Wear Performance of GCr15 Friction Pairs with Effect of Initial Radial Micro-Grooves

2019 ◽  
Vol 11 (1) ◽  
pp. 56-61
Author(s):  
Wei Yuan ◽  
Shengkai Mei ◽  
Song Li ◽  
Zhiwen Wang ◽  
Jie Yu ◽  
...  

Background: Grooves may inevitably occur on the surface of the friction pair caused by severe wear or residual stress, which will play an important role on the reliability of machine parts during operation. Objective: The effect of the micro-grooves perpendicular to sliding direction on the wear performance of the friction pairs should be studied. Method: Micro-grooves can be machined on discs of friction pairs using electrical discharge machining. On-line visual ferrograph method was used to monitor the wear process to research the wear rate changing characteristic. Profilemeter and metallurgical microscope were used to observe the wear scars. Results: Comparing to the non-groove test, i) in one-groove test, wear volume and rate were approximate the same, and the wear scar was smooth, ii) when the grooves more than 4, the test running-in stage will be obviously prolonged, particularly for the test with 8 grooves on the disc, the duration of running-in stage is 4 times than that without grooves on specimen, and the wear rate and volume increase significantly, and then decrease with fluctuation, iii) the abrasive wear can be avoid with the debris stagnating in the groove, however, fatigue wear will significantly emerge. Conclusion: Abrasive wear can be avoided and smooth running-in surfaces can be obtained with proper amount of initial radial micro-grooves.

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 36 ◽  
Author(s):  
Muhammad Bhutta ◽  
Zulfiqar Khan ◽  
Nigel Garland

This article presents a wear study of Ni–Al2O3 nanocomposite coatings in comparison to uncoated steel contacts under reciprocating motion. A ball-on-flat type contact configuration has been used in this study in which a reciprocating flat steel sample has been used in a coated and uncoated state against a stationary steel ball under refrigerant lubrication. The next generation of environmentally friendly refrigerant HFE-7000 has been used itself as lubricant in this study without the influence of any external lubricant. The thermodynamic applications and performance of HFE-7000 is being studied worldwide, as it is replacing the previous generation of refrigerants. No work however has been previously performed to evaluate the wear performance of HFE-7000 using nanocomposite coatings. The wear scar developed on each of the flat and ball samples was studied using a Scanning Electron Microscope (SEM). The micrographs show that a combination of adhesive and abrasive wear occurs when using uncoated steel samples. Micro-delamination is observed in the case of Ni–Al2O3 nanocomposite coatings accompanied by adhesive and abrasive wear. Wear volume of the wear track was calculated using a White Light Interferometer. Energy-Dispersive X-ray Spectroscopic (EDS) analysis of the samples reveals fluorine and oxygen on the rubbing parts when tested using coated as well as uncoated samples. The formation of these fluorinated and oxygenated tribo-films helps to reduce wear and their formation is accelerated by increasing the refrigerant temperature. Ni–Al2O3 nanocomposite coatings show good wear performance at low and high loads in comparison to uncoated contacts. At intermediate loads the coated contacts resulted in increased wear, especially at low loads. This increase in wear is associated with the delamination of the coating and the slow formation of protective surface films under these testing conditions.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 660
Author(s):  
Qun Wang ◽  
Yingpeng Zhang ◽  
Xiang Ding ◽  
Shaoyi Wang ◽  
Chidambaram Seshadri Ramachandran

In order to investigate the effect of WC grain size on coatings’ properties and abrasive wear performance, a few WC-20Cr3C2-7Ni coatings with three different WC grain sizes were deposited by the high-velocity oxy-fuel (HVOF) thermal spray process. The phase compositions, microstructures, and mechanical properties of the coatings were investigated. Furthermore, the two- and three-body abrasive wear performances of the three coatings were tested by using SiC and SiO2 abrasives, respectively. The results show that all the three coatings were composed of WC, Cr3C2, and the Ni binder as well as the (W,Cr)2C phase. The abrasive wear resistance of the WC-20Cr3C2-7Ni coating monotonously increased with increasing WC grain size when the SiC abrasive was used in the two- and three-body abrasive wear tests. However, the wear resistance trend was reversed when the SiO2 abrasive was used in the three-body abrasive wear test. The specific wear rate of the WC-20Cr3C2-7Ni coating exposed to the SiC abrasive under the two-body abrasive wear test was the largest. The wear resistance of the coatings was more significantly affected by the hardness of the abrasive particles than the size of carbides present within the coating. The high hardness of SiC can cut both the carbide and the binder phase of the WC-based cermet coatings, resulting in a high wear rate, whereas the low hardness of SiO2 cuts and/or scratches the binder initially, and then it dislodges the carbides from the matrix. The dislodged carbides which were subsequently pulled out from the matrix by the repeated impact of the SiO2 abrasives result in a milder wear rate.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Peng Li ◽  
Xiya Huang ◽  
Dejun Kong

