scholarly journals The Impact of Heat Treatment on the Behavior of a Hot-Dip Zinc Coating Applied to Steel During Dry Friction

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 660
Author(s):  
Dariusz Jędrzejczyk ◽  
Elżbieta Szatkowska

The analyzed topic refers to the wear resistance and friction coefficient changes resulting from heat treatment (HT) of a hot-dip zinc coating deposited on steel. The aim of research was to evaluate the coating behavior during dry friction after HT as a result of microstructure changes and increase the coating hardness. The HT parameters should be determined by taking into consideration, on the one hand, coating wear resistance and, on the other hand, its anticorrosion properties. A hot-dip zinc coating was deposited in industrial conditions (according EN ISO 10684) on disc-shaped samples and the chosen bolts. The achieved results were assessed on the basis of tribological tests (T11 pin-on-disc tester, Schatz®Analyse device, Sindelfingen, Germany), microscopic observations (with the use of optical and scanning microscopy), EDS (point and linear) analysis, and microhardness measurements. It is proved that properly applied HT of a hot-dip zinc coating results in changes in the coating’s microstructure, hardness, friction coefficient, and wear resistance.

2013 ◽  
Vol 853 ◽  
pp. 264-269 ◽  
Author(s):  
Gökce Dil ◽  
Ali Göksenli ◽  
Cagdas Calli ◽  
Faiz Muhaffel ◽  
Ali I. Aydeniz ◽  
...  

The present work deals with the formation of NiP/NiB duplex coatings by electroless plating and evaluation of their hardness and wear resistance. The duplex coatings were prepared with Ni-P as the inner layer. To analyze the structure of the coatings, XRD analysis was carried out. According to the results, NiP and NiB coatings are amorphous in their as-plated condition and after applying heat-treatment at 450 °C for 1 h, both NiP and NiB coatings crystallize and produce nickel, nickel phosphide and nickel borides in the coatings. To determine the surface morphology and cross-section characteristics of the coatings, SEM observations were carried out and concluded that duplex coatings are uniform and good coherent exists between the duplex layers and the coatings are also connected closely to the substrate. The hardness of electroless nickel duplex coatings increased with applying heat treatment and reached maximum value at coatings annealed at 400 °C. To analyze the tribological properties, pin-on-disc tests were carried out. The wear track patterns on the coatings and on Al2O3balls were then examined by optical microscopy and EDS. The friction coefficient and wear rate of the coatings were lower than the substrate steel. Friction coefficient decreased from 0.43 to 0.36 and wear resistance decreased from 11.3 to 6.4 by applying heat treatment at 450 °C for 1 h to duplex coatings.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1655
Author(s):  
Dariusz Jędrzejczyk ◽  
Wojciech Skotnicki

The presented studies are focused on the wear resistance and friction coefficient changes of the thermal diffusion (TD) zinc coating deposited on steel. The aim of research was to evaluate the variation in coating properties during dry friction as a result of the method of preparation of the basis metal. The measured properties were compared to those obtained after classic hot-dip (HD) zinc galvanizing—heat treated and untreated. Thermal diffusion zinc coatings were deposited in industrial conditions (according to EN ISO 17668:2016-04) on disc-shaped samples. The results obtained during the tribological tests (T11 pin-on-disc tester) were analysed on the basis of microscopic observations (with the use of optical and scanning microscopy), EDS (point and linear) analysis and microhardness measurements. The obtained results were similar to effects observed after heat treatment of HD zinc coating. The conducted analysis proved that the method of initial steel surface preparation results in changes in the coating’s hardness, friction coefficient and wear resistance.


Author(s):  
Fathima Banu Raza ◽  
Anand Kumar

The o-rings in ball retained overdentures deteriorate with time and need replacement to restore the retentive quality. We evaluated retrospectively the mechanical properties of o-rings after 3 years in function in one and two-piece implant-supported overdentures. The o-rings were retrieved from one-piece (Myriad snap, Equinox-Straumann, 3.3 x 13mm) and two-piece (Neo Biotech, 3.3 x 13mm) implant-supported overdenture patients. A total of 16 pairs of matrices were tested for wear, type of damage and elasticity using Pin on Disc method, USB Digital Camera in 30x zoom and Universal Tensile Machine respectively. The statistical analysis for independent groups were done with the Mann-Whitney U test. Assessment of used O-rings showed 84% more wear in the two-piece system with an abrasive type of damage while 46% wear in the one-piece system with a compressive type of damage. The o-rings in one-piece system showed increase in elongation and maximum displacement to 2% and 7% respectively, while two-piece system showed decrease in elongation and maximum displacement by 13% and 6% respectively. In one-piece system, the loss of retention was more with slow wear rate and in two-piece system, the wear resistance of O-rings decreased due to increased stiffness. Further studies to evaluate the changes in O-ring with increased sample size and at interval 1 year will pave way for insight into the progressive changes in the mechanical properties of an O-ring.


