Improvement of UHMWPE Properties for Bioimplants by Gamma Irradiation

2011 ◽  
Vol 700 ◽  
pp. 207-210
Author(s):  
Frantisek Cerny ◽  
Mohamed Ali Khalil Ibrahim ◽  
Jan Suchanek ◽  
Svatava Konvickova ◽  
Vladimir Jech ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Gamma Irradiation ◽  
Room Temperature ◽  
Mechanical Characteristics ◽  
Wear Behavior ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Original Material ◽  
Friction Behavior ◽  
Ultrahigh Molecular Weight ◽  
Temperature Radiation

The effect of gamma irradiation and subsequent thermal treatment on the wear resistance and friction behavior of ultrahigh molecular weight polyethylene (UHMWPE) has been studied. Irradiation of the polymer was performed using a 60Co γ-emitter at laboratory temperature. Radiation dose 50 kGy was applied. Some irradiated samples were thermally treated at 150˚C for period of 30 min. and then slowly cooled to room temperature. A linear reciprocating tribometer was used to investigate the wear behavior of UHMWPE against Co-Cr-Mo alloy. The tests have been performed in unlubrication conditions. An important increase in wear resistance of the modified UHMWPE in comparison with the original material was proved. Besides wear rate the selected mechanical characteristics (friction coefficient, Young’s modulus, yield strength, fracture strength, and hardness) of original and modified samples of UHMWPE have been determined.

Tribological properties of ultrahigh-molecular-weight polyethylene (UHMWPE) composites reinforced with different contents of glass and carbon fibers

2019 ◽  
Vol 71 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Yanzhen Wang ◽  
Zhongwei Yin
Keyword(s):  
Molecular Weight ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
High Performance ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Content Type ◽  
Ultrahigh Molecular Weight ◽  
Pin On Disc ◽  
Uhmwpe Composites ◽  
Uhmwpe Composite

PurposeThis purpose of this study was to investigate the effects of carbon fiber (CF) and/or glass fiber (GF) fillers on the tribological behaviors of ultrahigh-molecular-weight polyethylene (UHMWPE) composites to develop a high-performance water-lubricated journal bearing material.Design/methodology/approachTribological tests were conducted using a pin-on-disc tribometer using polished GCr15 steel pins against the UHMWPE composite discs under dry conditions with a contact pressure of 15 MPa and a sliding speed of 0.15 m/s. Scanning electron microscopy, laser 3D micro-imaging profile measurements and energy-dispersive X-ray spectrometry were used to analyze the morphologies and elemental distributions of the worn surfaces.FindingsThe results showed that hybrid CF and GF fillers effectively improved the wear resistance of the composites. The fiber fillers decreased the contact area, promoted transfer from the polymers and decreased the interlocking and plowing of material pairs, which contributed to the reduction of both the friction coefficient and the wear rate.Originality/valueThe UHMWPE composite containing 12.5 Wt.% CF and 12.5 Wt.% GF showed the best wear resistance of 2.61 × 10−5mm3/(N·m) and the lower friction coefficient of 0.12 under heavy loading. In addition, the fillers changed the worn surface morphology and the wear mechanism of the composites.

Microstructure, nano-mechanical characterization, and fretting wear behavior of plasma surface Cr-Nb alloying on γ-TiAl

2020 ◽  
pp. 135065012093983
Author(s):  
Dongbo Wei ◽  
Fengkun Li ◽  
Xiangfei Wei ◽  
Tomasz Liskiewicz ◽  
Krzysztof J Kubiak ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Behavior ◽  
Wear Test ◽  
Wear Scar ◽  
Fretting Wear ◽  
Friction Behavior ◽  
Plasma Surface ◽  
Nb Alloying

