scholarly journals Effects of Alkyl-Substituted Polybenzoxazines on Tribological Properties of Non-Asbestos Composite Friction Materials

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 567
Author(s):  
Anun Wongpayakyotin ◽  
Chanchira Jubsilp ◽  
Sunan Tiptipakorn ◽  
Phattarin Mora ◽  
Christopher W. Bielawski ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Coefficient Of Friction ◽  
Aromatic Amines ◽  
Underlying Structure ◽  
Methyl Groups ◽  
Friction Materials ◽  
Wear Rates ◽  
Structure Properties ◽  
Crosslink Densities

A series of substituted polybenzoxazines was synthesized and studied as binders in non-asbestos friction composite materials. The structures of the polybenzoxazines were varied in a systemic fashion by increasing the number and position of pendant alkyl (methyl) groups and was accomplished using the respective aromatic amines during the polymer synthesis step. By investigating the key thermomechanical and tribological characteristics displayed by the composite materials, the underlying structure-properties relationships were deconvoluted. Composite friction materials with higher thermomechanical and wear resistance properties were obtained from polybenzoxazines with relatively high crosslink densities. In contrast, polybenzoxazines with relatively low crosslink densities afforded composite friction materials with an improved coefficient of friction values and specific wear rates.

Investigation of three-body wear of dental materials under different chewing cycles

2018 ◽  
Vol 25 (4) ◽  
pp. 781-787 ◽  
Author(s):  
Efe Cetin Yılmaz ◽  
Recep Sadeler
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Dental Materials ◽  
Three Dimensional ◽  
Composite Resins ◽  
Dental Composite ◽  
Volume Loss ◽  
Wear Rates ◽  
Electron Microscopy Analysis ◽  
Three Body

Abstract This paper investigates the three-body wear resistance rates of five restorative dental composite materials at different mastication cycles and compares the results with that of an amalgam material. Five specimens of each material were exposed three-body wear tests using a computer-controlled chewing simulator with steatite balls as the antagonist (1.6 Hz, 49 N load; 120,000, 240,000 and 480,000 mechanical cycles; and thermal cycling between 5 and 55°C at 5 min/cycle and 3000 cycles) immersed in a poppy seed slurry (three-body wear environment). Initially, the microhardness values of the composite materials in the Vicker’s hardness (HV) scale were determined. The mean volume loss of the worn surfaces was measured with a three-dimensional profilometer. Means and standard deviations were calculated, and statistical analysis was performed using one-way ANOVA (α=0.05). Additionally, scanning electron microscopy analysis was performed to examine the wear tracks on the surface. The interactions between the composite resin and mean volume loss were found to be significant. The three-body wear rates for the composites Durafil and Kalore composite were significantly higher than those of the other composites and the amalgam irrespective of the number of mastication cycles. Filtek Z250 and Filtek Supreme composite resins had good three-body wear resistance similar to that of the amalgam. However, this study suggests that the correlation between Vicker’s hardness and three-body wear resistance is not significant.

Dry Sliding Wear of Lu2O3 Sialon Ceramics

2006 ◽  
Vol 317-318 ◽  
pp. 351-354
Author(s):  
Mark I. Jones ◽  
Kiyoshi Hirao ◽  
Hideki Hyuga ◽  
Yukihiko Yamauchi
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Wear Mechanism ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Wear Properties ◽  
Experimental Conditions ◽  
Wear Rates ◽  
Order Of Magnitude

The effects of microstructure and composition on the wear properties of Lu sialon ceramics have been studied under dry sliding conditions through block-on-ring wear tests. Microstructural and compositional effects on wear behaviour were studied by producing both equiaxed and elongated α sialons through the incorporation of additional oxides to promote extended liquid formation and grain growth, and by producing α / β composite materials with elongated β grains. The wear response of the materials is discussed in terms of the dominant wear mechanism under different experimental conditions. Under higher loads, where fracture dominates, materials with improved mechanical properties show better wear resistance and both the composite materials and the elongated α sialons showed lower wear rates than the equiaxed materials due to the elongated grain microstructures. Under low normal loads, fracture does not occur and the dominant wear mechanism is thought to be tribochemically assisted wear. Under these conditions, the equiaxed materials had better wear resistance than the composites, and the Lu-α sialon showed an order of magnitude lower wear rate than an equivalent Y-α sialon, thought to be due to better oxidation resistance and improved refractory nature afforded through the use of the smaller radius cation. The elongated Lu-α sialons under these low load conditions showed wear resistance that was to some extent dependent on the composition of the additional liquid phase, with high SiO2 contents leading to higher wear rates.

