Adhesive Wear Tests Research Articles

High-Performance Molybdenum Coating by Wire–HVOF Thermal Spray Process

Coating deposition on many industrial components with good microstructural, mechanical properties, and better wear resistance is always a challenge for the thermal spray community. A number of thermal spray methods are used to develop such promising coatings for many industrial applications, viz. arc spray, flame spray, plasma, and HVOF. All these processes have their own limitations to achieve porous free, very dense, high-performance wear-resistant coatings. In this work, an attempt has been made to overcome this limitation. Molybdenum coatings were deposited on low-carbon steel substrates using wire–high-velocity oxy-fuel (W-HVOF; WH) thermal spray system (trade name HIJET 9610®). For a comparison, Mo coatings were also fabricated by arc spray, flame spray, plasma spray, and powder-HVOF processes. As-sprayed coatings were analyzed using x-ray diffraction, scanning electron microscopy for phase, and microstructural analysis, respectively. Coating microhardness, surface roughness, and porosity were also measured. Adhesion strength and wear tests were conducted to determine the mechanical and wear properties of the as-sprayed coatings. Results show that the coatings deposited by W-HVOF have better performance in terms of microstructural, mechanical, and wear resistance properties, in comparison with available thermal spray process (flame spray and plasma spray).

The Wear of Glass Fiber Reinforced Polyester Composite Materials at Different Loads and Speeds

Glass fiber reinforced polyester (GFRP) materials which are polymer matrix composites have some properties such as high specific strength, excellent elasticity, low weight, high corrosion resistance, high chemical resistance and high thermal stability. One of most important causes of failure of mechanical parts is wear. It is a surface property that can be reduced by changing the surface chemistries of the materials and microstructures. For this reason GFRP materials should be investigated not only for their mechanical properties but also for their tribological behaviours. The aim of this study is investigation of effects of different fillers and resins materials on adhesive wear properties of GFRP at different loads and speeds. In the sample production, different resins (reactive orthophtalic polyesters), reinforcing materials and fillers (glass beads, alumina) are used. . Initially, the samples were subjected to adhesive wear tests on two different loads (F=10N, F=20N) and two different speeds (n=100rpm, n=200rpm) at 150m sliding distance. The friction force and friction coefficient were measured during the test on tribometer. The densities of samples were measured. In the next step, the wear trace thicknesses were measured and the wear rates were calculated. In results, the addition of glass beads to plain orthophtalic polyester resin reduced wear rate. The influence of load effect on wear behavior of samples is more the influence of speed.

Effects of coupling agent addition on the adhesive wear, frictional and thermal properties of glass fiber-reinforced polyamide 6,6 composites

In this study, effects of coupling agent addition on adhesive wear, thermal and morphological properties of glass fiber-reinforced polyamide 6,6 (PA6,6) composites were investigated. 1,4-Phenylene-bis-oxazoline (PBO) was used as coupling agent to improve the interfacial adhesion between glass fiber and PA6,6 matrix. While coupling agent loading level was changed as 0.5, 1.0 and 2.0 wt%, glass fiber loading level was fixed at 10 wt% in the composites. For tribological characterization of prepared composites, adhesive wear test was performed. Differential scanning calorimeter analysis and thermogravimetric analysis were performed for thermal characterization. In addition to this, scanning electron microscopy analysis was applied to investigate the worn surfaces and fracture surfaces of samples. Applied test results revealed that 2 wt% PBO addition improved the fiber–matrix adhesion and correspondingly adhesive wear resistance of glass fiber-reinforced PA6,6 matrix composites.

Influence of friction stir processing parameters on the wear resistance of aluminium alloy AA5083

In this study, friction stir processing was applied on AA5083, with an objective to improve its wear resistance. FSP was conducted by varying tool rotation speed, tool traverse speed and tool shoulder diameter as per face centered central composite design. Adhesive wear test was performed using a pin-on-disc tribometer. The test results indicate that the wear resistance of most of the friction stir processed specimens was higher than the base material. A mathematical model was generated for predicting the wear resistance using linear–radial basis function and it was used to explore the influence of process parameters on the wear resistance.

