys ◽  
Element Modeling ◽  
Order Of Magnitude ◽  
Amorphous Surface

AbstractDual ion implantation of titanium and carbon was shown to produce an amorphous surface layer in annealed bulk nickel, in electroformed Ni, and in electroformed Ni7 5Fe 2 5. Diamond-tip nanoindentation coupled with finite-element modeling quantified the elastic and plastic mechanical properties of the implanted region. The amorphized matrix, with a thickness of about 100 nm, has a yield stress of approximately 6 GP and an intrinsic hardness near 16 GPa, exceeding by an order of magnitude the corresponding values for annealed bulk Ni. Implications for micro-electromechanical systems are discussed.

scholarly journals The Corrosion Inhibition of AA6082 Aluminium Alloy by Certain Azoles in Chloride Solution: Electrochemistry and Surface Analysis

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 380 ◽  
Author(s):  
Klodian Xhanari ◽  
Matjaž Finšgar
Keyword(s):  
Surface Layer ◽  
Aluminium Alloy ◽  
Surface Analysis ◽  
Corrosion Inhibition ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Attenuated Total Reflectance ◽  
X Ray ◽  
Inhibition Effect ◽  
Secondary Ion

The corrosion inhibition effect of five azole compounds on the corrosion of an AA6082 aluminium alloy in 5 wt.% NaCl solution at 25 and 50 °C was investigated using weight loss and electrochemical measurements. Only 2-mercaptobenzothiazole (MBT) showed a corrosion inhibition effect at both temperatures and was further studied in detail, including with the addition of potassium iodide as a possible intensifier. Surface analysis of the MBT surface layer was performed by means of attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry techniques. The hydrophobicity of the MBT surface layer was also investigated.

Wear Assessment of Ti/SiC Surface Nano-Composite Layer and its Associated CP-Ti Substrate

2012 ◽  
Vol 445 ◽  
pp. 595-600 ◽  
Author(s):  
Ali Shamsipur ◽  
Seyed Farshid Kashani-Bozorg ◽  
Abbas Zarei Hanzaki
Keyword(s):  
Surface Layer ◽  
Wear Behavior ◽  
Composite Layer ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Micro Hardness ◽  
Wear Properties ◽  
Friction Stir ◽  
Pin On Disc ◽  
Cp Ti

In the present investigation, the surface of a commercially pure titanium (CP-Ti) substrate was modified to Ti/SiC nanocomposite layer employing friction stir processing technique; nanosized SiC powder was introduced into the stir zone provided by a rotating and advancing tool. The fabricated nanocomposite surface layer exhibited a micro hardness value of ~535HV which is much greater than 160HV of the substrate material using Vickers micro hardness testing. In addition, the un-treated CP-Ti substrate showed sever wear regime in the pin-on-disc test against the hardened AISI 52100 steel. It suffers extensive typical adhesive wear dominated by plastic deformation as evidenced by scanning electron microscopy. Also, deep grooves were formed, i.e. evidence of abrasive wear. Contrary to this, enhanced wear properties were detected for the Ti/SiC nanocomposite surface layer, i.e. lower coefficient of friction and weight loss. The nanocomposite surface layer was found to be adherent to the underlying substrate during the pin-on-disc test. The superior wear behavior of the nanocomposite surface layer is attributed to its improved micro hardness value due to the presence of hard nanosize SiC particles in a refined titanium matrix.

Friction and Wear Reduction of 440C Stainless Steel by Ion Implantation

1983 ◽  
Vol 27 ◽  
Author(s):  
L. E. Pope ◽  
F. G. Yost ◽  
D. M. Follstaedt ◽  
S.T. Picraux ◽  
J. A. Knapp
Keyword(s):  
Stainless Steel ◽  
Surface Layer ◽  
Yield Strength ◽  
Ion Implantation ◽  
Friction And Wear ◽  
No Reduction ◽  
Wear Reduction ◽  
Amorphous Surface ◽  
Wear Tests ◽  
Friction And Wear Tests

ABSTRACTFriction and wear tests on ion-implanted 440C stainless steel discs have been extended to high Hertzian stresses (≤ 3150 MPa). Implantation of 2 × 1015 Ti/mm2 (180–90 keV) and 2 × 1015 C/mm2 (30 keV) into 440C reduces friction (∼40%) and wear (> 80%) for Hertzian stresses as large as 2900 MPa, stresses which significantly exceed the yield strength of 440C (∼1840 MPa). Implantation of 4 × 1015 N/mm2 (50 keV) into 440C reduces friction slightly (∼25%) for Hertzian stresses > 1840 MPa but provides little or no reduction in wear. The amount of Ti remaining in the wear tracks correlates with the reductions in friction and wear. The implantation of Ti and C produces an amorphous surface layer which is believed to reduce friction and wear, whereas N implantation is expected to produce hard nitride particles which probably do not modify the hardness of 440C (KHN = 789) significantly.

