Surface Slip Retardation by ion Implantation

1987 ◽  
Vol 93 ◽  
Author(s):  
W. S. Samipath ◽  
F. M. Kustas ◽  
R. Wei ◽  
P. J. Wilbur
Keyword(s):  
Stainless Steel ◽  
Ion Implantation ◽  
Slip Line ◽  
Line Formation ◽  
Simple Test ◽  
Near Surface ◽  
Ion Energy ◽  
Surface Slip ◽  
Current Densities ◽  
Nitrogen Ion

ABSTRACTIon implantation is shown to retard surface slip and thereby induce improvements in wear and fatigue resistance of metals. A simple test is described which can be used to study the effects of ion implantation in retarding motion of dislocations in the near-surface regions of metals. In this test, regions of annealed and etched surfaces of metals are masked and implanted with ions. The specimens are then deformed until significant plastic deformation is introduced and the slip-lines are observed under the microscope. Evidence of improved resistance to slip-line formation in nitrogen ion implanted surface regions is presented for copper, α-iron and 303 stainless steel. The test is shown to be a useful tool for comparing the effects of ion implantation conditions on surface slip retardation, since adjacent regions of the surface can be implanted to different conditions and the resistance to slip line formation in the different regions can be compared. For example, the resistance to slip line formation in 303 stainless steel was found to be greater in regions that were implanted at ultrahigh current densities (1500 μA/cm2) than in regions implanted at lower current densities (100 μA/cm2) to the same dose and at the same ion energy.

scholarly journals Effect of Nitrogen Ion Implantation on the Cavitation Erosion Resistance and Cobalt-Based Solid Solution Phase Transformations of HIPed Stellite 6

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2324
Author(s):  
Mirosław Szala ◽  
Dariusz Chocyk ◽  
Anna Skic ◽  
Mariusz Kamiński ◽  
Wojciech Macek ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Ion Implantation ◽  
Phase Transformations ◽  
Erosion Rate ◽  
Cavitation Erosion ◽  
Matrix Phase ◽  
Nitrogen Ion Implantation ◽  
Stellite 6 ◽  
Nitrogen Ion

From the wide range of engineering materials traditional Stellite 6 (cobalt alloy) exhibits excellent resistance to cavitation erosion (CE). Nonetheless, the influence of ion implantation of cobalt alloys on the CE behaviour has not been completely clarified by the literature. Thus, this work investigates the effect of nitrogen ion implantation (NII) of HIPed Stellite 6 on the improvement of resistance to CE. Finally, the cobalt-rich matrix phase transformations due to both NII and cavitation load were studied. The CE resistance of stellites ion-implanted by 120 keV N+ ions two fluences: 5 × 1016 cm−2 and 1 × 1017 cm−2 were comparatively analysed with the unimplanted stellite and AISI 304 stainless steel. CE tests were conducted according to ASTM G32 with stationary specimen method. Erosion rate curves and mean depth of erosion confirm that the nitrogen-implanted HIPed Stellite 6 two times exceeds the resistance to CE than unimplanted stellite, and has almost ten times higher CE reference than stainless steel. The X-ray diffraction (XRD) confirms that NII of HIPed Stellite 6 favours transformation of the ε(hcp) to γ(fcc) structure. Unimplanted stellite ε-rich matrix is less prone to plastic deformation than γ and consequently, increase of γ phase effectively holds carbides in cobalt matrix and prevents Cr7C3 debonding. This phenomenon elongates three times the CE incubation stage, slows erosion rate and mitigates the material loss. Metastable γ structure formed by ion implantation consumes the cavitation load for work-hardening and γ → ε martensitic transformation. In further CE stages, phases transform as for unimplanted alloy namely, the cavitation-inducted recovery process, removal of strain, dislocations resulting in increase of γ phase. The CE mechanism was investigated using a surface profilometer, atomic force microscopy, SEM-EDS and XRD. HIPed Stellite 6 wear behaviour relies on the plastic deformation of cobalt matrix, starting at Cr7C3/matrix interfaces. Once the Cr7C3 particles lose from the matrix restrain, they debond from matrix and are removed from the material. Carbides detachment creates cavitation pits which initiate cracks propagation through cobalt matrix, that leads to loss of matrix phase and as a result the CE proceeds with a detachment of massive chunk of materials.

scholarly journals A Study on the Wettability of Ion-Implanted Stainless and Bearing Steels

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 208 ◽  
Author(s):  
Xinchun Chen ◽  
Xuan Yin ◽  
Jie Jin
Keyword(s):  
Stainless Steel ◽  
Ion Implantation ◽  
Ion Beam ◽  
Bearing Steel ◽  
Contact Angles ◽  
Electrochemical Technique ◽  
Near Surface ◽  
Thermodynamic Stabilization ◽  
Deposition Processes ◽  
Surface Modified