Comparative Study of Adhesive Wear for CoCr, TiC-NiMo, WC-Co as Potential FSW Tool Materials

Friction stir welding is a novel and promising joining process and most common welding tool failure is transformation of geometry caused by wear. In our point of view, this is adhesion wear. The lathe testing of adhesion wear was conducted to compare wear resistance of following materials: Co-25wt%Cr, TiC-25wt%Ni/Mo and WC-6wt%Co. According to characteristics of investigated materials, they are capable to become alternatives for conventional frictional stir welding (FSW) tool materials. Adhesive wear tests were performed by turning aluminium alloy AW6082-T6 at low speed – travel length, turning speed and feed rate were selected to simulate FSW conditions. The adhesive wear was determined as the change of the geometry of the cutting edges of the tool measured using SEM images. Most promising tool material in terms of adhesion wear resistance is WC-Co hardmetal. The two main stages of wear were distinguished: at first, the appearance of intensive adhesion wear followed by steady state wear. Surface fatigue wear complements development of the adhesive wear.

Fused Silika Takviye Edilmiş Al Alaşımı Kompozitlerin Aşınma Davranışı Üzerine Magnezyumun Etkisi

Bu calismada, vakum infiltrasyon yontemi ile uretilen fused silika takviye edilmis Al-10Si kompozitlerin abrasif asinma davranisi uzerine magnezyumun etkisi arastirilmistir. Abrasif asinma testleri, 60, 100, 220 ve 400 numarali Al2O3 zimparalar ile, 10, 20 ve 30 N yukler altinda, 0.1 m/s. kayma hizinda disk uzerinde pim asinma cihazi kullanilarak gerceklestirilmistir. Infiltrasyon yonteminde, matriks malzemesi olarak Al10Si ve Al10Si+%5 Mg alasimlari kullanilmistir. Al10Si alasimina % 5 Mg ilavesinin, 60 Mesh zimpara ve 20-30 N yuk sartlarinda, matriksin asinma kaybinin arttirdigi, ancak kompozitlerinin asinma kaybinin azalttigi tespit edilmistir. Ayrica deneysel asinma sonuclarinin analiz edilmesi icin minitab V16 istatistiksel analiz programi kullanilmistir. Istatistiksel analiz sonuclari, asinma testlerinde en etkin parametrenin asindirici parcacik boyutu oldugunu gostermektedir.

Characterization of Tungsten Carbide coatings deposited on AISI 1020 steel

In order to determine the variation in the mechanical properties of AISI 1020 standardized steel, heat treated by a quenching and tempering process and with a Tungsten Carbide coating, was performed a microstructural and chemical characterization of the coating material through electron microscopy scanning and X-ray energy dispersive spectroscopy. The steel received a heat treatment of quenching performed by heating to 850°C, followed by cooling in water and tempering at a temperature of 450°C with air cooling. Tests of a) microhardness with a Wilson-Wolpert Tukon 2100B micro durometer and b) resistance to adhesive and abrasive wear following the ASTM G99-05 “Standard test method for wear testing with a pin-on-disk machine” and ASTM G65-04 “standard test method for measuring abrasion using dry sand and rubber Wheel” standards respectively. The results show that the microhardness of the steel do not vary with the load used to perform the test; in addition, the heat treatment of quenching and tempering improves by 5.5% the property while the coating increase it by 124.2%. Regarding the abrasive wear resistance, it is observed that the amount of material lost increases linearly with the distance covered. It was determined that the heat treatment decreased on average by 17.5% the volume of released material during the tests while the coating recued it by 66.7%. The amount volume of material lost during the adhesive wear tests increases linearly with the distance covered while the heat treatment decreased on average by 10.5% the volume of released material during the trial and the coating reduced it by 66.5%.