Purpose The purpose of this paper is to investigate the effects of load and speed on the corrosive wear performance of Al coating in 3.5% NaCl solution, which provided an experimental reference for the anti-corrosion engineering on offshore platforms. Design/methodology/approach A layer of Al coating was prepared on S355 steel using an arc spraying. The corrosive wear test was carried out with CFT–1 type surface property tester. The effects of load and speed on the corrosive wear performance of Al coating were investigated and the wear mechanism was also discussed. The electrochemical tests were conducted using a CHI660E type electrochemical workstation, the anti-corrosion mechanism was analyzed. Findings The average coefficient of frictions (COFs) of Al coating under loads of 1.5, 2.5 and 3.5 N are 0.745, 0.847 and 0.423, the wear mechanism is abrasive wear. The average COFs of Al coating at the speeds of 200, 400 and 600 rpm are 0.745, 0.878 and 0.617, respectively, the wear mechanism at the speeds of 200 and 400 rpm are abrasive wear, while that at the speed of 600 rpm is abrasive wear and fatigue wear. The anti-corrosion mechanism is the isolation of Cl– corrosion and cathodic protection of sacrificial anode. Originality/value This paper mainly studied corrosive wear and electrochemical corrosion performances of Al coating. This study hereby confirms that this manuscript is the original work and has not been published nor has it been submitted simultaneously elsewhere. This paper further confirms that all authors have checked the manuscript and have agreed to the submission.


2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Rajeev Namdeo ◽  
Sudhir Tiwari ◽  
Smita Manepatil

High stress (two-body) abrasive wear behavior of maleic anhydride grafted polyethylene (MA-g-PE) compatibilized ethylene and vinyl acetate copolymer (EVA)/high-density polyethylene (HDPE) polymer blend added with organophilic montmorillonite nanoclay in increasing quantity (0, 1, 2, 3, and 4 phr) has been evaluated in this study. Comparative volume losses and specific wear rates of polymer nanocomposites (PNCs) using two-body abrasion tester are discussed. Specific abrasive wear rate is optimized under different loads and sliding distances with different abrasive grade papers as per Taguchi L18 orthogonal array. Analysis of variance (ANOVA) is employed to determine the significance of factors influencing wear. Confirmation experiments are performed to predict and verify the improvement in observed values with the optimal combination level of control factors. It is observed that maximum wear volume loss and specific wear rate occur at 10 N load and 8 m sliding distance in all polymer nanocomposites. Scanning electron microscopy (SEM) images are used to analyze wear mechanisms under different experimental conditions.


2010 ◽  
Vol 113-116 ◽  
pp. 1930-1934
Author(s):  
Zhen Duo Han ◽  
Chao Qu ◽  
Yu Xing Peng ◽  
Guo An Chen ◽  
Yi Lei Li

A wear tester was developed. MC PA (nylon) filled with MoS2 and PU (polyurethane) were used as the material of the rubber wheel of roller guide shoes. Their wear performances was investigated with the tester. The results show that the wear rate of MC PA increases firstly and then decreases with increasing load, and reverses with increasing velocity. The wear rate of PU decreases firstly and then increases with increasing velocity. In addition, the main wear mechanisms of PU are plough wear and abrasive wear at the low load (200N). At the loads of 200N~500N, the main wear form of MC PA is the adhesive wear. Adhesive wear is the main mechanism of MC PA at the low velocity (3m/s). Due to inner heat accumulation by friction, squama-peering occurs on MC PA surface at the high velocity (8m/s). The dominant wear mechanisms of PU are abrasive wear and fatigue pitting. And the main reason of PU’s failure is the interior heat accumulation caused by friction.


2015 ◽  
Vol 766-767 ◽  
pp. 156-161
Author(s):  
S. Manoharan ◽  
G. Ramadoss ◽  
B. Suresha ◽  
R. Vijay

In the present study, enhancement of abrasion resistance of phenol formaldehyde (PF) resin based hybrid friction composites with different ingredients viz. binder, micron sized fibers and fillers have been synergistically investigated. Hybrid friction composites based on basalt and recycled aramid fibers were prepared using compression moulding. Three-body abrasive wear tests were conducted according to ASTM G-65 standard by dry sand/rubber wheel abrasion tester using two different size of angular silica sand abrasives (212 and 425 μm) at a constant load of 40 N. The results indicated that the wear volume loss increases with increasing abrading distance and abrasive particle size. However, the specific wear rate decreased with increasing abrading distance and increases with increase in abrasive particle size. Addition of fiber content has a significant influence on the abrasive wear performance of these composites. Further, the worn surfaces were examined by scanning electron microscopy to identify the involved wear mechanisms.


2021 ◽  
Author(s):  
Qin Zhou ◽  
Shuaishuai Li ◽  
Kai Zhang ◽  
Kun Qin ◽  
Minghao Lv ◽  
...  

