ASSESSMENT OF ABRASIVE WEAR RATE FOR PTFE-BASED COMPOSITES IN COMBINATION WITH STEEL

Tribologia ◽  
2021 ◽  
Vol 296 (2) ◽  
pp. 29-35
Author(s):  
Magdalena Lemecha ◽  
Krzysztof Ligier ◽  
Jerzy Napiórkowski
Keyword(s):  
Wear Rate ◽  
Carbon Fibre ◽  
Abrasive Wear ◽  
Polymer Film ◽  
Contact Area ◽  
Glass Fibre ◽  
Volumetric Wear ◽  
Ptfe Composite ◽  
Test Materials ◽  
Ptfe Composites

This paper presents a study of the tribological wear rate for PTFE-based composites in combination with C45 steel. PTFE composites with the addition of glass fibre, bronze, carbon fibre, and graphite were selected for the study. Tribological tests were conducted in a roller-block combination over an expanded contact area with no lubrication, using an SMC-2 machine. The study assessed the mass and volumetric wear for the test materials and the wear rate index. The highest wear values were noted for the PTFE composite with the addition of bronze, while the lowest was for the PTFE composite with the addition of glass fibre. For all the test materials, the formation of a polymer film on the steel counter specimen was noted.

Tribological assessment of a flexible carbon-fibre-reinforced poly(ether—ether—ketone) acetabular cup articulating against an alumina femoral head

2008 ◽  
Vol 222 (3) ◽  
pp. 273-283 ◽  
Author(s):  
S C Scholes ◽  
I A Inman ◽  
A Unsworth ◽  
E Jones
Keyword(s):  
Wear Rate ◽  
Carbon Fibre ◽  
Acetabular Component ◽  
Volumetric Wear ◽  
Wear Rates ◽  
Lubrication Regime ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone ◽  
Ether Ketone ◽  
Low Wear

New material combinations have been introduced as the bearing surfaces of hip prostheses in an attempt to prolong their life by overcoming the problems of failure due to wear-particle-induced osteolysis. This will hopefully reduce the need for revision surgery. The study detailed here used a hip simulator to assess the volumetric wear rates of large-diameter carbon-fibre-reinforced pitch-based poly(ether—ether—ketone) (CFR-PEEK) acetabular cups articulating against alumina femoral heads. The joints were tested for 25×106 cycles. Friction tests were also performed on these joints to determine the lubrication regime under which they operate. The average volumetric wear rate of the CFR-PEEK acetabular component of 54 mm diameter was 1.16 mm3/106 cycles, compared with 38.6 mm3/106 cycles for an ultra-high-molecular-weight polyethylene acetabular component of 28 mm diameter worn against a ceramic head. This extremely low wear rate was sustained over 25×106 cycles (the equivalent of up to approximately 25 years in vivo). The frictional studies showed that the joints worked under the mixed—boundary lubrication regime. The low wear produced by these joints showed that this novel joint couple offers low wear rates and therefore may be an alternative material choice for the reduction of osteolysis.

scholarly journals Computational wear prediction of insert conformity and material on mobile-bearing unicompartmental knee arthroplasty

2019 ◽  
Vol 8 (11) ◽  
pp. 563-569 ◽  
Author(s):  
Yong-Gon Koh ◽  
Jin-Ah Lee ◽  
Hwa-Yong Lee ◽  
Hyo-Jeong Kim ◽  
Kyoung-Tak Kang
Keyword(s):  
Wear Rate ◽  
Contact Pressure ◽  
Knee Arthroplasty ◽  
Contact Area ◽  
Unicompartmental Knee Arthroplasty ◽  
Polyethylene Wear ◽  
Mobile Bearing ◽  
Volumetric Wear ◽  
Wear Performance ◽  
Unicompartmental Knee

Objectives Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty with isolated medial or lateral compartment osteoarthritis. However, polyethylene wear can significantly reduce the lifespan of UKA. Different bearing designs and materials for UKA have been developed to change the rate of polyethylene wear. Therefore, the objective of this study is to investigate the effect of insert conformity and material on the predicted wear in mobile-bearing UKA using a previously developed computational wear method. Methods Two different designs were tested with the same femoral component under identical kinematic input: anatomy mimetic design (AMD) and conforming design inserts with different conformity levels. The insert materials were standard or crosslinked ultra-high-molecular-weight polyethylene (UHMWPE). We evaluated the contact pressure, contact area, wear rate, wear depth, and volumetric wear under gait cycle loading conditions. Results Conforming design inserts had the lower contact pressure and larger contact area. However, they also had the higher wear rate and volumetric wear. The improved wear performance was found with AMD inserts. In addition, the computationally predicted volumetric wear of crosslinked UHMWPE inserts was less than half that of standard UHMWPE inserts. Conclusion Our results showed that increasing conformity may not be the sole predictor of wear performance; highly crosslinked mobile-bearing polyethylene inserts can also provide improvement in wear performance. These results provide improvements in design and materials to reduce wear in mobile-bearing UKA. Cite this article: Bone Joint Res 2019;8:563–569.

scholarly journals The Tribological and Sealing Properties of PFA Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Ye Sujuan ◽  
Yu Quan ◽  
Li Kunquan ◽  
Tan Feng ◽  
Fan Qing ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Carbon Fiber ◽  
Wear Rate ◽  
Glass Fiber ◽  
Vinyl Ether ◽  
Transfer Film ◽  
Test Rig ◽  
Wear Rates ◽  
Ptfe Composite ◽  
Ptfe Composites