Effect of low temperature annealing on the wear properties of NITINOL

NiTi shape memory alloy is a wonder material that is a solution looking for problems. The material finds wide biomedical applications like endodontic files for root canal treatment and cardiovascular stents. This material has rendered the surgical procedure simple compared to that with the existing Stainless Steel (SS) or titanium ones. NiTi as an endodontic file would cause less discomfort to the patients in comparison to that with far stiffer SS or titanium ones. Here nearly equi-atomic 50:50 commercial NiTi rods were subjected to low temperature aging at 300 to 450°C. The wear resistance of the as-received and the heat-treated samples was studied using adhesive wear tests on hardened steel counter face. Abrasive wear tests were run against Alumina disc to simulate the working of endodontic drills and files against dental hard and soft tissues. The abrasive wear resistance is expected to be proportional to the Vickers Hardness of the material and is high for the 450°C heat-treated sample. A correlation between the mechanical properties and microstructures of this material is attempted

Investigating the effect of testing parameters on adhesive wear using Taguchi method

The aim of this study is to investigate the effect of working parameters on wear resistance of steels in terms of applied load, hardness and revolution per minute (rpm) using the Taguchi method. Pin-on-roller type of apparatus was used for adhesive wear tests. The operating parameters were investigated by employing the orthogonal array, signal-to-noise ratio and analysis of variance. The experimental wear test results show that the hardness of the materials is the major parameter among the controllable factors. After the hardness, the applied load and the rpm sequentially have influence on the wear resistance of three types of steels; AISI 1050, AISI 4140 and AISI 8620. The best wear testing parameters were determined for current conditions of the steels. A good agreement between the predicted and experimental wear amounts is observed.

Comparative of wear resistance of low carbon steel pack carburizing using different media

In this study, various carburizing compounds charcoal, cow bone, CaCO3 were added as energizer for the carburizing compounds in percentage of 10%. To produce another compound to pack carburized mild steel 1020 AISI for investigates the influence of these compounds on wear resistance.Many Cylindrical specimens for the adhesion wear tests were prepared from the used metal with dimensions (10x20mm) according to ASTM (G99-04) specificationsThree Heat Treatment process namely pack Carburizing Quenching, and Tempering were done. Firstly the mild steels specimens are carburized at 925° C for 2hr as soaking time and slow cooling in furnace then carburizing specimens were re heating to 870 °C for half hr. and water Quenching .Tempering was done at 160°C for 1 hour and air cooled. the Carburized and Tempered mild steels are subjected for different kind of test such as Adhesive Wear Test with pin on desk method, Hardness Test were taken using Vickers micro-hardness tester and optical microscope is used for microstructure examination X-ray diffraction for phases observation.The result showed that all carburizing compound were contributed in increasing wear resistance and the compound of cow bone with 10% CaCO3 as energizer had a carburizing case depth of 2.32 mm which gives the highest wear resistance while charcoal compound gives a case depth of 1.1 mm .The work shows that cow bone can be used as compounds and energizer in pack carburization of mild steel. The hardness profile plot of the 90 wt.% 10% caco3 cow bone carburized mild steel was also higher than the other compositions and this value contributed on improvements of wear resistance.

Performance Thermally Sprayed Coatings Tests when Subject to Adhesive Wear

In this study it was evaluated the performance of coatings based on Cr3C2-25 (80Ni-20Cr) and CrC-30NiCr. The coatings were deposited by high velocity oxygen fuel (HVOF), with an average thickness of layer equal to 7.8μm. Samples were subjected to adhesive wear test (according ASTM G99) with a pin Ø 6 mm (SAE 52100). In the test was applied normal force equal to 50 N and tangential speed equal to 0.5 m/s. The test time was 30 minutes at room temperature, without lubrification. The wear surfaces were characterized by optical microscopy, scanning electron microscopy and X-ray diffraction. The microhardness of the coatings was also evaluated. The results showed that the coating based on Cr3C2-25(80Ni-20Cr) presented a performance ten times higher in wear resistance when compared to coating CrC-30NiCr.

