Improved hardness and wear properties of B-ion implanted polycarbonate

1992 ◽  
Vol 7 (7) ◽  
pp. 1900-1911 ◽  
Author(s):  
E.H. Lee ◽  
Gopal R. Rao ◽  
L.K. Mansur

Polycarbonate (Lexan) was implanted with 100 and 200 keV B+ ions to doses of 0.26, 0.78, and 2.6 × 1015 ions/cm2 at room temperature (<100 °C). Mechanical characterization of implanted materials was carried out by nanoindentation and sliding wear tests. The results showed that the hardness of implanted polycarbonate increased with increasing ion energy and dose, attaining hardness up to 3.2 GPa at a dose of 2.6 × 1015 ions/cm2 for 200 keV ions, which is more than 10 times that of the unimplanted polymer. Wear properties were characterized using a reciprocating tribometer with nylon, brass, and SAE 52100 Cr-steel balls with 0.5 and 1 N normal forces for 10000 cycles. The wear mode varied widely as a function of ion energy, dose, wear ball type, and normal load. For given ion energy, load, and ball type conditions, there was an optimum dose that produced the greatest wear resistance and lowest friction coefficient. For polycarbonate implanted with 0.78 × 1015 ions/cm2, the nylon ball produced no wear after 10000 cycles. Moreover, the overall friction coefficient was reduced by over 40% by implantation. The results suggest that the potential of ion-beam technology for improving polycarbonate is significant, and that surface-sensitive mechanical properties can be tailored to meet the requirements for applications demanding hardness, wear, and abrasion resistance.

1995 ◽  
Vol 117 (4) ◽  
pp. 569-574 ◽  
Author(s):  
Yasuhisa Ando ◽  
Yuichi Ishikawa ◽  
Tokio Kitahara

The friction coefficient and adhesion force between steel balls and flat test pieces were measured during friction under low normal load in order to examine the tribological characteristics. First, the friction coefficients were measured under a constant normal load of 0.8 to 2350 μN, and the adhesion forces were measured before and after each friction. The result showed that the friction coefficient was highest at low normal loads, while the friction force divided by the sum of the normal load and the mean adhesion force was almost constant over the whole range of loads. Second, when the normal load was reduced gradually during friction, friction still acted when the normal load became negative and a pulling off force was applied to the surface. Thus an adhesion force acts during friction and this adhesion force affects the friction force in the same way as the normal load.


2012 ◽  
Vol 220-223 ◽  
pp. 915-920
Author(s):  
Jeng Haur Horng ◽  
Jen Fin Lin ◽  
Shin Yuh Chern ◽  
Chin Chung Wei ◽  
Chun Yueh Chen

With the rapid development of microelectromechanical systems (MEMS) technology, materials such as silicon, metal, and polymers are widely used in the MEMS field. One of the reliability concerns related to Si MEMS is unwanted wear and adhesion. Therefore, SiC film is a possible choice for surfaces because of its favorable friction and wear properties such as used in cutting tool and transmission system of wind turbine. In this study, biocompatible SAM film (ODS) was used to decrease the adhesion force and the friction coefficient of SiC surface. Experimental results show that ODS can increase the contact angle and decrease the surface roughness value of SiC surfaces for the different roughness values and roughness directions. For Si, SiC film and SAMs film on surfaces, larger normal forces lead to smaller friction coefficients and cross roughness pattern have a smaller friction coefficient than that of straight roughness pattern. In addition, ODS film can decrease the friction coefficient on cross topography with relative small roughness value more effectively than can straight topography of SiC surfaces.


2015 ◽  
Vol 6 ◽  
pp. 820-830 ◽  
Author(s):  
Nikolay Podgaynyy ◽  
Sabine Wezisla ◽  
Christoph Molls ◽  
Shahid Iqbal ◽  
Helmut Baltruschat

Several transitions in the friction coefficient with increasing load are found on Au(111) in sulfuric acid electrolyte containing Cu ions when a monolayer (or submonolayer) of Cu is adsorbed. At the corresponding normal loads, a transition to double or multiple slips in stick–slip friction is observed. The stick length in this case corresponds to multiples of the lattice distance of the adsorbed sulfate, which is adsorbed in a √3 × √7 superstructure on the copper monolayer. Stick–slip behaviour for the copper monolayer as well as for 2/3 coverage can be observed at F N ≥ 15 nN. At this normal load, a change from a small to a large friction coefficient occurs. This leads to the interpretation that the tip penetrates the electrochemical double layer at this point. At the potential (or point) of zero charge (pzc), stick–slip resolution persists at all normal forces investigated.


1995 ◽  
Vol 117 (2) ◽  
pp. 244-249 ◽  
Author(s):  
C.-J. Lu ◽  
Zhaoguo Jiang ◽  
D. B. Bogy ◽  
T. Miyamoto

In a Lateral Force Microscope (LFM), appropriate spring constants of the tip assembly are essential for obtaining proper normal loads for wear or scratch tests and good lateral force signals. We developed a new tip assembly design for which the lateral and normal springs can be changed independently. It was installed on a LFM where two optical heads are used to detect the lateral and normal deflections of the tip assembly for simultaneous measurements of the surface topography and friction force. Reliable calibration procedures for the LFM are presented. The LFM was used to measure the lateral forces in wear tests under various normal forces for thin film magnetic disks with and without a carbon overcoat. The friction coefficient is constant in the load range where there is no wear and increases with normal load after the tip starts to damage the surface. The carbon-coated disk has a lower friction coefficient and can support larger normal loads without wear.