Corrosion of Ti99.8-Pd Under Gamma Irradiation in MgC12-Rich Brine

1997 ◽  
Vol 506 ◽  
Author(s):  
E. Smailos ◽  
D. Schild ◽  
K. Gompper
Keyword(s):  
Surface Layer ◽  
Field Experiments ◽  
Surface Films ◽  
General Corrosion ◽  
Experimental Conditions ◽  
Test Conditions ◽  
Strong Candidate ◽  
Main Component ◽  
Container Material

ABSTRACTThe combined influence of gamma radiation (10 Gy/h) and high temperature (150 °C) on the corrosion of the promising HLW container material Ti99.8-Pd was investigated in an MgCl2-rich brine, and the corrosion surface films formed were characterized by XPS. For comparison, specimens without irradiation were also examined.Under the test conditions used, the alloy Ti99.8-Pd is resistant to local corrosion and its general corrosion is negligible low. The thin corrosion films formed on the surface of unirradiated specimens and in the crevices of specimens exposed to radiation consist of TiO2. However, outside the crevices of irradiated specimens, a surface layer consisting of Mg (main component of the brine) and Si (impurity in the brine) oxide is built up over the TiO2 layer. Comparable TiO2 layer thicknesses (30 - 65 nm, depending on the experimental conditions) are found for unirradiated and irradiated laboratory specimens. The TiO2 layer formed on the in-situ corrosion specimens (33 nm / 5.3 years) is thinner than that of the laboratory specimens (58 nm / 191 days) indicating less aggressive conditions in the field experiments. In view of these results, the alloy Ti99.8-Pd continues to be considered as a strong candidate container material and will be further investigated.

Technological Surface Layer Selection for Small Module Pitches of Gear Wheels Working under Cyclic Contact Loads

2006 ◽  
Vol 513 ◽  
pp. 69-74 ◽  
Author(s):  
Z. Gawroński ◽  
J. Sawicki
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Gear Wheel ◽  
X Ray ◽  
Fem Method ◽  
Contact Loads ◽  
Selection For ◽  
Gear Wheels ◽  
External Loads ◽  
Selection Of

Selection of proper technological surface layer well resistant to cyclic external loads superposed onto residual stresses is presented in this paper, with a gear wheel taken as an example. The computer simulations of external loads were carried out by means of the FEM method (Finite Element Method) with the use of the ANSYS package. Residual stresses were measured by means of the Waisman-Philips and modified X-ray sin2Ψ method. The results of the stress superposition were verified experimental by with use of a circulating power stand. The applied low pressure nitiriding method NITROVAC demonstrated a high ability to increase the durability and reliability of the discussed toothed wheel in comparison with the convencional treatment applied so far.

scholarly journals Quality improvement of calibrated steel by surface deformation. Part 1. Determination of the stressed state of cylinderical parts during orbital surface deformation

2020 ◽  
Vol 63 (10) ◽  
pp. 802-807
Author(s):  
S. A. Zaides ◽  
. Pham Van Anh
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Deformation Zone ◽  
Surface Deformation ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Machining Performance ◽  
Cylindrical Parts ◽  
Practice Methods ◽  
Hot Rolled

Cold drawn calibrated steel is an effective blank for the manufacture of low-rigid cylindrical parts such as shafts and axles. High accuracy of the diametric size along the length of the workpiece, low surface roughness, increased hardness and strength of the surface layer compared to hot rolled products allow us to produce a variety of parts with high metal utilization and high machining performance. The main disadvantage of calibrated metal is the residual stresses that occur during pressure treatment. To reduce or change the nature of the distribution over the cross section, it is proposed to use small plastic deformations in the surface layer of the hire. Known in practice methods of surface plastic deformation (PPD) usually lead to the curvature of non-rigid workpieces. To intensify the stress-strain state in the deformation zone, we propose a method of orbital surface deformation. Based on the finite element modeling, influence of the main parameters of orbital surface deformation on stress state in the deformation zone and residual stresses in the finished products is considered. Compared with the traditional PPD process, the stress intensity during orbital surface deformation will increase by 10 – 15 %. The residual compressive stresses that form in the surface layers reach 70 – 85 % of the material tensile strength. In the second part of the article, it is supposed to provide information on a more effective method of surface deformation and on the change in initial residual stresses that are formed during the calibration of cylindrical rods.

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