Investigation of a hydrothermal reduced graphene oxide nano coating on Ti substrate and its nano-tribological behavior

In this study, a deposited Ti substrate was orderly assembled with 3-aminopropyltriethoxysilane (APTES) and graphene oxide (GO) sheets by way of self-assembly. The top layer GO sheets were reduced via hydrothermal route. Chemical characterizations, including XPS, FTIR and UV–vis analysis, together with AFM morphology investigations were implemented and results proved that the obtained coating was successfully prepared on Ti substrate, with a highly deoxidation effectiveness for GO sheets. Nano-tribological investigations including adhesion force, friction force and wear tests indicated that the coating behaves as an effective anti-friction and anti-wear coating for the substrate.

Compressive, tensile and wear behavior of ex situ Al/AlN metal matrix nanocomposites

The mechanical strength and wear behavior of Al–AlN metal matrix nanocomposites synthesized using melt metallurgy technique is investigated. Uniformly dispersed nanostructured AlN particulates in nanocomposites are found to improve the mechanical properties. Detailed study on compressive and tensile test is attempted in the present work to understand the mechanism of deformation in nanocomposites. Adhesive dry wear test results indicate that applied load has strong influence on wear behavior of nanocomposites compared to the sliding distance. Porosity and weak agglomeration of nanoparticles are found to significantly affect the wear behavior and mechanical strength of synthesized nanocomposites. It is revealed that the transfer of load from matrix to reinforcement particulate is not an instantaneous phenomenon but initiates after some incubation period depending on the fraction of porosity in nanocomposites during compressive and tensile testing.

The Effect of Low Temperature Plasma Nitriding on Wear Resistance of Ti6Al4V Alloy

The e ect of low temperature plasma nitriding on wear resistance of Ti6Al4V alloy were investigated. There have been several studies to investigate the low temperature plasma nitriding on Ti6Al4V alloy. Plasma nitriding processes under gas mixture of N2/H2 = 3 were performed at temperature 535 ◦C for duration of 4, 8 and 12 h. Adhesive wear tests were carried out by using a tribometer in block-on-ring con guration (ASTM G77), in sliding conditions, without lubricants and in air. Surface hardness of the plasma nitrided samples were measured by a Vickers hardness tester machine. Scanning electron microscopy studies were conducted to understand the wear mechanisms involved during the adhesive wear. Wear rate was calculated using weight loss per unit sliding distance. It was found that the wear resistance and surface hardness of the alloy improved considerably after plasma nitriding process. The wear resistance of the plasma nitrided samples were higher than of the unnitrided samples. Extension of nitriding times from 4 h to 12 h in the Ti6Al4V alloy improved remerkably the wear resistance and surface hardness.

NiTi superelastic orthodontic archwires with polyamide coating

Twenty orthodontic archwires with 55.2% Ni and 44.8% Ti (% weight) were subjected to a dipping treatment to coat the NiTi surface by a polyamide polymer. It has been selected a Polyamide 11 due to its remarkable long lasting performance. The transformation temperatures as well as the transformation stresses of the NiTi alloy were determined in order to know whether the coating process can alter its properties. The adhesive wear tests have been demonstrated that the wear rates as well as the dynamic friction coefficients μ of polymer coated wires are much lower than metallic wires. The corrosion studies have shown that the use of this polymer, as coating, seals the NiTi surface to prevent corrosion and the release of nickel ions. The average decrease of Ni ions release due to this coating is around 85%.

EFFECT OF SIZE REFINEMENT AND DISTRIBUTION OF THE LUBRICATING LEAD PHASES IN THE SPRAY FORMING HIGH-LEADED TIN BRONZE ON WEAR RATES

Recently, the wear properties of high-leaded tin bronze were greatly concerned. In this work, the effect of size refinement and distribution of the lubricating lead phases in the spray forming (SF) high-leaded tin bronze on wear rates was studied by using scanning electron microscopy and sliding adhesive wear tests. It was observed that compared to the conventional casting bronze, the SF bronze features finer and more dispersed lead phases that formed more lubricating films in microstructure, which leads to the less wear rates.