AIP Advances ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 065214
Author(s):  
Satyananda Kar ◽  
Bibhuti Bhusan Sahu ◽  
Hiroyuki Kousaka ◽  
Jeon Geon Han ◽  
Masaru Hori

2007 ◽  
Vol 353-358 ◽  
pp. 852-855 ◽  
Author(s):  
Yan Qiu Xia ◽  
Shinya Sasaki ◽  
Takashi Murakami ◽  
Miki Nakano

The friction and wear properties of phosphor bronze discs sliding against SAE52100 steel balls were evaluated using an Optimol SRV reciprocating friction and wear tester under the lubrication of pure poly-alpha-olefin (PAO) and PAO containing commercial phosphite ester, zinc dialkyldithiophosphate (ZDTP) and oleic acid additives. The morphologies of the worn surfaces of the phosphor bronze discs were observed using a scanning electron microscope (SEM). In addition, the elemental compositions and chemical states of several typical elements on the worn surfaces of the phosphor bronze discs were examined by means of X-ray photoelectron spectroscopy (XPS). The findings indicated that the phosphor bronze discs exhibited higher wear resistance under the lubrication of PAO containing phosphite ester than pure PAO, PAO containing ZDTP, and PAO containing oleic acid. Also, the phosphor bronze discs exhibited stable friction coefficients as low as 0.09-0.11 when lubricated with PAO containing phosphite ester. According to the XPS analyses, it was considered that the formation of CuO and phosphate led to lower friction coefficient and high wear resistance of phosphor bronze specimens lubricated with PAO containing phosphite ester. In the case of the phosphor bronze specimens lubricated with PAO containing ZDTP and oleic acid, the formation of organic compounds seemed to lead to lower friction coefficient, but did not seem to affect the wear resistance.


2014 ◽  
Vol 14 (04) ◽  
pp. 1450050 ◽  
Author(s):  
HONGYI FAN ◽  
SHANSHAN GAO ◽  
YANG LIU ◽  
ZHUOLI ZHU ◽  
HAIYANG YU

The relationships between the basic mechanical and wear properties of mottled enamel, especially during the mastication process, are important factors and must be explored. This study evaluated mottled enamel's micro-tribological behavior under artificial saliva conditions in vitro. The basic mechanical properties were determined by nanoindentiation testing. A conical diamond nanoindenter tip was used to scratch mottled enamel and normal enamel. The scratches were sliding with a constant normal load of 2 mN, with different cycles during the tests. The hardness, elastic modulus and friction coefficient were obtained to analyze the mechanical properties. The results showed that the hardness and elastic modulus of mottled enamel were 10% and 14.6% less, respectively, than those of normal enamel. Mottled enamel showed a lower friction coefficient and a higher wear rate, compared to normal enamel. The friction coefficient did not appear to be related to the wear rate for either type of enamel. The wear mechanism for normal enamel was plastic deformation for early wear, while the combination of plastic deformation and delamination was the main damage feature of mottled enamel.


1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.


1985 ◽  
Vol 55 ◽  
Author(s):  
J-P. Hirvonen ◽  
M. Nastasi ◽  
J. R. Phillips ◽  
J. W. Mayer

ABSTRACTMultilayered samples of Ti-Pd with linearly varying compositions were irradiated by Xe ions at 600 keV. The induced microstructures were studied by using transmission electron microscopy and Rutherford backscattering. Mixing was found to be complete over the entire composition range, resulting in amorphous or amorphous plus crystalline structures except at the palladium-rich end, where a crystalline Pd-Ti solid solution was obtained. This is consistent with the high equilibrium solubility of Ti in Pd. In addition, significant coarsening of the microstructure caused by irradiation was found in this solid solution region.Friction measurements were carried out in air and water by using a polytetrafluoroethylene pin as a counterpart. In air the friction coefficient was independent of composition and microstructure after about 2000 passes. In water, however, after 600 passes the friction coefficient reached a steady-state value with a pronounced minimum over the amorphous region. This property was unchanged throughout the remaining 10000 passes.


1996 ◽  
Vol 438 ◽  
Author(s):  
N. Tsubouchi ◽  
Y. Horino ◽  
B. Enders ◽  
A. Chayahara ◽  
A. Kinomura ◽  
...  

AbstractUsing a newly developed ion beam apparatus, PANDA (Positive And Negative ions Deposition Apparatus), carbon nitride films were prepared by simultaneous deposition of mass-analyzed low energy positive and negative ions such as C2-, N+, under ultra high vacuum conditions, in the order of 10−6 Pa on silicon wafer. The ion energy was varied from 50 to 400 eV. The film properties as a function of their beam energy were evaluated by Rutherford Backscattering Spectrometry (RBS), Fourier Transform Infrared spectroscopy (FTIR) and Raman scattering. From the results, it is suggested that the C-N triple bond contents in films depends on nitrogen ion energy.


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