The Wear of High Molecular Weight Polyethylene—Part II: The Effects of Reciprocating Motion, Orientation in the Polyethylene, and a Preliminary Study of the Wear of Polyethylene Against Itself

1982 ◽  
Vol 104 (1) ◽  
pp. 17-22 ◽  
Author(s):  
K. J. Brown ◽  
J. R. Atkinson ◽  
D. Dowson
Keyword(s):  
Molecular Weight ◽  
Stainless Steel ◽  
High Molecular Weight ◽  
Wear Surface ◽  
Wear Mechanisms ◽  
Molecular Orientation ◽  
Reciprocating Motion ◽  
Preliminary Study ◽  
Ultra High Molecular Weight

The wear of ultra-high molecular weight polyethylene against relatively smooth, dry stainless steel takes place by the same basic wear mechanisms whether unidirectional or reciprocating motion is used, but reciprocating motion produces slightly less wear overall. The effect of molecular orientation in the polyethylene has been studied and it has been shown that orientation perpendicular to the wearing surface is undesirable, whereas orientation parallel to the wear surface is mildly beneficial. The wear of polyethylene against itself is relatively severe and is largely determined by the temperatures reached by the rubbing surfaces.

scholarly journals A rugged, self-sterilizing antimicrobial copper coating on ultra-high molecular weight polyethylene: a preliminary study on the feasibility of an antimicrobial prosthetic joint material

2019 ◽  
Vol 7 (20) ◽  
pp. 3310-3318 ◽  
Author(s):  
Ke Wu ◽  
Samuel P. Douglas ◽  
Gaowei Wu ◽  
Alexander J. MacRobert ◽  
Elaine Allan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Copper Coating ◽  
Prosthetic Joint ◽  
Preliminary Study ◽  
First Time ◽  
Ultra High Molecular Weight ◽  
Joint Material

We report here for the first time how a copper coating bond to ultra-high molecular weight polyethylene (UHMWPE) via low temperature aerosol assisted chemical vapour deposition.

The Influence of Scratches to Metallic Counterfaces on the Wear of Ultra-High Molecular Weight Polyethylene

1995 ◽  
Vol 209 (4) ◽  
pp. 263-264 ◽  
Author(s):  
J Fisher ◽  
P Firkins ◽  
E A Reeves ◽  
J L Hailey ◽  
G H Isaac
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Average Surface Roughness ◽  
Reciprocating Motion ◽  
Roughness Measurement ◽  
Average Surface ◽  
Surface Roughness Measurement ◽  
Metallic Particles ◽  
Steel Surfaces ◽  
Ultra High Molecular Weight

A number of studies of explanted metallic femoral heads have shown scratches or damage caused by bone cement, bone or metallic particles. This damage has been cited as a cause of increased wear of ultra-high molecular weight polyethylene (UHMWPE) acetabular cups. In this laboratory study, small scratches 2 μm deep were made on smooth stainless steel surfaces at a spacing of 10 mm. These individual scratches were found to increase the wear rate of UHMWPE by a factor of 30 in unidirectional sliding and a factor of 70 in reciprocating motion. It is of particular concern that a single small scratch, which is not detected by the average surface roughness measurement Ra can cause such a dramatic increase in the wear of ultra-high molecular weight polyethylene.

The influence of concave dimples on the metallic counterface on the wear of ultra-high molecular weight polyethylene

2011 ◽  
Vol 226 (6) ◽  
pp. 455-462 ◽  
Author(s):  
Xincong Zhou ◽  
Alison L Galvin ◽  
Zhongmin Jin ◽  
Xinping Yan ◽  
J Fisher
Keyword(s):  
Molecular Weight ◽  
Surface Roughness ◽  
Stainless Steel ◽  
High Molecular Weight ◽  
Smooth Surface ◽  
High Nitrogen ◽  
Acetabular Cup ◽  
Reference Case ◽  
High Nitrogen Stainless Steel ◽  
Ultra High Molecular Weight

The aims of this study were to investigate how the dimples on a metallic counterface affect the wear rate of ultra-high molecular weight polyethylene (UHMWPE) in a multi-directional reciprocating pin-on-plate machine. The plates were high nitrogen stainless steel, representing the femoral head material. The pins used in this study were of ultra-high molecular weight polyethylene GUR 1120, which represents the material used in an acetabular cup. Three different cases were investigated: a smooth surface without dimples as a reference case, a surface with medium dimples with an average valley of 2.3 µm and a surface with large dimples with an average valley of 5.9 µm. It was found that all the dimples investigated did not improve the lubrication, but instead increased the surface roughness; consequently, the wear of UHWMPE was slightly increased.