Abstract Abrasive wear resulting from the microclastic rock is a common failure phenomenon in the drilling environmentthat often limits the sealing ability and the service life of seals. In this study, the friction and wear process of fluoro rubber (FKM) seals against 304 stainless steel (SS304) after one single entry of SiO2 abrasives were investigated. The influence of the changes in particle state on friction coefficient evolution, wear loss evolution, wear morphologies and wear mechanisms were discussed in detail. The results indicate that the presence of abrasive particles dispersed between the sealing interface clearly improves the friction performance of the seal pairs and deteriorates the wear performance of the metal counterpart. The movement and breakage of particles after one single entering into the sealing interface were obtained. And on this basis, the stable wear process can be divided into three stages. In addition, the main causes contributed to this change of wear mechanisms are the random movement and process of continuous breakdown of abrasive particles. Furthermore, the transition of the wear mechanism that clearly describes the wearing behavior of the seal pairs under these abrasive wear conditions was identified. The results of this study enhanced our understanding of the abrasive wear degradation of rubber seal in practical drilling applications.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4009
Author(s):  
Yingchao Pei ◽  
Dianxiu Xia ◽  
Shouren Wang ◽  
Liang Cong ◽  
Xuelin Wang ◽  
...  

An investigation on the tribological properties of GCr15 sliding against NM600 was carried out using a high-temperature friction and wear tester. As the temperature rose from room temperature to 300 °C, the average friction coefficient of NM600 increased rapidly, then decreased rapidly, and then became stable. The wear volume and specific wear rate of NM600 increased rapidly, then decreased rapidly, and then increased slowly. The wear mechanism and matrix properties of the tested steel at different temperatures are the main reasons for the above results. At 20–50 °C, the main wear mechanism was adhesive wear, fatigue wear, and abrasive wear. At 100–150 ℃, the wear mechanism was mainly adhesive wear, fatigue wear, abrasive wear, and oxidation wear. At 200–300 °C, the wear mechanism was mainly oxidation wear and abrasive wear.


Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 109 ◽  
Author(s):  
Haojun Wang ◽  
Tao Chen ◽  
Weilong Cong ◽  
Defu Liu

Ti-based ceramic coatings on Ti6Al4V substrates were successfully prepared through a laser cladding process using pre-placed starting materials of TiCN + SiO2 mixed powder without or with adding a 3 wt % CeO2 nanoparticles additive, aiming at improving the wear resistance of the Ti6Al4V alloy for biological applications. The effects of the CeO2 nanoparticles additive on the microstructure, microhardness, and wear performance of the coatings were analyzed in detail. The observations showed that the main compositions of the cladding coating were TiCN and TiN phase. Compared to the coatings without CeO2, the coatings modified with CeO2 nanoparticles led to more excellent mechanical properties. The average microhardness of the coatings modified with CeO2 nanoparticles was approximately 1230 HV0.2, and the wear volume loss of the coatings modified with CeO2 nanoparticles was approximately 14% less than that of the coatings without CeO2 under a simulated body fluid (SBF) lubrication environment. The major reasons included that the microstructure of the coatings modified with CeO2 nanoparticles was refined and compact granular crystalline. The wear mechanisms of the coatings were investigated from the worn surface of the coatings, wear debris, and the worn surface of the counter-body balls. The wear mechanisms of the coatings without CeO2 included abrasive wear, adhesive wear, and fatigue wear, while the wear mechanisms of the coatings modified with CeO2 nanoparticles included only abrasive wear and adhesive wear, because the fine microstructure of the coatings had an excellent resistance to fatigue wear.


2013 ◽  
Vol 739 ◽  
pp. 458-461
Author(s):  
W. Zhong ◽  
P. Chen ◽  
Y. Wang

Among the rail defects, the transverse fatigue crack, which has been the most dangerous damage, is developed near the rail running face and grows perpendicular to the rail surface. Finally, the transverse fatigue crack would result in the failure of railway rail. In this paper, the rolling tests were performed using a JD-1 wheel/rail simulation facility without any lubricant. The tester is composed of a small wheel served as rail and a larger wheel served as wheel. The fatigue behavior of rail rollers with different materials and curve radius were investigated in detail by examining wear volume and wear scar using optical microscopy (OM) and scanning electronic microscopy (SEM). The results indicate that with curve radius decreasing, the wear volume of rail roller increases rapidly and the fatigue damage becomes severe. Furthermore, the cracking propagation angle increases obviously with curve radius decreasing and fatigue wear is dominating during the wear process. There appears distinct plastic deformation on the section of rail roller under small curve radius condition. For the same curve radius, the wear volume of PD3 rail is more than that of PG4 rail and the plastic deformation is more obvious. Moreover, the cracking propagation angle of PD3 rail material is smaller than that of PG4 rail. In conclusion, PG4 rail material is not suitable for the high-speed railway.


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