To satisfy the harsh service demand of stainless steel and aviation bearing steel, the anticorrosion and wettability behaviors of 9Cr18 stainless steel and M50 bearing steel tailored by ion beam surface modification technology were experimentally investigated. By controlling the ion implantation (F+, N+, N+ + Ti+) or deposition processes, different surface-modified layers and ceramic layers or composite layers with both effects (ion implantation and deposition processes) were obtained on metal surfaces. The wettability was characterized by a contact angle instrument, and the thermodynamics stabilization of ion implantation-treated metals in corrosive solution was evaluated through an electrochemical technique. X-ray photoelectron spectroscopy (XPS) was employed for detecting the chemical bonding states of the implanted elements. The results indicated that ion implantation or deposition-induced surface-modified layers or coating layers could increase water contact angles, namely improving hydrophobicity as well as thermodynamic stabilization in corrosive medium. Meanwhile, wettability with lubricant oil was almost not changed. The implanted elements could induce the formation of new phases in the near-surface region of metals, and the wettability behaviors were closely related to the as-formed ceramic components and amorphous sublayer.

Wear and Friction of Nitrogen Ion Implanted Steel

1983 ◽  
Vol 105 (2) ◽  
pp. 239-244 ◽  
Author(s):  
J. A. Kirk ◽  
G. W. Egerton ◽  
B. D. Sartwell
Keyword(s):  
Stainless Steel ◽  
Ion Implantation ◽  
Wear Behavior ◽  
304 Stainless Steel ◽  
Nitrogen Ion Implantation ◽  
Wide Range ◽  
Wear And Friction ◽  
Nitrogen Ion ◽  
Contact Pressures ◽  
Ion Implanted

A pin on disk wear test apparatus was used to evaluate wear and friction properties for nitrogen ion implanted and non-ion implanted steel disks in the presence of a lubricant. Both AISI/1018 mild steel and 304 stainless steel were examined. Typical fluence levels for ion implantation were above 1017 ions/cm2. In this paper disk wear is measured directly by a Talysurf profilometer tracing of the disk wear scar. By varying the contact area of the pin it was possible to evaluate wear behavior of both unimplanted and implanted disks over a wide range of contact pressures. It is shown that stainless steel disk wear can be decreased by nitrogen ion implantation, provided that contact pressures remain less than the yield strength of the substrate material. No significant wear improvements were observed for 1018 steel. To evaluate improvements in hardness due to nitrogen ion implantation, very low penetration depth microhardness measurements were made and the indentation diagonals were measured in a scanning electron microscope. These results and their limitations are also presented.

scholarly journals Carbon, Nitrogen, and Oxygen Ion Implantation of Stainless Steel

1995 ◽  
Vol 396 ◽  
Author(s):  
D.J. Rej ◽  
N.V. Gavrilov ◽  
D. Emlin ◽  
I. Henins ◽  
K. Kern ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ion Implantation ◽  
Plasma Source ◽  
Beam Line ◽  
Ion Current ◽  
Concentration Profiles ◽  
Oxygen Ion ◽  
Plasma Source Ion Implantation ◽  
Current Densities ◽  
Oxygen Ion Implantation

AbstractIon implantation experiments of C, N and O into stainless steel have been performed with beam-line and plasma source ion implantation methods. Acceleration voltages are varied between 27 and 50 kV, with pulsed ion current densities between 1 and 10 mA/cm2. Implanted doses range from 0.5 to 3×1018cm-2, while workpiece temperatures are maintained between 25 and 800°C. The implant concentration profiles, microstructure and surface mechanical properties of the implanted materials are reported.

The Effects of Low-Energy-Nitrogen-Ion Implantation on the Tribological and Microstructural Characteristics of AISI 304 Stainless Steel

1994 ◽  
Vol 116 (4) ◽  
pp. 870-876 ◽  
Author(s):  
R. Wei ◽  
B. Shogrin ◽  
P. J. Wilbur ◽  
O. Ozturk ◽  
D. L. Williamson ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Plasma Nitriding ◽  
Low Energy ◽  
304 Stainless Steel ◽  
High Dose ◽  
Ion Energy ◽  
Wear Resistant ◽  
Nitrogen Ion

The effects of nitrogen implantation conditions (ion energy, dose rate, and processing time) on the thickness and wear behavior of N-rich layers produced on 304 stainless-steel surfaces are examined. Surfaces implanted at elevated temperatures (≈400°C) with 0.4 to 2 keV nitrogen ions at high dose rates (1.5 to 3.8 mA/cm2) are compared to surfaces implanted at higher energies (30 to 60 keV) and lower current densities (0.1 to 0.25 mA/cm2). The most wear-resistant surfaces are observed when the implanted-ion energy is near 1 keV and the dose is very large (> 2 × 1019 ions/cm2). Typically, surfaces implanted under these optimum conditions exhibit load-bearing capabilities at least 1000 times that of the untreated material. Some comparisons are also made to surfaces processed using conventional plasma-nitriding. Samples treated using either process have wear-resistant surface layers in which the nitrogen is in solid solution in the fcc phase. It is argued that the deep N migration (> 1 μm) that occurs under low-energy implantation conditions is due to thermal diffusion that is enhanced by a mechanism other than radiation-induced vacancy production.

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