In this study, surface Cr-Nb alloying was realized on γ-TiAl using double glow plasma hollow cathode discharge technique. An inter-diffusion layer was generated under the surface, composed of Cr2Nb intermetallic compounds. After Cr-Nb alloying, the surface nanohardness of γ-TiAl increased from 5.65 to 11.61 GPa. The surface H/E and H3/E2 increased from 3.37 to 5.98 and from 0.64 to 4.15, respectively. Cr-Nb alloying and its effect on fretting wear were investigated. The surface treatment resulted in improved plastic deformation and fretting wear resistance of γ-TiAl. The fretting wear test showed that an average friction coefficient of γ-TiAl against Si3N4 ball was significantly decreased after Cr-Nb alloying. The fluctuation of friction coefficient during running-in stage was significantly improved. The friction behavior of both γ-TiAl before and after Cr-Nb alloying could be divided into distinctive stages including formation of debris, flaking, formation of crack, and delamination. It was observed that the high hardness, resistance to plastic deformation, and fatigue resistance of γ-TiAl after Cr-Nb alloying could inhibit the formation of debris and delamination during friction test. The fretting wear scar area and the maximum wear scar depth were decreased, indicating that the wear resistance of γ-TiAl has been greatly improved after Cr-Nb alloying. The results indicated that plasma surface Cr-Nb alloying is an effective way for improving the fretting wear resistance of γ-TiAl in aviation area.

Formation, Characterization, and Wear Behavior of Aluminide Coating on Mirrax® ESR Steel by Low-Temperature Aluminizing Process

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Tuba Yener ◽  
Azmi Erdogan ◽  
Mustafa Sabri Gök ◽  
Sakin Zeytin
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Low Temperature ◽  
Room Temperature ◽  
Wear Behavior ◽  
Aluminide Coating ◽  
Pure Aluminum ◽  
Dry Sliding Wear ◽  
Thickness Variation ◽  
Wear Tests

Abstract The aim of this study was to investigate the effect of low-temperature aluminizing process on the microstructure and dry sliding wear properties of Mirrax steel. Low-temperature aluminizing process was applied on Mirrax steel at 600, 650, and 700 °C for 2, 4, and 6 h. The packs for the process were prepared using pure aluminum powder as aluminum deposition source. Ammonium chloride NH4Cl and Seydisehir Al2O3 powder were used as the activator and the inert filler, respectively. Scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis were applied for characterization of the coating surfaces. The through-thickness variation in the layer microstructure was determined and it was found to vary between 1 µm and 45 µm which increased with higher process temperature and time. After the deposition process, the coating layer hardness increased to 1000 HVN, whereas the hardness of the matrix was 250 HVN. The wear tests were performed using a ball-on-disc tribometer under 5 N load at room temperature and 500 °C on aluminized and untreated Mirrax steel. In both room temperature and high-temperature wear tests, it was determined that the aluminizing process increased the wear resistance of Mirrax steel. Increasing aluminizing time and temperature also increased the wear resistance. The uncoated and thin-coated samples generally exhibited wear in the form of plastic deformation and adhesion related ruptures. A high degree of tribological layer was observed on the wear trace on samples with high coating thickness, especially in high-temperature tests. Therefore, the volume losses in these samples were induced by fatigue crack formation and delamination.

scholarly journals Improvement of High Temperature Wear Behavior of In-Situ Cr3C2-20 wt. % Ni Cermet by Adding Mo

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 682
Author(s):  
Liang Sun ◽  
Wenyan Zhai ◽  
Hui Dong ◽  
Yiran Wang ◽  
Lin He
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Wear Mechanism ◽  
Room Temperature ◽  
Wear Behavior ◽  
Ceramic Particle ◽  
High Temperature Wear ◽  
The Coefficient Of Friction ◽  
Mo Content

Cr3C2-Ni cermet is a kind of promising material especially for wear applications due to its excellent wear resistance. However, researches were mainly concentrated on the experiment condition of room temperature, besides high-temperature wear mechanism of the cermet would be utilized much potential applications and also lack of consideration. In present paper, the influence of Mo content on the high-temperature wear behavior of in-situ Cr3C2-20 wt. % Ni cermet was investigated systematically. The friction-wear experiment was carried out range from room temperature to 800 °C, while Al2O3 ceramic was set as the counterpart. According to experimental results, it is indicated that the coefficient of friction (COF) of friction pairs risen at the beginning of friction stage and then declined to constant, while the wear rate of Cr3C2-20 wt. % Ni cermet risen continuously along with temperature increased, which attributes to the converted wear mechanism generally from typical abrasive wear to severe oxidation and adhesive wear. Generally, the result of wear resistance was enhanced for 13.4% (at 400 °C) and 31.5% (at 800 °C) by adding 1 wt. % Mo. The in-situ newly formed (Cr, Mo)7C3 ceramic particle and the lubrication phase of MoO3 can effectively improve the wear resistance of Cr3C2-20 wt. % Ni cermet.