TOUGHMET 2CX

Alloy Digest ◽  
2013 ◽  
Vol 62 (6) ◽  
Keyword(s):  
Tensile Strength ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Coefficient Of Friction ◽  
Loading Conditions ◽  
Severe Loading

Abstract ToughMet 2 CX is a Cu-9Ni-6Sn alloy that combines low coefficient of friction with wear resistance. ToughMet alloys are a line of spinodal hardened Cu-Ni antigalling alloys for bearings capable of performing with a variety of shafting materials and lubricants. The alloys combine a high lubricity with wear resistance in these severe loading conditions. ToughMet 2CX in the cast and spinodally hardened (CX) condition exhibits tensile strength in excess of 724 MPa (105 ksi) and hardness exceeding HRC 27 with excellent machinability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Cu-819. Producer or source: Materion Brush Performance Alloys.

scholarly journals Properties of Journal Bearing Materials That Determine Their Wear Resistance on the Example of Aluminum-Based Alloys

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 535
Author(s):  
Alexander Mironov ◽  
Iosif Gershman ◽  
Eugeniy Gershman ◽  
Pavel Podrabinnik ◽  
Ekaterina Kuznetsova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Journal Bearing ◽  
Tribological Behavior ◽  
Secondary Structures ◽  
Magnesium Content ◽  
Wear Rates ◽  
Relative Extension ◽  
Bearing Materials ◽  
Antifriction Alloys

Potential relations of tribological characteristics of aluminum antifriction alloys with their compositions and mechanical properties were investigated. In this regard, the properties of eight aluminum alloys containing tin from 5.4% to 11% doped with lead, copper, silicon, zinc, magnesium, and titanium were studied. Mechanical properties such as hardness, strength, relative extension, and impact strength were analyzed. Within the tribological tests seizure load and wear of material were evaluated and secondary structures were studied afterwards. The absence of a definitive correlation between tribological behavior and mechanical properties was shown. It was determined that doping tin over 6% is excessive. The seizure load of the alloys increases with the magnesium content. Secondary structures of the alloys with higher wear rates contain one order less magnesium and tin.

scholarly journals The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Complex Geometry ◽  
Corrosion And Wear ◽  
Functional Layer ◽  
Scaling Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Duplex Coating ◽  
Wear Protection

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.

Wear Assessment in a Biodiesel Fueled Compression Ignition Engine

2003 ◽  
Vol 125 (3) ◽  
pp. 820-826 ◽  
Author(s):  
A. K. Agarwal ◽  
J. Bijwe ◽  
L. M. Das
Keyword(s):  
Coefficient Of Friction ◽  
Linseed Oil ◽  
Diesel Oil ◽  
Lubricating Oil ◽  
Engine Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Metal Debris ◽  
Wear Rates ◽  
Biodiesel Blend

Biodiesel is prepared using linseed oil and methanol by the process of transesterification. Use of linseed oil methyl ester (LOME) in a compression ignition engine was found to develop a highly compatible engine-fuel system with low emission characteristics. Two similar engines were operated using optimum biodiesel blend and mineral diesel oil, respectively. These were subjected to long-term endurance tests. Lubricating oil samples drawn from both engines after a fixed interval were subjected to elemental analysis. Quantification of various metal debris concentrations was done by atomic absorption spectroscopy (AAS). Wear metals were found to be about 30% lower for a biodiesel-operated engine system. Lubricating oil samples were also subjected to ferrography indicating lower wear debris concentrations for a biodiesel-operated engine. The additional lubricating property of LOME present in the fuel resulted in lower wear and improved life of moving components in a biodiesel-fuelled engine. However, this needed experimental verification and quantification. A series of experiments were thus conducted to compare the lubricity of various concentrations of LOME in biodiesel blends. Long duration tests were conducted using reciprocating motion in an SRV optimol wear tester to evaluate the coefficient of friction, specific wear rates, etc. The extent of damage, coefficient of friction, and specific wear rates decreased with increase in the percentage of LOME in the biodiesel blend. Scanning electron microscopy was conducted on the surfaces exposed to wear. The disk and pin using 20% biodiesel blend as the lubricating oil showed lesser damage compared to the one subjected to diesel oil as the lubricating fluid, confirming additional lubricity of biodiesel.

