Tribological Properties of a New Alloy Laser Cladded on Hypereutectoid Rails

2021 ◽  
pp. 1-24
Author(s):  
Panahsadat Fasihi ◽  
Ralph Abrahams ◽  
Peter Mutton ◽  
Wenyi Yan
Keyword(s):  
Wear Rate ◽  
Laser Cladding ◽  
Tribological Properties ◽  
Surface Characterization ◽  
Rolling Contact ◽  
Test Machine ◽  
The Novel ◽  
Custom Made ◽  
Iron Based ◽  
Wear Modes

Abstract To overcome the previous limitations imposed by standard laser cladding alloys, a novel iron-based laser cladding alloy, SS415, is developed and investigated. The wear and rolling contact fatigue resistance properties of the novel SS415 laser cladded on a premium railway hypereutectoid rail is experimentally investigated using a custom-made roller-on-disc test machine. The obtained results are compared with our previously published results of non-clad rail and the standard iron-based cladding alloys, namely 410L and SS420, specimens under the same conditions. The accumulated wear rate and the pileup area was quantified with the aid of an optical profilometer. The obtained results were correlated to in-depth wear surface characterization using optical microscopic images. The experimental results showed that the novel SS415 exhibits favorable hardness variation, more ductile behavior, promising work-hardenability and a 95% reduction in the wear rate, in comparison to the non-cladded samples. Moreover, the SS415 cladding resulted in less surface damage and the lowest degree of third body abrasive wear modes, after the completion of the rolling contact cycles. Based on this investigation, the novel SS415 is a promising iron-based laser cladding alloy that offers the best wear and fatigue performance compared to both 410L and SS420 cladded samples. Additionally, this novel alloy offers significantly improved mechanical and tribological properties compared to the two standard alloys.

Effects of Elements Composition on Tribological Properties of PES/Metal Matrix Composite Materials

2013 ◽  
Vol 313-314 ◽  
pp. 188-192
Author(s):  
Zhi Gao Luo ◽  
Jin Li ◽  
Bing Zhao ◽  
Jian Wei Xu
Keyword(s):  
Composite Materials ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Tribological Properties ◽  
Metal Matrix ◽  
Friction And Wear ◽  
Plastic Layer ◽  
Test Machine

The friction and wear characteristics of PES/metal matrix composite materials were tested by the ball-disc friction pair of UMT-2 friction and wear test machine. The plastic layer is composed of distinct components. The results showed that: the tribological properties of PES/metal matrix composites were improved significantly after added 5wt % of the LCP. With the increasing of PTFE the PES/metal matrix composite material friction coefficient and wear rate were decreasing when the load of 10N and rotating speed of 400rmp. But the friction coefficient and wear rate increased when the mass fraction of PTFE more than 22 wt %. The tribological properties were the best when the PTFE content was 18 wt % to 25 wt % in the plastic layer.

scholarly journals Friction and Wear Performance of Staple Carbon Fabric-Reinforced Composites: Effects of Surface Topography

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 141 ◽  
Author(s):  
Chang-Mou Wu ◽  
Yi-Ching Cheng ◽  
Wen-You Lai ◽  
Po-Hsun Chen ◽  
Tzong-Der Way
Keyword(s):  
Wear Rate ◽  
Surface Topography ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Applied Pressure ◽  
Specific Wear Rate ◽  
Test Machine ◽  
Carbon Fabric ◽  
Sliding Speed ◽  
Resin Impregnation

Here, staple carbon fiber fabric-reinforced polycarbonate (PC)- and epoxy (EP)-based composites with different impregnating resin levels were fabricated using a modified film stacking process. The effects of surface topographies and resin types on the tribological properties of stable carbon fabric composites (sCFC) were investigated. Friction and wear tests on the carbon composites were conducted under unlubricated sliding using a disk-on-disk wear test machine. Experimental results showed that the coefficient of friction (COF) of the sCFC was dominated by matrix type, followed by peak material portion (Smr1) values, and finalized with core height (Sk) values. The COF of composites decreased by increasing the sliding speed and applied pressure. This also relied on surface topography and temperature generated at the worn surface. However, the specific wear rate was strongly affected by resin impregnation. Partially-impregnated composites showed lower specific wear rate, whereas fully-impregnated composites showed a higher wear rate. This substantially increased by increasing the sliding speed and applied pressure. Scanning electron microscopy observations of the worn surfaces revealed that the primary wear mechanisms were abrasion, adhesion, and fatigue for PC-based composites. For EP-based composites, this was primarily abrasion and fatigue. Results proved that partially-impregnated composites exhibited better tribological properties under severe conditions.