The Wear of High Molecular Weight Polyethylene—Part I: The Wear of Isotropic Polyethylene Against Dry Stainless Steel in Unidirectional Motion

1978 ◽  
Vol 100 (2) ◽  
pp. 208-218 ◽  
Author(s):  
J. R. Atkinson ◽  
K. J. Brown ◽  
D. Dowson
Keyword(s):  
Molecular Weight ◽  
Stainless Steel ◽  
Steady State ◽  
Wear Rate ◽  
High Molecular Weight ◽  
Transfer Film ◽  
Fatigue Wear ◽  
Ultra High Molecular Weight ◽  
Sliding Distance ◽  
Unidirectional Motion

The wear of surgical grade ultra-high molecular weight polyethylene against stainless steel has been studied for unidirectional motion. After a short wearing-in period, two distinct steady-state regions appear on the wear graphs. In the first section adhesion is the predominant wear mechanism and a transfer film of polymer builds up on the steel counterface. After a certain sliding distance, determined by the load, the adhesive mechanism is augmented by fatigue wear and the wear rate increases sharply and remains constant at the new value.

Wear Mechanisms of Untreated and Gamma Irradiated Ultra-High Molecular Weight Polyethylene for Total Joint Replacements

2005 ◽  
Vol 127 (2) ◽  
pp. 273-279 ◽  
Author(s):  
J. Zhou ◽  
K. Komvopoulos
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Wear Mechanisms ◽  
Irradiation Dose ◽  
Cross Link ◽  
Link Density ◽  
Cross Link Density ◽  
Gamma Irradiated ◽  
Ultra High Molecular Weight

Modification of the surface microstructure of ultra-high molecular weight polyethylene (UHMWPE) is essential for improving the wear resistance of orthopedic implants. A common approach is to cross-link the polymer by gamma irradiation. The objective of this study was to examine the tribological behaviors of untreated and gamma irradiated UHMWPE under physiologically relevant contact conditions. Emphasis was placed on the identification of the dominant wear mechanisms in the early stage of polymer wear. The irradiation dose exhibited a strong effect on the tribological properties of UHMWPE sliding against Co–Cr alloy in a bath of bovine serum. Transmission electron microscopy (TEM) and environmental scanning electron microscopy (ESEM) were used to examine the microstructure and morphology of the worn surfaces. Regularly spaced folds with average spacing depending on the irradiation dose (i.e., cross-link density) formed on the wear tracks. Surface folding was related to plastic flow and the degree of mobility of the crystalline lamellae. SEM and TEM results elucidated the roles of the cross-link density and crystalline lamellae in the wear process. Based on the experimental evidence, a deformation model was obtained that provides explanation for the dependence of surface folding on the cross-link density and lamellae reorientation during sliding.

Tribological and Nanomechanical Properties of Unmodified and Crosslinked Ultra-High Molecular Weight Polyethylene for Total Joint Replacements

2004 ◽  
Vol 126 (2) ◽  
pp. 386-394 ◽  
Author(s):  
J. Zhou ◽  
A. Chakravartula ◽  
L. Pruitt ◽  
K. Komvopoulos
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Wear Mechanisms ◽  
Radiation Treatment ◽  
Adhesion Force ◽  
Joint Replacements ◽  
Wear Process ◽  
Total Joint Replacements ◽  
Nanomechanical Properties ◽  
Ultra High Molecular Weight

Wear of ultra-high molecular weight polyethylene (UHMWPE) continues to be a major obstacle limiting the longevity of total joint replacements. Efforts to solve the wear problem in UHMWPE have resulted in numerous studies dealing with the microstructure, morphology, and mechanical properties of this polymer. However, the fundamental wear mechanisms at different material length scales in total joint replacements remain elusive. Consequently, a systematic investigation of the initial stage of the wear process was performed in this study in order to obtain insight into the origins of wear in UHMWPE at submicrometer scales. Sliding experiments were performed with both unmodified and crosslinked (by gamma radiation treatment) UHMWPE subjected to reciprocating sliding against Co-Cr alloy in a bath of bovine serum under ranges of mean contact pressure and sliding speed typical of knee joints. Nanoindentation and optical, scanning electron, and transmission electron microscopy were used to examine the effect of crosslinking on the nanomechanical properties, dominant wear mechanisms, and microstructure of UHMWPE. The fundamental wear micromechanisms of unmodified and crosslinked UHMWPE are interpreted in the context of coefficient of friction, wear factor, creep, adhesion force, and microstructure results.

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