The Influence of Ion Implantation on The Near-Surface Mechanical Properties of Ceramics

1990 ◽  
Vol 188 ◽  
Author(s):  
C. J. McHargue ◽  
M. E. O'Hern ◽  
D. L. Joslin

ABSTRACTIon implantation of ceramics such as Al2O3 and SiC may produce a highly damaged but crystalline surface layer or an amorphous surface. The specific structure depends upon the implantation parameters. Studies using microindentation techniques show that a crystalline implanted surface has a higher hardness (by 10 to 50%) than the corresponding unimplanted crystal but the elastic modulus is essentially unchanged. The hardness and elastic modulus of amorphous implanted surfaces are less than those of the crystalline material. Estimates of the residual stress have been obtained from microindentation tests.

1996 ◽  
Vol 444 ◽  
Author(s):  
S. M. Myers ◽  
D. M. Follstaedt ◽  
J. A. Knapp ◽  
T. R. Christenson

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.


Author(s):  
V. V. Privezentsev ◽  
V. S. Kulikauskas ◽  
V. V. Zatekin ◽  
N. Yu. Tabachkova ◽  
S. V. Ksenich

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 427 ◽  
Author(s):  
Jie Jin ◽  
Wei Wang ◽  
Xinchun Chen

In this study, Ti + N ion implantation was used as a surface modification method for surface hardening and friction-reducing properties of Cronidur30 bearing steel. The structural modification and newly-formed ceramic phases induced by the ion implantation processes were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and grazing incidence X-ray diffraction (GIXRD). The mechanical properties of the samples were tested by nanoindentation and friction experiments. The surface nanohardness was also improved significantly, changing from ~10.5 GPa (pristine substrate) to ~14.2 GPa (Ti + N implanted sample). The friction coefficient of Ti + N ion implanted samples was greatly reduced before failure, which is less than one third of pristine samples. Furthermore, the TEM analyses confirmed a trilamellar structure at the near-surface region, in which amorphous/ceramic nanocrystalline phases were embedded into the implanted layers. The combined structural modification and hardening ceramic phases played a crucial role in improving surface properties, and the variations in these two factors determined the differences in the mechanical properties of the samples.


2004 ◽  
Vol 856 ◽  
Author(s):  
Alan K. Phillips ◽  
Robert B. Moore

ABSTRACTThe addition of small molecule fluorosurfactants to perfluorosulfonate ionomers has been found to have a profound effect on the morphology and mechanical properties of solution processed membranes. Perfluorooctane sulfonates neutralized with both alkali metal and alkylammonium counterions have been incorporated into solution processed Nafion® membranes. Sodium neutralized fluorosurfactants were found to crystallize during membrane casting leading to the formation of a surface layer of crystalline material.Tetramethylammonium neutralized surfactants behave in a similar fashion with crystallization of the surfactant occurring during casting. The use of large tetrabutylammonium counterions is found to prevent crystallization of the surfactant and create a highly plasticized membrane.


1983 ◽  
Vol 27 ◽  
Author(s):  
L. E. Pope ◽  
F. G. Yost ◽  
D. M. Follstaedt ◽  
S.T. Picraux ◽  
J. A. Knapp

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.


2004 ◽  
Vol 821 ◽  
Author(s):  
A. Karoui ◽  
G. Rozgonyi ◽  
T. Ciszek

AbstractThe effects of oxygen and nitrogen on the mechanical properties of Czochralski (CZ) and float zone silicon have been studied using nano-indentation. Nitrogen free FZ Si exhibited low hardness of 6.49 GPa and elastic modulus of 104 GPa. When doped with 2×1015cm−3 nitrogen, FZ Si hardness and elastic modulus increased to 8.2 and 182 GPa, respectively. In the near-surface denuded zone of N-doped CZ Si (N-CZ) the hardness correlates well with the O and N profiles. Distinct high hardness points, found in the O- and N- rich subsurface region, were attributed to precipitates. Nano-scratch tests of N-CZ Si confirmed the existence of hard phases, mostly small precipitates, whose density, estimated to be 2×1013cm−3, is in the range of previously suggested nuclei density in as-grown N-CZ silicon.


1983 ◽  
Vol 24 ◽  
Author(s):  
C. W. White ◽  
G. C. Farlow ◽  
H. Naramoto ◽  
C. J. Mchargue ◽  
B. R. Appleton

ABSTRACTPhysical and structural property changes resulting from ion implantation and thermal annealing of α-A12O3 are reviewed. Emphasis is placed on damage production during implantation, damage recovery during thermal annealing, and impurity incorporation during thermal annealing. Physical and structural property changes caused by ion implantation and annealing are correlated with changes in the mechanical properties.


2005 ◽  
Vol 475-479 ◽  
pp. 3959-3962 ◽  
Author(s):  
Sheng Zhi Hao ◽  
B. Gao ◽  
Ai Min Wu ◽  
Jian Xin Zou ◽  
Ying Qin ◽  
...  

High current pulsed electron beam (HCPEB) is now becoming a promising energetic source for the surface treatment of materials. When the concentrated electron flux transferring its energy into a very thin surface layer within a short pulse time, superfast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress field induced by an abrupt thermal distribution in the interactive zone impart surface layer with improved physicochemical and mechanical properties. The present paper reports mainly our experimental research work on this new-style technique. Investigations performed with a variety of constructional materials (aluminum, carbon and mold steel, magnesium alloys) have shown that the most pronounced changes of composition, microstructure and properties occur in the near-surface layers, while the thickness of the modified layer with improved mechanical properties (several hundreds of micrometers) is significantly greater than that of the heat-affected zone due to the propagation of stress wave. The surfaces treated with either simply several pulses of bombardment or complex techniques, such as rapid alloying by HCPEB can exhibit improved mechanical and physicochemical properties to some extent.


1995 ◽  
Vol 396 ◽  
Author(s):  
E. M. Hunt ◽  
J. M. Hampikian ◽  
D. B. Poker

AbstractIon implantation has been used to form nanocrystals in the near surface of single crystal A12O3. The ion fluence was 5 x 1016 Y+/cm2, and the implant energies investigated were 100, 150, and 170 keV. The morphology of the implanted region was investigated using transmission electron microscopy, x-ray energy dispersive spectroscopy, Rutherford backscattering spectroscopy and ion channeling. The implantation causes the formation of an amorphous surface layer which contains spherical nanosized crystals with a diameter of ∼13 nm. The nanocrystals are randomly oriented and exhibit a face-centered cubic structure with a lattice pmeter of ∼4.1 A ± .02 A. Preliminary chemical analysis shows that these nanocrystals are rich in aluminum and yttrium and poor in oxygen relative to the amorphous matrix.


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