Investigation of thermochemical boriding effect on wear behavior of a GGG 50 quality as-cast ductile iron

2016 ◽  
Vol 68 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Harun Mindivan
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Ductile Iron ◽  
Room Temperature ◽  
Wear Behavior ◽  
Surface Hardness ◽  
Wear Test ◽  
Content Type ◽  
Pin On Disc ◽  
Cast Ductile Iron

Purpose This study aims to investigate the microstructure and the abrasive wear features of the untreated and pack borided GGG 50 quality ductile iron under various working temperatures. Design/methodology/approach GGG 50 quality as-cast ductile iron samples were pack borided in Ekabor II powder at 900°C for 3 h, followed by furnace cooling. Structural characterization was made by optical microscopy. Mechanical characterization was made by hardness and pin-on-disc wear test. Pin-on-disc test was conducted on a 240-mesh Al2O3 abrasive paper at various temperatures in between 25 and 450°C. Findings Room temperature abrasive wear resistance of the borided ductile iron increased with an increase in its surface hardness. High-temperature abrasive wear resistances of the borided ductile iron linearly decreased with an increase in test temperature. However, the untreated ductile iron exhibited relatively high resistance to abrasion at a temperature of 150°C. Originality/value This study can be a practical reference and offers insight into the effects of boriding process on the increase of room temperature wear resistance. However, above 150°C, the untreated ductile iron exhibited similar abrasive wear performance as compared to the borided ductile iron.

Effect of Hydrothermal Environments on the Erosion of Castable Refractories

1977 ◽  
Vol 99 (2) ◽  
pp. 143-146 ◽  
Author(s):  
S. M. Wiederhorn ◽  
E. R. Fuller ◽  
J. M. Bukowski ◽  
C. R. Robbins
Keyword(s):  
High Pressure ◽  
Wear Resistance ◽  
Room Temperature ◽  
Coal Gasification ◽  
Wear Behavior ◽  
Erosive Wear ◽  
Chemical Changes ◽  
High Pressure Steam ◽  
Pressure Steam ◽  
Hydrothermal Environments

Hydrothermal environments are expected to adversely affect the erosive resistance of castable refractories intended for use in high wear areas of coal gasification plants. The erosive wear behavior of two grades of refractories proposed for such use was studied at room temperature after exposure of the refractories to high-pressure steam. Wear occurs primarily in the cement phase that bonds the more wear-resistant aggregate. The wear resistance of the refractories depended on chemical interactions between the cement and the high pressure steam. Although chemical changes were observed to occur in both refractories, the wear resistance was found to decrease only in those cases for which the strength of the cement phase was substantially reduced.

scholarly journals Porous Ultrahigh Molecular Weight Polyethylene/Functionalized Activated Nanocarbon Composites with Improved Biocompatibility

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6065
Author(s):  
Wangxi Fan ◽  
Xiuqin Fu ◽  
Zefang Li ◽  
Junfei Ou ◽  
Zhou Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Biomedical Applications ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
In Vitro Experiments ◽  
Ultrahigh Molecular Weight ◽  
Uhmwpe Composite

Ultrahigh molecular weight polyethylene (UHMWPE) materials have been prevalent joint replacement materials for more than 45 years because of their excellent biocompatibility and wear resistance. In this study, functionalized activated nanocarbon (FANC) was prepared by grafting maleic anhydride polyethylene onto acid-treated activated nanocarbon. A novel porous UHMWPE composite was prepared by incorporating the appropriate amount of FANC and pore-forming agents during the hot-pressing process for medical UHMWPE powder. The experimental results showed that the best prepared porous UHMWPE/FANC exhibited appropriate tensile strength, porosity, and excellent hydrophilicity, with a contact angle of 65.9°. In vitro experiments showed that the porous UHMWPE/FANC had excellent biocompatibility, which is due to its porous structure and hydrophilicity caused by FANC. This study demonstrates the potential viability for our porous UHMWPE/FANC to be used as cartilage replacement material for biomedical applications.

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