ni-w coatings, compared to pure nanocrystalline ni, exhibit higher hardness and wear resistance. in some cases, these coatings are considered as environmental friendly alternatives for hard chromium coating. till now, most of ni-w coatings have been produced by direct current electrodeposition from alkaline baths. in this study square pulse current was used for deposition of ni-w precipitates f...

Wear particles in a hard disk drive may cause the head/disk interface to fail. We have experimentally investigated wear particle generation resulting from fretting wear between the dimple on the suspension and the gimbal spring. We have found that increasing the normal load as well as using a low friction coating reduces the formation of wear particles. INTRODUCTION Examination of failed hard d...

A technique to analyze particulates extracted from inline jet engine oil filters using energy dispersive X-ray fluorescence (EDXRF) is presented. This technique, developed by the U.S. Department of Defense’s Joint Oil Analysis Technical Support Center (JOAP-TSC), is termed filter debris analysis (FDA). Six beta prototype instruments capable of performing FDA-EDXRF in an automated mode were manu...

OBJECTIVES Wear debris released from bearing surfaces has been shown to provoke negative immune responses in the recipient. Excessive wear has been linked to early failure of prostheses. Analysis using coordinate measuring machines (CMMs) can provide estimates of total volumetric material loss of explanted prostheses and can help to understand device failure. The accuracy of volumetric testing ...

A new Stratified Approach For Enhanced Reliability (SAFER) pre-clinical simulation testing of joint prostheses has been described in a preceding paper in this volume. The application of SAFER in vitro simulation and testing to metal-on-metal bearings is described in this review paper. The review aims to provide further understanding of the reasons for, and causes of, increased wear in metal-on-...

In this study, small fraction of NiTi (5 wt%) was added to Yttria stabilized zirconia (YSZ) top coat to improve it sliding wear resistance. The measurement of width of wear tracks after wear tests under a 15 N load for 100 m sliding distances showed that the width of wear track in NiTi-YSZ coating is shorter than that in YSZ coating which depicts the higher wear resistance of NiTi-YSZ coa...

New bearing materials for total joint replacement have been explored as the need to improve longevity and enhance performance is driven by the changing demands of the patient demographic. Carbon-reinforced PEEK has demonstrated good wear characteristics in experimental wear simulation in both simple geometry pin-on-plate studies and in total hip joint replacement. Carbon reinforced PEEK CFR-PEE...

Many elements contribute to congestive heart failure: changes in perfusion, hemodynamic stresses, alterations in calcium metabolism, and dysregulation of cell signaling pathways. Intervention in these processes forms the basis for current heart failure therapies. Nevertheless, heart failure is primarily a disease of wear and tear; despite everything we know about cardiac physiology and the clin...

Introduction Metal-on-metal (MOM) total hip arthroplasty using large diameter femoral heads offer clinical advantages however the failure rates of these hips is unacceptably high. Retrieved hips have a wide range of wear rates of their bearing and taper surfaces and there is no agreement regarding the cause of failure. Detailed visual inspection is the first step in the forensic examination of ...

the aim of this research was to study the wear behavior of 42crmo4 steel/zro2 composite with 10 and 30 ppi performed ceramic and compare it with the un-reinforced steel under different applied loads. the composite specimens were obtained by pressureless infiltration of the melt into a preformed ceramic of zirconium oxide. the effect of applied load on the specimens wear behavior was studied by ...