The polytetrafluoroethylene (PTFE) and perfluoroalkoxyperfluoropropyl vinyl ether (PFA) composites were prepared using carbon fiber (CF) and glass fiber (GF) as fillers. The effects of these fillers on the tribological and sealing properties were investigated. The tribological and sealing properties of the composites were evaluated by a wear tester and a seal test rig. Results showed that the incorporation of CF and GF both improved the wear resistance with composites, approaching wear rates as low as 10−6 mm3/N·m and lowered the seal’s leakage of the PTFE/PFA composites. As described here, CF was more effective than GF in improving the wear rate. Notably, the wear rate of the PFA/CF composite is much less than that of the PTFE composites as the transfer film on the couple ring is much more unique, thick, smooth, and compact. The leakage of carbon fiber-filled PFA composite seal was lowered to 66% less than the traditional PTFE composite seals, which indicates better sealing properties.

Increasing in wear resistance of excavating machine elements

2020 ◽  
pp. 306-308
Author(s):  
V.S. Bochkov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Thermomechanical Treatment ◽  
Cold Work ◽  
Hadfield Steel ◽  
Outer Side ◽  
Viii And Ix ◽  
Machine Elements ◽  
The Impact

The relevance of the search for solutions to increase the wear resistance of bucket teeth of excavating machine type front shovel is analyzed. The reasons for the wear of the teeth are considered. It is determined that when excavating machines work for rocks of VIII and IX categories, impact-abrasive wear of the inner side of the teeth and abrasive external wear occurs. It is proved that the cold-work hardening of Hadfield steel (the teeth material), which occurs during the excavating machine teeth work in the rocks of VIII and IX categories, reduces the impact-abrasive wear rate on the inner side of the teeth and does not affect the abrasive wear of the outer. The methods for thermomechanical treatment of the outer side of the excavating machine tooth is proposed. It can increase the wear resistance of Hadfield steel (110G13L) up to 1.7 times and lead to the self-sharpening effect of the tooth due to equalization of the wear rate of the outer and inner parts of the tooth. The efficiency factor of thermomechanical treatment to reduce the of abrasive wear rate of Hadfield steel is experimentally proved.

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.

Tribological Properties of Calotropis Procera Natural Fiber Reinforced Hybrid Epoxy Composites

2019 ◽  
Vol 895 ◽  
pp. 45-51
Author(s):  
M.J. Raghu ◽  
Govardhan Goud
Keyword(s):  
Abrasive Wear ◽  
Glass Fibre ◽  
Sliding Wear ◽  
Natural Fiber ◽  
Wear Test ◽  
Calotropis Procera ◽  
Dry Sliding Wear ◽  
Wear Loss ◽  
Fiber Reinforced ◽  
Three Body

Natural fibers are widely used for reinforcement in polymer composite materials and proved to be effectively replacing synthetic fiber reinforced polymer composites to some extent in applications like domestic, automotive and lower end aerospace parts. The natural fiber reinforced composites are environment friendly, have high strength to weight ratio as well as specific strengths comparable with synthetic glass fiber reinforced composites. In the present work, hybrid epoxy composites were fabricated using calotropis procera and glass fibers as reinforcement by hand lay-up method. The fibre reinforcement in epoxy matrix was maintained at 20 wt%. In 20 wt% reinforcement of fibre, the content of calotropis procera and glass fibre were varied from 5, 10, 15 and 20 wt%. The dry sliding wear test as per ASTM G99 and three body abrasive wear test as per ASTM G65 were conducted to find the tribological properties by varying speed, load, distance and abrasive size. The hybrid composite having 5 wt% calotropis procera and 15 wt% glass fibre showed less wear loss in hybrid composites both in sliding wear test as well as in abrasive wear test which is comparable with 20 wt% glass fibre reinforced epoxy composite which marked very low wear loss. The SEM analysis was carried out to study the worn out surfaces of dry sliding wear test and three body abrasive wear test specimens.

Machining and Wear of High-Alumina Ceramics for Structural Applications

2009 ◽  
Vol 409 ◽  
pp. 137-144 ◽  
Author(s):  
Stojana Veskovic-Bukudur ◽  
Tanja Leban ◽  
Milan Ambrozic ◽  
Tomaž Kosmač
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Direct Relationship ◽  
Bending Strength ◽  
High Alumina ◽  
Alumina Ceramics ◽  
Large Area ◽  
Structural Applications ◽  
Worn Surfaces

The wear resistances of four standard-grade high-alumina ceramics were evaluated and related to their machining ability. Three of the material grades contained 96% of alumina and 4% of either calcium silicate, or magnesium silicate, or manganese titanate in the starting-powder composition. The nominal alumina content in the fourth material was 99.7%. The specimens were fabricated using a low-pressure injection-molding forming technique, followed by thermal de-binding and sintering. After sintering the four materials differ significantly in their grain size, bending strength and Vickers hardness. No direct relationship between the microstructural parameters and the mechanical properties was found, but there was a grain-size dependence of the surface finish after grinding under industrial conditions. The two silicate-containing ceramics exhibited considerably higher wear resistances than the two silicate-free ceramics, but no direct relationship between the abrasive wear rate during grinding and the cutting time was observed. The cutting ability represents a valuable material characteristic for industrial practice, but it should not be directly used for predicting the wear rate during grinding. Quantitative differences in the cutting time and abrasive wear rate were manifested in the different topographies of the worn surfaces. Cutting resulted in relatively large area fractions of plastically deformed surfaces, whereas pullouts dominated the worn surfaces after grinding.

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