Effect of SiC Addition the on Adhesive Wear Resistance of 6061 T6 Aluminum Alloy

This paper is aimed to study the effect of SiC addition as reinforcement to 6061 T6 alloy. Al 6061 T6 alloy SiC composites were prepared by melting the alloy in a vortex and adding 4 % and 10% weight fractions of SiC. Then pouring the mixture into a mould to obtain a bar of 12 mm diameter and 150 mm length. Wear specimens were manufactured in dimensions of 20mm x 10mm according to ASTM to the base alloy and the cast matrix alloy. Microstructure have been carried out to understand the nature of structure and Hardness test also implemented to specimens. Adhesive wear test have been conduct both on the alloy and composites at different parameters (time, load and velocity). From the obtained results, it was found that wear resistance improved during the carbide addition comparing with the base alloy as a result of SiC addition which contributed in improving the hardness of the alloy that reflects to the wear resistance and these properties were improved as the increasing of the carbide silicon percentage.

Performance evaluation of chitosan/hydroxyapatite composite coating on ultrahigh molecular weight polyethylene

The aim of the present study is to evaluate the performance of chitosan/hydroxyapatite (CTS/HA) coatings on ultrahigh molecular weight polyethylene (UHMWPE). We focused on adhesion measurements, micro-hardness indentation, friction and wear tests. Using commercial compounds of medical grade, CTS/HA composite was prepared by a simple mixture using acetic acid as solvent. The CTS/HA solution obtained was used to prepare coatings on UHMWPE substrates by the immersion method. Scanning electronic microscopy (SEM) results showed that the composite coating had flake-like morphology characteristic of chitosan and calcium phosphate powders with a porous structure. The adhesion strength between CTS-HA coating and UHMWPE was approximately 0.15 MPa, according the ASTM D5179 method. The micro-hardness of CTS/HA coating on UHMWPE was evaluated by using a Vickers hardness tester, while friction and wear were studied by a pin-on-disk method in dry conditions.

Evaluation of Changes in Microstructural Coatings Deposited by Thermal Spray

In this work, microstructural changes in coatings deposited by hypersonic thermal spraying technique (HVOF) were subjected to adhesive wear tests. Materials subjected to wear lose efficiency, increase costs and direct or indirect way can stop large production systems. The mechanisms involved in this type of wear can be minimized by the microstructural changes that in many cases reduces or stops the loss of material. To perform this assessment coatings compounds of Cr3C225 (80 Ni-20 Cr) e Al2O3.TiO2 (87-13) investigated had similar hardness values (1000 HV) and chemical characteristics. Were subjected to the ASTM G99 using commercial hard metal pin 2 mm, load 50N force and tangential velocity of 0.5 m/s. Worn surfaces and debris were analyzed by optical microscopy, scanning electron microscope and mass loss. The results show high resistance sprayed coatings worn surfaces and debris were fragile nature with little loss of material during the tests.

EFFECTS OF α-Al2O3 NANOADDITIVE ON THE PROPERTIES OF CERAMIC COATINGS PREPARED IN BORATE ELECTROLYTE BY MICRO-ARC OXIDATION

Ceramic coatings have been synthesized on 6063 aluminum alloy by micro-arc oxidation (MAO) technique in the solution of Na2B4O7 electrolyte with and without α- Al2O3 nanoadditive. Effects of α- Al2O3 nanoadditive on the phase composition, micro-structure, micro-hardness, adhesion and wear resistance of the prepared ceramic coatings have been investigated in this paper. The phase composition and microstructure of the MAO coatings were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDX) analyses, respectively. Micro-hardness, adhesion and tribological and wear tests were also performed. The results showed that the α- Al2O3 nanoadditive doped in the electrolyte had great influence on the structural and mechanical properties of the ceramic coatings.