The effect of ion induced damage on the hardness, wear, and friction of zirconia

1990 ◽  
Vol 5 (2) ◽  
pp. 385-391 ◽  
Author(s):  
E. L. Fleischer ◽  
W. Hertl ◽  
T. L. Alford ◽  
P. Børgesen ◽  
J. W. Mayer

Microhardness measurements were carried out on ion implanted single crystal Y2O3 stabilized cubic ZrO2. Inert gas ions (Ne, Ar, Xe) and N, Si, Ti, and W were implanted up to fluences of 3 × 1017 ions/cm2. Implantation energies were selected to give equivalent ranges. Comparison of the Knoop microhardness values of ZrO2 implanted with various species over a range of fluences showed that the principal variable causing hardness changes is damage energy and not the ion fluence nor the ion species. For all implants studied, the hardness versus damage energy gives a unified plot. At low doses the hardness rises with increasing deposited damage energy to a value 15% higher than that of unimplanted zirconia. With additional damage the hardness drops to a value 15% lower than that of the unimplanted zirconia. Friction and wear measurements in a pin-on-disk assembly showed very different behavior for high dose versus unimplanted ZrO2. The unimplanted samples showed debris with an associated rise in friction. The implanted system showed much less debris and a constant value of friction even after 10 000 cycles.

1989 ◽  
Vol 157 ◽  
Author(s):  
E. L. Fleischer ◽  
W. Herd ◽  
T. L. Alford ◽  
P. Børgesen ◽  
P. Revesz ◽  
...  

ABSTRACTMicrohardness measurements were carried out on ion implanted single crystal Y2O3 stabilized cubic ZrO2. Ions were implanted up to fluences of 3×1017 ions/cm2. Comparison of the Knoop micro-hardness values of ZrO2 implanted with various species over a range of fluences showed that the principle variable causing hardness changes for inert ion implantation is damage energy and not the ion fluence nor the ion species. For shallow inert ion implants, the hardness versus damage energy gives a unified plot. Hardnesses rise with increasing deposited damage energy to a value 15% higher than that of unimplanted zirconia. With additional damage the hardness drops to a value 15% lower than that of the unimplanted zirconia. Deep implants showed 50% increases in hardness and significant fracture toughness increases.Friction and wear measurements of the shallow implants in a pin-on-disk assembly showed very different behavior for high dose versus unimplanted ZrO2. The unimplanted samples showed debris with an associated rise in friction. The implanted system showed much less debris and a constant value of friction even after 10,000 cycles.


1987 ◽  
Vol 2 (1) ◽  
pp. 107-116 ◽  
Author(s):  
H. G. Bohn ◽  
J. M. Williams ◽  
C. J. McHargue ◽  
G. M. Begun

The annealing behavior of ion-implanted α-SiC single crystal was determined for samples implanted with 62 keV 14N to doses of 5.5X1014/cm2 and 8.0X1016/cm2 and with 260 keV 52Cr to doses of 1.5X1014/cm2 and 1.0X1016/cm2. The high-dose samples formed amorphous surface layers to depths of 0.17 μm (N) and 0.28 μm (Cr), while for the low doses only highly damaged but not randomized regions were formed. The samples were isochronically annealed up to 1600°C, holding each temperature for 10 min. The remaining damage was analyzed by Rutherford backscattering of 2 MeV He+, Raman scattering, and electron channeling. About 15% of the width of the amorphous layers regrew cpitaxially from the underlying undamaged material up to 1500°C, above which the damage annealed rapidly in a narrow temperature interval. The damage in the crystalline samples annealed linearly with temperature and was unmeasurable above 1000°C.


2019 ◽  
Vol 6 (7) ◽  
pp. 190594 ◽  
Author(s):  
Honglong Wang ◽  
Yaping Sun ◽  
Jian Chu ◽  
Xu Wang ◽  
Ming Zhang

Intensive study on structure transformation of muscovite single crystal under high-dose γ -ray irradiation is essential for its use in irradiation detection and also beneficial for mechanism cognition on defect formation within a matrix of clay used in the disposal of high-level radioactive waste (HLRW). In this work, muscovite single crystal was irradiated with Co-60 γ ray in air at a dose rate of 54 Gy min −1 with doses of 0–1000 kGy. Then, structure transformation and mechanism were explored by Raman spectrum, Fourier-transform infrared spectrum, X-ray diffraction, thermogravimetric analysis, CA, scanning electron microscope and atomic force microscopy. The main results show that variations in the chemical/crystalline structure are dose-dependent. Low-dose irradiation sufficiently destroyed the structure, removing Si–OH, thus declining hydrophilicity. With dose increase up to 100 kGy, CA increased from 20° to 40°. Except for hydrophilicity variation, shrink occurred in the (004) lattice plane which later recovered; the variation range at 500 kGy irradiation was 0.5% close to 0.02 Å. The main mechanisms involved were framework break and H 2 O radiolysis. Framework break results in Si–OH removal and H 2 O radiolysis results in extra OH introduction. The extra introduced OH probably results in Si–OH bond regeneration, lattice plane shrink and recovered surface hydrophilicity. The importance of framework break and H 2 O radiolysis on structure transformation is dose-dependence. At low doses, framework break seems more important while at high doses H 2 O radiolysis is important. Generally, variations in the chemical structure and surface property are nonlinear and less at high doses. This indicates using the chemical structure or surface property variation to describe irradiation is correct at low doses but not at high doses. This finding is meaningful for realizing whether muscovite is suitable for detecting high-dose irradiation or not, and mechanism exploration is efficient for identifying the procedure for defect formation within the matrix of clay used in disposal HLRW in practice.


Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.


