Friction Behavior of Poly (Vinyl Alcohol) Gel Against Stainless Steel Ball in Different Lubricant Media

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Yu-Song Pan ◽  
Dang-Sheng Xiong ◽  
Xiao-Lin Chen

The effects of different variables on the friction coefficient of poly(vinyl alcohol) (PVA) hydrogel and stainless steel ball counterpart were investigated by a ball-on-plate friction and wear tester. Factors included lubrication condition, sliding speed, diameter of stainless steel ball, and load. It is shown that the free water in PVA hydrogel has a good lubrication on the friction counterpart. The friction coefficients have little difference between dry and lubricated conditions during the initial test stage. With the time prolonged, friction coefficient of PVA hydrogel under dry condition sharply increased within a short time. Friction coefficient decreased with increasing sliding speed and diameter of stainless steel ball. The decrease in the friction coefficient in bovine serum was 55.38% while the sliding speed increased from 45rpmto225rpm. The friction coefficient increased as the load increased, and the effect was more conspicuous at low load region.

2007 ◽  
Vol 330-332 ◽  
pp. 1297-1300 ◽  
Author(s):  
Yu Song Pan ◽  
Dang Sheng Xiong ◽  
Xiao Lin Chen

Poly(vinyl alcohol) (PVA) hydrogel is a promising articular cartilage biomaterial. In this paper, the effects of different variable factors on the friction coefficient of Poly(vinyl alcohol) (PVA) hydrogel were investigated when sliding against stainless steel ball by ball-pan tribometer. Factors included lubrication condition, sliding speed, diameter of stainless steel ball, and load. It was shown that the free water in PVA hydrogel has an excellent lubrication on the counterparts. The friction coefficients have little difference between dry and lubricants lubrication condition at initial friction test. With the friction test time prolonged, friction coefficient of PVA hydrogel under dry condition increased rapidly. Friction coefficient decreased with the increase of sliding speed and the diameter of stainless steel ball, and increased with the increasing load. The rising rate of friction coefficient at low load region is obviously larger than that at high load region.


2014 ◽  
Vol 966-967 ◽  
pp. 80-86
Author(s):  
Varunee Premanond ◽  
Onnjira Diewwanit

The objective of this work is to investigate the tribological behavior between WC-Co cemented carbide and austenitic stainless steel under repeated rotation sliding. Influences of cobalt content of commercial grade cemented tungsten carbide on friction coefficient and material transfer phenomena have been explored. Three grades of commercial WC-Co cemented carbide with similar medium WC grain size were employed; WC-12Co, WC-14Co and WC-19Co. The average grain size were ranges between 0.85-1.1 μm and the hardness of about 86-88 HRA have been given by the material maker. The composition analysis and the average grain size of tungsten carbide have been rechecked. Furthermore, the carbide grain size distribution was recorded and the fracture toughness was calculated for each WC-Co grade. The experiments were carried out using ball on disk test. The ball was made from SUS304 grade and the disk was fabricated by 3 grades of WC-Co cemented carbide. The friction coefficient was measured under dry sliding. The characteristics of contact surfaces were explored on the ball as well as on the disk after tests to reveal the presence of a metallic transfer on the WC-Co cemented carbide disk and the wear scar on the ball. The measurement results of wear volume on the stainless steel ball disclosed that maximum wear rate was found from the stainless steel ball rub against WC-19Co tool material.


2016 ◽  
Vol 690 ◽  
pp. 28-32
Author(s):  
Jae Hwan Pee ◽  
Na Ri Lee ◽  
Geun Hee Kim ◽  
Yoo Jin Kim ◽  
Yoon Suk Oh ◽  
...  

Metal marking and scratching are related to surface roughness, hardness and toughness of glaze. To improve the glaze properties, frits were added in the traditional celadon glaze and reducing firing atmosphere was controlled. Surface roughness of celadon glaze was decreased with increasing the reducing agent content (LPG flowing rate) and increasing the frits content. Though hardness of glaze without frit was increased with increasing the reducing agent content, hardness of glaze with frit was not changed extremely with increasing the reducing agent content. To evaluate the metal marking and scratching resistance, wear resistance test was used with stainless steel ball. After wear test, many metal marks and wide scratching trace were observed in the traditional celadon glaze. However, a few metal mark and scratch were observed in the celadon glaze with frit. The friction coefficient of glaze in the wear test was strongly depended on the frit contents.


Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 71
Author(s):  
Takuro Taniguchi ◽  
Kenji Urayama

We investigated the linear dynamic viscoelasticity of dual cross-link (DC) poly(vinyl alcohol) (PVA) (DC-PVA) hydrogels with permanent and transient cross-links. The concentrations of incorporated borate ions to form transient cross-links in the DC-PVA hydrogels (CBIN) were determined by the azomethine-H method. The dynamic viscoelasticity of the DC-PVA hydrogel cannot be described by a simple sum of the dynamic viscoelasticity of the PVA gel with the same permanent cross-link concentration and the PVA aqueous solution with the same borate ion concentration (CB = CBIN) as in the DC-PVA gel. The DC-PVA hydrogel exhibited a considerably higher relaxation strength, indicating that the introduction of permanent cross-links into temporary networks increases the number of viscoelastic chains with finite relaxation times. In contrast, the relaxation frequency (ωc) (given by the frequency at the maximum of loss modulus) for the DC-PVA hydrogel was slightly lower but comparable to that for a dilute PVA solution with the same CB. This signifies that the relaxation dynamics of the DC-PVA hydrogels is essentially governed by the lifetime of an interchain transient cross-link (di-diol complex of boron). The effect of permanent cross-linking on the relaxation dynamics was observed in the finite broadening of the relaxation-time distribution in the long time region.


2020 ◽  
Vol 93 (9) ◽  
pp. 1074-1078 ◽  
Author(s):  
Yoshinari Sawama ◽  
Miki Niikawa ◽  
Kazuho Ban ◽  
Kwihwan Park ◽  
Shin-yo Aibara ◽  
...  

2005 ◽  
Vol 475-479 ◽  
pp. 1251-1254 ◽  
Author(s):  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Yang Zhou ◽  
Zhi Li Zhang ◽  
Shi Bo Li ◽  
...  

The friction behavior of a high-purity bulk titanium aluminum carbide (Ti3AlC2) material dryly sliding against low carbon steel was investigated. Tests were performed using a block-on-disk type high-speed friction tester under sliding speed of 20 m/s and 60 m/s, several normal pressures from 0.1 to 0.8 MPa. The results showed that the friction coefficient is as low as about 0.18 for sliding speed of 20 m/s and only 0.1 for 60 m/s, and that almost not changes with the normal pressure. The reason could be related with the presence of a surface layer on the friction surface. The layer was analyzed to consist of Ti, Al and Fe oxides, which played a lubricate part inducing the friction coefficient decrease on the friction surface.


Author(s):  
K. Nakashima ◽  
Y. Sawae ◽  
T. Murakami

Poly(vinyl alcohol) (PVA) hydrogel is a candidate material for artificial cartilage of joint prostheses. From previous researches [1–4] it is shown that the wear of PVA hydrogel depends on the concentration of proteins in lubricants. Therefore it is considered that the adsorbed film formation by protein of albumin or γ-globulin influences upon the wear grade of PVA hydrogel. The remaining film of proteins on the glass plate was observed in fluorescence microscope. The adsorption condition of albumin and γ-globulin was different. The adsorbed film with effective reduction of the wear showed cooperative stratification of albumin and γ-globulin, but the condition of increased the wear showed separation of albumin and γ-globulin. Consequently, to reduce the wear of PVA hydrogel, cooperative stratification layers are effective.


2014 ◽  
Author(s):  
James T. Lehner ◽  
Christopher A. Brown

Changes in abrasive particle size, shape, and sharpness are studied in multi-axis lapping of sealing regions of stainless steel ball valves. Twelve experimental runs, investigating changes in the abrasive particle as a function of lapping load and motion, are performed during lapping. The influence of changes in the lapping load and motion are investigated using design of experiments. Changes in the size, shape, and sharpness of the abrasive particle are influenced by the load and by the motion of the seats and balls of the valves. Combinations of lapping load and motions, as opposed to any individual variable, tend to dominate the influence on the changes in the abrasive particle.


2012 ◽  
Vol 134 (1) ◽  
Author(s):  
G. Y. Li ◽  
Z. Y. Wang ◽  
M. K. Lei

A single high-nitrogen face-centered-cubic (f.c.c.) phase (γN) layer formed on the plasma source nitrided AISI 316 austenitic stainless steel at a nitriding temperature of 450 °C for a nitriding time of 6 h. An approximately 17 μm-thick γN layer has a peak nitrogen concentration of about 20 at. %. Tribological properties of the γN phase layer on a ball-on-disk tribometer against an Si3N4 ceramic counterface under a normal load of 2 and 6 N with a sliding speed of 0.15 to 0.29 m/s were investigated by friction coefficient and specific wear rate measurement. Worn surface morphology and wear debris were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The microhardness of the γN phase layer on the nitrided stainless steel was measured as about 15.1 GPa. The change in the friction coefficient of the γN phase layer on the stainless steel was dependent on the applied normal load, which was associated with that in the specific wear rate. Under a lower normal load of 2 N, the lower specific wear rate of the γN phase layer with a sliding speed of 0.15 m/s was obtained as 2.8 × 10−6 mm3/N m with a friction coefficient of 0.60. Under a higher normal load of 6 N, the lower specific wear rate with a sliding speed of 0.29 m/s was 7.9 × 10−6 mm3/N m with a friction coefficient of 0.80. When the applied load increased from 2 to 6 N, a transition of the wear mechanisms from oxidative to abrasive wear was found, which was derived from the oxidation reaction and the h.c.p. martensite phase transformation of the γN phase during the wear tests, respectively.


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