scholarly journals Characteristic Aspects of Metal Wear: Wear-Induced Wear Transition and Characteristics of Wear Track Profiles

2020 ◽  
Author(s):  
Naofumi Hiraoka
2006 ◽  
Vol 20 (25n27) ◽  
pp. 4401-4406 ◽  
Author(s):  
JUNG-BUK RYU ◽  
SEOCK-SAM KIM ◽  
YOUNG-HUN CHAE

In contact conditions of crane sheave steel materials against a wire rope the contact surface of the sheave generally metal wear. In this study. Alternating bending wear tests using the normalized low carbon cast steel were out under four kinds of applied loads, and rotation speeds at 28rpm. The wear characteristics, and wear mechanism map on the worn surfaces was examined. The results of this study indicate that the wear rate of the substrate depends on the diameter of the wire ropes. The wear mechanism of the substrate is characterized by fatigue wear, but it was the wear transition happened in number of contact cycle. The temperature variation of the substrate groove was measured at 52°C, in average. Also it has been affected the surface crack propagation occurs with a movement of hertz by thermal stress and a wear mechanisms map has been proposed.


2015 ◽  
Vol 773-774 ◽  
pp. 168-172
Author(s):  
D. Harun ◽  
D. Nalatambi ◽  
Ramdziah Md. Nasir ◽  
Abdul Latif Mohd Tobi

Reciprocating sliding wear test of uncoated titanium alloy, Ti-6Al-4V is investigated using pin-on-flat contact arrangement of Ti-6Al-4V/Ti-6Al-4V pair under variable number of cycles at low number of cycles. The worn surfaces of the titanium alloy specimens were analyzed with the use of optical microscope (2D and 3D OM) and Vickers Hardness analysis was carried on. The pattern of the wear scar characteristics determined and the finding at the end of wear track had been focus through the presence at the end of wear track. It is suggesting an evidence of plastic deformation with the increasing in hardness value. The increase in hardness value at the end of wear track indicates increase in the plastic deformation with increasing number of cycles.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Tim W. Rattay ◽  
Torsten Kluba ◽  
Ludger Schöls

AbstractA 53-year old male with a history of progressive visual impairment, hearing loss, peripheral neuropathy, poorly controlled diabetes mellitus, cardiomyopathy, and weight loss was referred to the rare disease center due to the suspicion of mitochondrial cytopathy. In line with mitochondrial dysfunction, lactate in CSF was increased. Genetic testing by whole-exome sequencing and mitochondrial DNA did not reveal a likely cause. The case remained unsolved until he developed pain in his right hip, where he had received total hip arthroplasty 12 years earlier. An orthopedic evaluation revealed substantial shrinkage of the head of the hip prosthesis. Due to metal-on-metal wear, debris chromium and cobalt levels in serum were massively increased and significantly improved with multisystemic impairment after exchanging the defective implant.


2017 ◽  
Vol 886 ◽  
pp. 69-73
Author(s):  
Myo Minn ◽  
Sylvie Castagne

Investigation of the tribological characteristics of Ti6Al4V (Ti64) was performed by using a pin-on-disc tribometer. Polymer composites composed of a polyester resin matrix and silica abrasives with two different particle sizes were used as the counterface pin material. The macro and micro surface features on the wear track in relation to different abrasive particle sizes were analyzed by using optical microscope and scanning electron microscope. The wear depth was monitored by utilizing surface profiler and the change in hardness of Ti64 was measured by using Vickers hardness tester before and after the test. The effect of sliding speeds on the coefficient of friction was also studied. During sliding against Ti64 substrate, the results showed lower coefficient of friction, smoother surface features, and lower wear rate for the case of the polymer composite pin with smaller silica particles size when compared to that of polymer composite pin with larger silica particles size. The higher sliding speed generated more wear debris, much deeper wear depth, and wider wear track on Ti64 substrate.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 146
Author(s):  
Antonio Celentano ◽  
Tami Yap ◽  
Giuseppe Pantaleo ◽  
Rita Paolini ◽  
Michael McCullough ◽  
...  

Rigenera® is a novel class-1 medical device that produces micro-grafts enriched of progenitors cells without ex vivo manipulation of donor tissues. The manufacturer’s protocol has been supported for a wide variety of clinical uses in the field of regenerative medicine. This study aimed to evaluate its potential use for in vitro cell models. Human primary oral fibroblasts were cultured under standard conditions and processed through Rigenera® over a time course of up to 5 min. Cell viability was assessed using a Trypan Blue exclusion test. It is possible to process fibroblasts through Rigenera® although an initial reduction of cell viability was observed. Additionally, debris was evident in the cell suspension of the processed samples. Scanning electron microscopy (SEM) microanalysis of the debris and electron energy-loss spectroscopy confirmed the presence of metal wear possibly due to the processing conditions used in this study. Interestingly, pore sizes within Rigeneracons® grids were found to range between 250–400 μm. This is the first report assessing the suitability of Rigenera® and Rigeneracons® for in vitro applications. Whilst Rigenera® workflow was found to be amenable to laboratory uses, our results strongly suggest that further research and development is necessary to support the utilization of this technology for enrichment of micro-graft derived cells and cell sorting in vitro.


2021 ◽  
pp. 1-17
Author(s):  
Partha Haldar ◽  
Alok Mukherjee ◽  
Tapas Kumar Bhattacharya ◽  
Nipu Modak

Abstract The present research is emphasized on the microscopic observation of post wear surface of nano TiO2 doped alumina ceramics to accesses wearing by promising image processing algorithms viz. entropy analysis, Sobel edge detection technique and entropy filtered image histogram analysis in relation to the extent of doping. The experimental results of specific wear rate showed an indicator with the extent of micro fracturing of grains, ploughing of materials and debris formation on the wear track after a long wear cycles in terms of entropy level, edge density index, entropy filtered image and the nature of histogram at different doping level. The lowest value of entropy level and edge density index is shown at the level of 1 wt.% TiO2 doped alumina ceramics due to the presence of low number of granularity and microfracture grains on the wear track causes the lowering of specific wear rate. The histogram of entropy filtered image for 1 wt.% doping is more uniformly distributed with the highest frequency and lowest skewness factor over a wide range of intensity values for 1 wt.% doping.


2018 ◽  
Vol 50 (3) ◽  
pp. 1162-1174 ◽  
Author(s):  
Jie Wan ◽  
Jingjing Qing ◽  
Mingzhi Xu
Keyword(s):  

2012 ◽  
Vol 715-716 ◽  
pp. 703-710
Author(s):  
W.M. Rainforth ◽  
P. Zeng ◽  
L. Ma

t is well known that alumina ceramics undergo a time dependent wear transition during sliding wear. The transition, which is associated with 1-2 orders of magnitude increase in specific wear rate, involves a change from mild wear to intergranular fracture. The transition is strongly grain size dependent, with the time to the transition decreasing with grain size. However, there is a minimum grain size that can be achieved in fully dense alumina using commercially viable processing. Alternative strategies for reducing grain size and increasing toughness are through the addition of a fine second phase, with SiC and ZrO2being the most promising. The resultant composite not only has finer grain size, but also exhibits additional toughening mechanisms. This paper reports on the microstructural control in alumina, zirconia toughened alumina and alumina-silicon carbide composites. The grain size and residual stress distribution are related to the damage accumulation mechanism that occur during frictional contact, in particular the surface specific dislocation activity.


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