Paper 16: Friction in Wet Clutches

1967 ◽  
Vol 182 (14) ◽  
pp. 132-138 ◽  
Author(s):  
E. M. Evans ◽  
J. Whittle
Keyword(s):  
Coefficient Of Friction ◽  
Power Transmission ◽  
Sliding Speed ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Sliding Surfaces ◽  
Base Oils ◽  
Wet Friction ◽  
Friction Clutch ◽  
The Coefficient Of Friction

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants. A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.

Enhancement of tribological properties and characteristic of polymer matrix composite (UHMWPE reinforced with short fibres of polyester) for Total Disc Replacement (TDR)

2020 ◽  
Vol 2 (102) ◽  
pp. 55-65
Author(s):  
M.N. Obaid ◽  
S.H. Radhi
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Wear Resistance ◽  
Composite Material ◽  
Thermal Properties ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Total Disc Replacement ◽  
Short Fibres ◽  
The Matrix

Purpose: The number of people suffering from Degenerative Disc Disease (DDD) is increasing. The disease causes heavy pain and restrict a number of day-to-day life activities. In extreme cases, the degraded disc is removed under total disc replacement which is usually made up of Ultra-High Molecular Weight Polyethylene (UHMWPE). The material has astounding biocompatible characteristics mechanical properties and wear resistance. However, these characteristics are insufficient in arthroplasty application. Therefore, research investigations are ongoing to improve tribological properties through reinforcement that may result in a composite material of UHMWPE. Thus the current study is aimed at reinforcing UHMWPE with short fibres of polyesters to enhance the tribological properties and surface characteristic so as to improve wear resistance and nourish the fibroblast cells on synthetic disc. Design/methodology/approach: The researcher prepared UHMWPE composite material, reinforced with different weight fractions of short polyester fibres (2, 4, 6, 8 and 10% following hot press method. Further pin-on-disc device was used to study the tribological properties (coefficient of friction and volume of wear). The study tested surface roughness and surface characteristics by atomic force microscopy (AFM) device, hardness by shore D device, contact angle to study the effect of polyester short fibres on wettability of UHMWPE surface and tested the thermal properties and crystalline degree using Differential Scanning Calorimetry measurement (DSC) device. Findings: The results infer that the wear resistance got improved when using 2% w.t polyester though it got decreased initially. However, the value was still more than neat UHMWPE. There was a decrease observed in coefficient of friction, but after 4 w.t% polyester, the coefficient of friction got increased due to increasing percentage of fibres which make it harder and stiff compared to UHMWPE. There was a decline observed in surface roughness due to alignment of the fibres with smooth surface. The contact angle got increased in a moderate range while the roughness enhanced the growth of fibroblast cell. The hardness of composite material got increased, because the fibres turned stiffer and harder than the matrix. DSC results infer the improvements in thermal stability due to high thermal properties of polyester fibres compared to UHMWPE. The degree of crystallinity got increased which in turn enhanced wear resistance, especially at 6 w.t % polyester fibres. There was a mild increase observed in density since the density of polyester is higher than polymer. Research limitations/implications: The major challenge was the dispersion of fibres. Uniform distribution of fibres within the matrix (UHMWPE) was achieved through two steps of mixing processes such as mechanical mixture and twin extruder. In future studies, fatigue tests must be conducted to study the behaviour of prepared composite materials under fatigue cycle. Practical implications: A significant objective is how to connect among different properties to obtain good improvement in tribological and surface properties so as to enhance wear resistance and growth of fibrolase cells. Originality/value: In this study, polymeric short fibres were used as reinforcement with polymeric matrix to enhance the wettability of fibres with matrix. In this way, the bonding among them got increased which supports the tribological, surface, and crystalline behaviour.

A DEVICE AND TOOL FOR MAKING SAMPLE FROM POLYMER COMPOSITE MATERIALS ON A CNC MACHINE (review)

2021 ◽  
pp. 100-109
Author(s):  
M.I. Minibaev ◽  
◽  
M.N. Usacheva ◽  
V.S. Dyshenko ◽  
V.A. Goncharov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Sheet Metal ◽  
Polymer Composite ◽  
Carbon Fiber Reinforced Plastic ◽  
Cnc Machine ◽  
Fiber Reinforced Plastic ◽  
Advantages And Disadvantages ◽  
Reinforced Plastic

The article discusses devices for fixing sheet metal blanks from PCM: a perforated vacuum table, its design features, advantages and disadvantages. Based on these data, the upper part of the vacuum table was made for cutting samples for Iosipescu tests and dielectric tests. The article describes various types of tools for PCM processing and an experiment on the wear resistance of a diamond-like coated rasp cutter when milling carbon fiber reinforced plastic, carried out by foreign researchers.

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