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

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.

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2324
Author(s):  
Mirosław Szala ◽  
Dariusz Chocyk ◽  
Anna Skic ◽  
Mariusz Kamiński ◽  
Wojciech Macek ◽  
...  

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.


1991 ◽  
Vol 252 ◽  
Author(s):  
Beverly L. Giammara ◽  
James M. Williams ◽  
David J. Birch ◽  
Joanne J. Dobbins

ABSTRACTThe effects of nitrogen ion implantation of Ti-6AI-4V alloy on growth of Pseudomonas aeruginosa bacteria on surfaces of the alloy have been investigated. Results for ion implanted samples were compared with controls with similarly smoothly polished surfaces and with controls that had intentionally roughened surfaces. The test consisted of exposing sterile alloy samples to a microbiological broth, to which 24 hour-old cultures of Pseudomonas aeruginosa had been added. After bioassociation at normal temperature 37°C, bacteria adhering to the surface were fixed and treated with a new ruthenium tetroxide staining method, and quantified by use of scanning electron microscopy (SEM), back-scattered electron imaging and EDAX energy dispersive microanalysis. For smooth samples of the alloy, after a 12 hour growth period, the retained bacteria (revealed by the biologically incorporated ruthenium), decreased monotonically with nitrogen dose out to a total fluence of approximately 7 × 1017/cm2 in an affected depth of approximately 0.1500 μm. The SEM confirmed that the Pseudomonas aeruginosa adhered equally to control materials. The ruthenium studies revealed that the amount of bacterial adhesion is indirectly proportional to the nitrogen ion implantation of the titanium. The greater the percentage of nitrogen ion implantation in the titanium alloy, the less bacteria colonized the disk.


1981 ◽  
Vol 7 ◽  
Author(s):  
J.B. Pethica ◽  
W.C. Oliver

ABSTRACTTo measure the mechanical properties of ion implanted layers special microhardness tests with penetration depths less than 100 nm have been made. The results show that increases in hardness of up to 50 % may occur in a number of metals as a result of nitrogen ion implantation. Considerable carbon is also present in the implanted surfaces and when in the form of a distinct layer, may give an apparent softening of surfaces at high doses.


1981 ◽  
Vol 7 ◽  
Author(s):  
R. G. Vardiman ◽  
R. N. Bolster ◽  
I. L. Singer

ABSTRACTMartensite will form in austenitic 304 stainless steel when it is deformed. Transmission electron microscope studies show that nitrogen ion implantation causes a reversion of the martensite to austenite. Specimens containing martensite resulting from fine surface polishing and heavy rolling are examined. The transformation is shown not to occur because of temperature increases during implantation. The effect is related to recent wear results in 304 stainless steel.


1994 ◽  
Vol 116 (4) ◽  
pp. 870-876 ◽  
Author(s):  
R. Wei ◽  
B. Shogrin ◽  
P. J. Wilbur ◽  
O. Ozturk ◽  
D. L. Williamson ◽  
...  

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.


1985 ◽  
Vol 55 ◽  
Author(s):  
P. A. Higham

ABSTRACTIon Implantation is emerging as a specialized surface treatment method by which orthopaedic alloys can be doped in order to modify for corrision, fatigue and wear properties.In this paper alterations in the corrosion and fatigue resistance of 316LVM stainless steel and Ti 6A1-4V ELI titanium alloy are considered. The effect of various variables was investigated; ion species, flux, accelerating voltage.Changes in corrosion resistance were monitored by performing anodic polarization studies in deaerated 0.1M NaCi solution at 22°C. The most effective species were found to be tantalum and boron for improvements to stainless steel.Fatigue properties were investigated using a Wohler type rotating bend test. Preliminary results show that nitrogen ion implantation improved the fatigue life for the steel but not the titanium alloy. Indications were found to suggest that time since implantation affect the fatigue properties.


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