Vestnik MGSU ◽  
2019 ◽  
pp. 311-321
Author(s):  
Elena M. Gotlib ◽  
Аlmira R. Khasanova ◽  
Engel R. Galimov ◽  
Аlla G. Sokolova

Introduction. Domestic mineral natural-origin filler ‘wollastonite’, also known as calcium methyl silicate, is widely used as a base for wear-resisting epoxy antifriction materials. Due to anisodiametric shape of its particles, wollastonite functions as a micro reinforcement fibre enhancing adhesion strength and wear resistance of epoxy compositions, improving their antifriction properties, especially when organomodifying by quaternary ammonium salts. In this regard, the investigation of the impact of chemical composition of such surfactants as quaternary ammonium salts on the properties of epoxy compound materials presents utmost interest for researchers developing low-friction materials. Materials and methods. Epoxy diane resin ED-20 was hardened with aminoalkylphenol AF-2. Content of epoxy hardener was determined by equimolar ratio of epoxy groups to amine groups. Domestic wollastonite of the grade Miwoll 10-97 was used as filler, particle length to the diameter correlated as 15:1. The wollastonite surface was activated with surfactants belonging to domestically produced quaternary ammonium salts. Wear resistance of specimens was tested by means of the vertical optical caliper IZV-1. Friction coefficient was estimated with the assistance of the computer-automated frictional machine CSM Instruments Tribometer. Adhesion strength of glue joint was determined as per GOST 28840-90 standard. Two bars of sheet aluminium were used as glued surfaces as per GOST 14759-69 standard. Results. Reduction of wear of epoxy coatings when modified with micro reinforcing wollastonite can be explained by the increase of cross-linking degree of the polymer. The length of alkyl radical of quaternary ammonium salts used for wollastonite surface activation affects the intervals between the epoxy links. As the quaternary ammonium salt chain length is growing, wear of epoxy materials is reducing. Introduction of the wollastonite containing metallic oxides in the epoxy composites increases wear resistance and adhesion strength and reduces coating friction coefficients. Conclusions. Hardened with the AF-2 and filled with the wollastonite of the Miwoll 10-97 grade, the epoxy compound materials have enhanced wear resistance and adhesion strength and lower friction coefficient. The best result is observed when applying wollastonite modified with a surfactant belonging to the class of quaternary ammonium salts. The wollastonite can be used for practical purposes as a perspective reinforcing agent for epoxy materials with improved wear resistance, enhanced adhesion to metals and reduced friction coefficient.


2019 ◽  
Vol 71 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Yanzhen Wang ◽  
Zhongwei Yin

PurposeThis purpose of this study was to investigate the effects of carbon fiber (CF) and/or glass fiber (GF) fillers on the tribological behaviors of ultrahigh-molecular-weight polyethylene (UHMWPE) composites to develop a high-performance water-lubricated journal bearing material.Design/methodology/approachTribological tests were conducted using a pin-on-disc tribometer using polished GCr15 steel pins against the UHMWPE composite discs under dry conditions with a contact pressure of 15 MPa and a sliding speed of 0.15 m/s. Scanning electron microscopy, laser 3D micro-imaging profile measurements and energy-dispersive X-ray spectrometry were used to analyze the morphologies and elemental distributions of the worn surfaces.FindingsThe results showed that hybrid CF and GF fillers effectively improved the wear resistance of the composites. The fiber fillers decreased the contact area, promoted transfer from the polymers and decreased the interlocking and plowing of material pairs, which contributed to the reduction of both the friction coefficient and the wear rate.Originality/valueThe UHMWPE composite containing 12.5 Wt.% CF and 12.5 Wt.% GF showed the best wear resistance of 2.61 × 10−5mm3/(N·m) and the lower friction coefficient of 0.12 under heavy loading. In addition, the fillers changed the worn surface morphology and the wear mechanism of the composites.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 635 ◽  
Author(s):  
Fang Han ◽  
Huaixing Wen ◽  
Jianjian Sun ◽  
Wei Wang ◽  
Yalong Fan ◽  
...  

This paper concerns a comparative study on the tribological properties of Si3N4-10 vol% hBN bearing on GCr15 steel under seawater lubrication and dry friction and fresh-water lubrication by using a pin-on-disc tribometer. The results showed that the lower friction coefficient (around 0.03) and wear rate (10−6 mm/Nm) of SN10/GCr15 tribopair were obtained under seawater condition. This might be caused by the comprehensive effects of hydrodynamics and boundary lubrication of surface films formed after the tribo-chemical reaction. Despite SN10/GCr15 tribopair having 0.07 friction coefficient in the pure-water environment, the wear mechanismsits were dominated by the adhesive wear and abrasive wear under the dry friction conditions, and delamination, plowing, and plastic deformation occured on the worn surface. The X-ray photoelectron spectroscopy analysis indicated that the products formed after tribo-chemaical reaction were Fe2O3, SiO2, and B2O3 and small amounts of salts from the seawater, and it was these deposits on the worn surface under seawater lubrication conditions that, served to lubricate and protect the wear surface.