Microstructure and Tribological Properties of a Ni-Base Laser Cladding on Aluminum Bronze

2010 ◽  
Vol 160-162 ◽  
pp. 100-105
Author(s):  
Jian Lin Xu ◽  
Bo Yang ◽  
Chun Yan Ju ◽  
Li Hui Zhang
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Laser Cladding ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Dry Friction ◽  
Wear Behavior ◽  
Solidification Rate ◽  
Aluminum Bronze ◽  
Lubricate Condition

In the paper, a Ni-base composite cladding was cladded on the surface of QAl9-4 aluminum bronze by laser cladding technology, as well as its microstructure and tribological properties are studied. The results show that the microstructure of laser cladding is affected by solidification rate, and its wear behavior mainly lies on microstructure and lubrication condition. The microstructure of laser cladding is made up of cellular crystal and dendrite crystal. The microstructure of the surface cladding is cellular crystal, the middle section is crassitude dendrite crystal, and the bottom is coarse dendrite crystal and cellular crystal. Under dry friction condition, wear mechanism is abrasive wear and shedding strengthen phase, which has higher volume’s wear rate. Under lubricate condition, wear mechanism is abrasive wear and adhere wear, which has lower volume’s wear rate than that of dry friction. The average friction coefficient of the cladding under dry and lubricate condition are 0.39 and 0.15, the volume’s wear rate are 7.88×10-8mm3/N.mm and 1.56×10-9mm3/ N.mm, respectively. Therefore, the cladding has favorable wear resistance property under lubricate condition，and can be used as an excellent wearable material.

Laser cladding of Co-based metallic powder at cryogenic conditions

2019 ◽  
Vol 1 (95) ◽  
pp. 20-31
Author(s):  
A. Lisiecki ◽  
D. Ślizak ◽  
A. Kukofka
Keyword(s):  
Liquid Nitrogen ◽  
Laser Cladding ◽  
The Novel ◽  
Novel Technique ◽  
Custom Made ◽  
Nozzle Head ◽  
Forced Cooling ◽  
Liquid Nitrogen Bath ◽  
Cryogenic Conditions ◽  
Conventional Laser

Purpose: of this paper was demonstration a novel technique of laser cladding by experimentally composed Co-based metallic powder and forced cooling of the substrate by liquid nitrogen under cryogenic conditions, at the temperature -190°C, for producing clad layers with enhanced microstructure characteristic and properties. Design/methodology/approach: Technological tests of laser cladding were conducted by means of a high power fibre laser HPFL with maximum output power 3.0 kW, and six-axis robot. The experimental Co-based powder was composed for providing high abrasive wear resistance, high resistance for impact load, and also for corrosion resistance at elevated temperature. The unique and novel technique of forced cooling of the substrate was provided by immersing the specimens in the liquid nitrogen bath. The three coaxial nozzle head was designed and custom made to provide precise deposition of the powder delivered into the laser beam irradiation region. The scope of the study included tests of conventional laser cladding at free cooling in ambient air in a wide range of processing parameters, and also trials of laser cladding under cryogenic conditions. The test clad layers produced by conventional laser cladding and by the novel technique of laser powder deposition under cryogenic conditions were investigated and compared. Findings: The obtained results indicate that the novel technique of forced cooling the substrate by liquid nitrogen bath provides lower penetration depth, as well as low dilution of the clad, and also provides higher hardness of the clads. Additionally, it is possible shaping the geometry of the individual bead, providing high reinforcement and low width. Research limitations/implications: The presented results are based just on preliminary test of the novel technique of laser cladding under cryogenic conditions. Therefore, further study and detailed analyse of the influence of the cooling rate on the quality, microstructure, and properties of the deposited coatings are required. Practical implications: The study is focused on practical application of the novel technique for manufacturing of wear resistance coatings characterised with enhanced performance compared to conventional range of application of the laser cladding. Originality/value: Novel technique of laser cladding at forced cooling under cryogenic conditions was demonstrated. The powder used for cladding trials was experimentally composed (not commercially available). The experimental stand custom made was used with custom made powder feeding rate, and also with custom made coaxial nozzle head.

Experimental study on the effect of surface texture on tribological properties of nanodiamond films under water lubrication

2021 ◽  
pp. 135065012110334
Author(s):  
Ying Yan ◽  
Xuelin Lei ◽  
Yun He
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Surface Texture ◽  
Diamond Film ◽  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Water Contact ◽  
Texture Density ◽  
Short Run

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.

Core-shell structural iron based met al matrix composite powder for laser cladding

2021 ◽  
pp. 160127
Author(s):  
Zhen Wang ◽  
Mixue Tan ◽  
Jiang Wang ◽  
Jing Zeng ◽  
Fengjun Zhao ◽  
...  
Keyword(s):  
Matrix Composite ◽  
Laser Cladding ◽  
Composite Powder ◽  
Core Shell ◽  
Iron Based ◽  
Structural Iron ◽  
Al Matrix Composite ◽  
Al Matrix

Phase transformation and tribological properties of Ag-MoO 3 contained NiCrAlY based composite coatings fabricated by laser cladding

2017 ◽  
Vol 93 ◽  
pp. 79-86 ◽  
Author(s):  
Lingqian Wang ◽  
Jiansong Zhou ◽  
Benbin Xin ◽  
Youjun Yu ◽  
Shufang Ren ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Laser Cladding ◽  
Tribological Properties ◽  
Composite Coatings

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.

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