الفهرس 
Chapter One Introduction And Literature SurveyOnly 14 pages are availabe for public view
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Abstract
There is a crucial role represented by the cervical human spine in limiting the physiological ranges of movement in the neck. However, when experiencing sudden loading such as in automotive crash and other situations can lead to a serious ligament damage and cause neck injury. Therefore, cervical fusion surgery is considered to have an outstanding result for this circumstance. despite numerous advantages of the traditional titanium alloy implants, these materials are associated with several limitations. The high rigidity and permanent existence of the metallic implant may lead to long term complications. High-density polyethylene HDPE is being considered in this field because its similarity with bone cartilage which will give it a huge advantage regarding biocompatibility and biomechanical sustainability at reduced stiffness. The presented approached aims to examine and investigate the integrity of HDPE composites reinforced by carbon fibers CF and Kevlar fibers KF fibers as alternative fusion arthroplasty.
the tribological behavior of cervical fusion plates was investigated and other biomechanical obstacles such as tension and fatigue that are stresses result from high and continuous neck movement. reciprocating wear machine was used to examine the tribological performance. It was found that the tested composites free of reinforcing fibers showed relatively higher wear values compared to composites reinforced by CF or KF. As the volume content of the tested fibers raised both coefficient of friction and wear decreased. Besides, composites reinforced by KF offered lower wear and Coefficient of friction values than that caused by composites reinforced by CF.
It seems that improvement in wear may be attributed to the strengthening effect of the tested fibers, where they withstand the shear and tensile stresses inside the matrix. Regarding mechanical performance, it was found that reinforcement fiber presence in HDPE for either CF or KF showed significant improvement for ultimate stress and elastic modulus of the tested composites. In case if fatigue, HDPE composite has also exhibited similar improvement especially with KF.