2019 ◽  
Vol 130 ◽  
pp. 01023
Author(s):  
Pritamara Wahyuningtyas ◽  
Anne Zulfia Syahrial ◽  
Wahyuaji Narottama Putra ◽  
Budi Wahyu Utomo

A study of ADC12 (Al-Si aluminium alloy) composite is conducted to obtain a more sustainable material with enhanced properties for automotive industry purpose, such as train's brake shoe and bearing application. For those kind of utilization, material with durability, good elastic modulus, thermal stability, wear resistance, and high strength properties is needed due to its exposure to high temperature and heavy continuous application. ADC 12 acts as the matrix, reinforced with 3 vf% micro-SiC with 5 wt% Mg wetting agent was fabricated by the stir casting method. The addition of 0.18 wt% Sr and 0.15 wt% TiB were expected to finer the grain morphology of the silicone eutectic phase and to acts as the grain refiner, respectively. Furthermore, T6 heat treatment was applied with aging temperature 150 °C, 170 °C, 190 °C, 210 °C, and 230 °C, following the prior 1 h 490 °C solution treatment. The results obtained in this work showed enhancement in tensile strength with the value of 213 MPa, hardness value 75 HRB, and wear resistance. These values increase up to 115 MPa for the UTS and 38 HRB for the hardness value, as the impact of the refined grains from both modifiers and heat treatment.


2012 ◽  
Vol 602-604 ◽  
pp. 456-459
Author(s):  
Jing Lai Tian ◽  
Fang Xia Ye ◽  
Li Sheng Zhong ◽  
Yun Hua Xu

In-situ production of (Fe,Cr)7C3 particulate bundles -reinforced iron matrix composite was prepared by infiltration casting between Cr wires and white cast iron at 1200°C plus subsequent heat treatment. The composites under different heat treatment times were comparatively characterized by scanning electron microscopy (SEM) and pin-on-disc wear resistance tests. The results show that the area of the particle bundles gradually increases with the heat treatment time increasing, and the chemical compositions change from eutectic to hypoeutectic, the morphologies of the reinforcements present chrysanthemum-shaped, granular and intercrystalline eutectics. Under 5 N loads, the composites appear excellent wear resistance, which is 36 times for the reference sample.


Tribologia ◽  
2016 ◽  
Vol 269 (5) ◽  
pp. 183-193
Author(s):  
Wojciech TARASIUK ◽  
Mariusz LISZEWSKI ◽  
Bazyli KRUPICZ ◽  
Ewa KASPRZYCKA

This paper presents the results of tribological tests performed on a T-11 pin-on-disc type, which made it possible to determine the intensity of abrasive wear of steel 20MnCr5 subjected to selected thermo-chemical heat treatments. The tested steel, after the hardening and tempering process, is characterized by high endurance parameters and is used on heavily loaded machine parts. It is frequently used for elements subjected to intense abrasion. The analysis involved the following: carburizing, boronizing, and various methods of diffusion chromizing. For large loads, it is advisable to apply boronizing or carburizing with hardening. Chrome plating entails a very thin layer of increased hardness, which is characterised by a low abrasive wear resistance at high loads.


2016 ◽  
Vol 724 ◽  
pp. 20-27 ◽  
Author(s):  
A. Saad Najim ◽  
A. Kadhum Ola

In present work, the influences of TiO2 nanoparticles addition on the tribological and mechanical behavior of polyphenylene sulfide (PPS) were investigated. The composites samples containing TiO2 nanoparticles at various percentages (0, 1, 3, and 6 wt. %) were prepared by melt mixing process using single screw extruder at 325 °C and 20 rpm. A pin-on-disc sliding test machine was used for measurement of wear volume and the friction coefficient. The counterface was made of steel carbide with roughness 0.1 μm Ra. The tests were run at a sliding speed of 0.4 m/s and 1 m/s, the contact pressure 0.65 Mpa with different sliding distances (5, 10, 15 and 20 km). Mechanical properties of PPS nanocomposites were studied to evaluate the influence of the nanoparticles addition, as well as examined the relation between the tribological and mechanical behavior. It was found that nanoparticles could further enhance the tribological properties. The lowest wear volume and friction coefficient was observed at 1 m/s was PPS+1wt. %, and for 0.4 m/s was observed in PPS+6wt. %. The results indicate that the mechanical of PPS nanocomposites have been improved, the impact strength and hardness increased with the incorporation of TiO2 nanoparticles. The density was also increased with TiO2 nanoparticles.


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