1973 ◽  
Vol 73 (4) ◽  
pp. 700-712 ◽  
Author(s):  
J. D. Bruce ◽  
X. Cofre ◽  
V. D. Ramirez

ABSTRACT On the day following delivery (day 1 of lactation) one abdominal mammary gland was implanted with oestrogen and the contralateral gland received an empty needle. At 2, 5 or 10 days of lactation the rats were anaesthetized with pentobarbital and the nipples of both abdominal glands were cannulated and their pressures recorded by means of transducers coupled to an amplifier and recording system. The normal mammary glands of 5-day lactating rats responded to very low doses of oxytocin (Syntocinon®, Sandoz) (5× 10−8 mU) with a rhythmic elevation in pressure. However, saline infusion also evoked a small rise in intra-mammary pressure. Earlier (2 days) and later (10 days) in lactation the responses were smaller. Oestrogen decreases significantly the milk ejection response to oxytocin, and the effect was maximal at day 10 of lactation. Histological observations confirmed the diminished reaction of the gland to oxytocin, since the milk was retained in the alveoli of rats bearing a mammary-oestrogen implant. A paradoxical rise in pressure was detected in normal as well as in oestrogen-implanted glands when the lowest dose of oxytocin was injected in lactating rats which had previously received a high dose of oxytocin (50 mU or 500 mU). These results reinforce the hypothesis that oestrogen alters the milk ejection response to oxytocin and that the mechanism is probably related to changes in the contractility of the myoepithelial cells.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1336
Author(s):  
Jorge Caessa ◽  
Todor Vuchkov ◽  
Talha Bin Yaqub ◽  
Albano Cavaleiro

Friction and wear contribute to high energetic losses that reduce the efficiency of mechanical systems. However, carbon alloyed transition metal dichalcogenide (TMD-C) coatings possess low friction coefficients in diverse environments and can self-adapt to various sliding conditions. Hence, in this investigation, a semi-industrial magnetron sputtering device, operated in direct current mode (DC), is utilized to deposit several molybdenum-selenium-carbon (Mo-Se-C) coatings with a carbon content up to 60 atomic % (at. %). Then, the carbon content influence on the final properties of the films is analysed using several structural, mechanical and tribological characterization techniques. With an increasing carbon content in the Mo-Se-C films, lower Se/Mo ratio, porosity and roughness appeared, while the hardness and compactness increased. Pin-on-disk (POD) experiments performed in humid air disclosed that the Mo-Se-C vs. nitrile butadiene rubber (NBR) friction is higher than Mo-Se-C vs. steel friction, and the coefficient of friction (CoF) is higher at 25 °C than at 200 °C, for both steel and NBR countersurfaces. In terms of wear, the Mo-Se-C coatings with 51 at. % C showed the lowest specific wear rates of all carbon content films when sliding against steel. The study shows the potential of TMD-based coatings for friction and wear reduction sliding against rubber.


2006 ◽  
Vol 100 (11) ◽  
pp. 113303 ◽  
Author(s):  
K. H. Bai ◽  
H. Y. Chang

1994 ◽  
Vol 9 (11) ◽  
pp. 2823-2838 ◽  
Author(s):  
B.K. Gupta ◽  
Bharat Bhushan ◽  
C. Capp ◽  
J.V. Coe

In previous studies, sublimed C60-rich fullerene films on silicon, when slid against a 52100 steel ball under dry conditions, have exhibited low coefficient of friction (∼0.12). Films with different purities can be produced by sublimation at different substrate temperatures. In this paper, effects of purity of fullerene films and ion implantation of the films with Ar ions on the friction and wear properties of sublimed fullerene films are reported. C60-rich films (called here films with high purity) exhibit low macroscale friction. An increased amount of C70 and impurities in the fullerene film determined using Raman and Fourier transform infrared (FTIR), increases its coefficient of friction. Microscale friction measurements using friction force microscopy also exhibited similar trends. Low coefficient of friction of sublimed C60-rich films on silicon is probably due to the formation of a tenacious transfer film of C60 molecules on the mating 52100 steel ball surface. Based on scanning tunneling microscopy (STM), transmission electron microscopy (TEM), and high resolution TEM (HRTEM), we found that fullerene films primarily consisted of C60 molecules in a fcc lattice structure. Nanoindenter was used to measure hardness and elastic modulus of the as-deposited films. Ion-implantation with 1 × 1016 Ar+ cm−2 reduced macroscale friction down to about 0.10 from 0.12 with an increase in wear life by a factor of 4; however, doses of 5 × 1016 ions cm−2 gave three times higher friction and poorer wear life; higher doses disintegrated the C60 molecules. Based on STM, TEM, Raman, FTIR, and laser desorption Fourier-transform ion cyclotron resonance mass spectrometer (LD/FT/ICR) studies, we found that the ion implantation with a dose of 1 × 1016 Ar+ cm−2 resulted in smoothening of the fullerene film surface probably by compacting clusters, but without disintegrating the C60 molecules. However, a high dose of 5 × 1016 Ar+ cm−2 damaged the C60 molecules, converting it to an amorphous carbon. Nanoindentation studies show that ion implantation with a dose of 1 × 1016 Ar+ cm−2 resulted in an increase in the hardness from about 1.2 to 4.0 GPa and in elastic modulus from about 70 to 75 GPa and modified the elastic-plastic deformation behavior.


2021 ◽  
pp. 36-40
Author(s):  
F.F. Yusubov

Tribotechnical indicators of environmentally friendly frictional composite materials with phenol-formaldehyde matrix are studied. Friction tests were carried out on a MMW-1 vertical tribometer according to the pin-on-disk scheme. Keywords: brake pads, composites, friction and wear, plasticizers, degradation, porosity. [email protected]


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