Open Access
Access granted
Subscription Access
Vol 40, No 2 (2019)
- Year: 2019
- Articles: 14
- URL: https://ogarev-online.ru/1068-3666/issue/view/14182
Article
Structure, as well as the Tribological and Mechanical Properties, of Extrudable Polymer-Polymeriс UHMWPE Composites for 3D Printing
Abstract
In order to develop dispensable materials for additive manufacturing technologies, the structural and functional analysis of antifrictional polymer-polymer blends based on ultrahigh-molecular weight polyethylene (UHMWPE) are performed. The problem of the optimal selection of polymer plasticizers from the commercially available thermoplastic is solved in order to improve the extrudability of UHMWPE. It is shown that the effective plasticizing filler for UHMWPE from the standpoint of maintaining its tribological and mechanical characteristics and providing the required melt flow index is a double mixture of 10 wt % HDPE-g-SMA + 10 wt % PP. Using the developed materials will make it possible to manufacture parts of a complex shape for tribojoints, including endoprostheses, by the 3D printing method.
107-115
Improving the Wear Resistance of Carbon Fiber Reinforced Polyvinylidene Fluoride by the Method of Radiation Modification
Abstract
The effect of radiation modification on the wear resistance of carbon fiber reinforced polyvinylidene fluoride (PVDF) is studied. The radiation treatment is carried out through the radiation of accelerated electrons. It is found that the radiation modification of the composite led to a multiple increase in its wear resistance in dry friction on steel by several orders.
116-119
Investigation of Influence of Methods of Mixing Components on the Properties of Composites Based on PTFE and Carbon Fibers
Abstract
The results of a study on the development of tribological materials based on polytetrafluoroethylene and carbon-fiber-activated material of the UVIS-AK-P brand are presented. The effect of mixing technologies on the physicomechanical and tribological characteristics of polymer composites is studied.
120-127
Investigation of the Correlation between the Natural Extension Ratio and Abrasive Wear Resistance in Polyethylene
Abstract
The abrasive wear in different types of polyethylene assessed with different parameters of plastic failure. The parameter for the analysis of plastic failure is the natural extension ratio (NER). The correlation was determined between the wear and the NER. Larger values of the NER correspond to a higher value of wear. A significant relation between the NER and the dependence of wear on size of the grains is shown. The most probable explanation of this relation lies in the common mechanism of plastic failure during volumetric and contact loading.
128-132
Evaluation Method of Impact and Abrasive Steel Resistance
Abstract
A technique is developed for evaluating the impact-abrasive resistance of cast specimens, which allows simulating the conditions of impact and abrasive wear when changing the following factors: impact energy, abrasive impact angle, abrasive type, and its consumption and grain size. The complex experiment results for five carbide-promoting elements effect on abrasive (AR), impact and abrasive (IAR), and antifriction (AFR) steel resistance in the cast and hardened states are presented. The possibility of using the new technique for evaluating wear resistance and optimizing the composition of steel operating under impact-abrasive effects is shown.
133-138
Wear of a Flexible Abrasive Tool
Abstract
The paper discusses the results of a tool wear study included in evaluating the operational characteristics of a flexible abrasive tool (FAT). A correlation is established between a FAT’s wear values and various grinding conditions. The mechanisms of abrasive grain wear and degradation of the working layer of a FAT are studied. Experimental proof is obtained for choosing the optimal characteristics for the most common grinding operations in evaluating the quality of flexible abrasive tools for the purpose of developing usage recommendations and FAT machinability charts for various materials.
139-145
Oscillatory Processes under Friction in Materials and Coatings Based on Aluminum
Abstract
Oscillatory processes that occur in the course of friction in the audio frequency range are considered. Methodical approaches for observing them are proposed, and their connection with the processes of deformation and fracture occurring in thin surface layers is demonstrated. It is shown that under friction conditions, the analysis of oscillatory processes makes it possible to identify in time the stages of the deformation of the surface roughness and destruction occurring on the surface of the material under study.
146-150
Analysis of Frictional Resistance Arising at the Edge of the Sheet Metal Drawing Die
Abstract
The paper presents the results of the experimental studies of the frictional resistance of sheet metal used in the automotive industry in the process of its formation. The friction tests are carried out on a special installation designed to reproduce the friction resistance arising at the edge of the die during the metal sheet drawing. It is established that the friction factor can vary significantly in the process of sheet deformation. A comparative analysis of the experiment results and the finite-element sheet drawing simulation is carried out. It is shown that the developed finite-element model allows adequately determining the friction factor under large metal deformations.
151-155
Tribological and Rheological Properties of Thermally Treated Steel under Reverse Friction
Abstract
Changing the sclerometric parameters and acoustic emission activity of friction zones depending on the tempering temperature of carbon steel quenching under conditions of cyclic-reverse scratch-testing is studied. The tribological analog of the Baushinger effect, whose occurrence depends on the structure of steel tempering, is experimentally researched. The physical nature of Baushinger’s triboeffect as a rheological parameter of relaxation and the dissipative properties of the frictional contact are examined in connection with the acoustic emission activity and amplitude dependent internal friction of steel.
156-162
Comparison of Mechanical and Tribological Properties of Nitride and Oxynitride Coatings Based on Chrome and Zirconium Obtained by Cathodic Arc Evaporation
Abstract
The results of the investigation of the microstructure, crystal lattice parameter, roughness, microhardness, elasticity modulus, friction coefficient, specific volumetric wear, and adhesion strength for CrN, ZrN, Zr–O–N, and Cr–O–N coatings are presented. The coatings are formed by cathodic arc evaporation and have a cubic lattice. Addition of oxygen to the nitride CrN and ZrN coatings leads to the lattice parameter increasing and the crystallite size decreasing simultaneously. The oxynitride coatings, Cr–O–N and Zr–O–N, possess improved tribological properties in comparison with nitride coatings.
163-170
Investigation of the Fracture and Strength of a Compound with a Carbide Base of a Wear-Resistant Ion-Plasma Vacuum-Arc Ti–N, Ti–Al–N, Ti–Al–Cr–N, and Ti–Al–Ni–N Coatings by the Scratch Testing
Abstract
Comparative studies of the fracture behavior and adhesion strength during scratch testing of a wear-resistant ion-plasma vacuum-arc Ti–N, Ti–Al–N, Ti–Al–Cr–N, and Ti–Al–Ni–N coatings are carried out by the scratch test. The type of failure and the adhesion strength characteristics of the coatings based on LC1, LC2, and LC3 are determined by their structure, by the H 3/E 2 and H/E parameter values, and by the values of compressive macrostresses.
171-178
Wear of Dies of Bulk Straining According to Criteria of Low-Cycle Fatigue and Plastic Crushing
Abstract
Cyclically changing thermomechanical loads causing the stress–strain state of dies are part of the crushing mechanism of surface and crack propagation in stress concentration zones. In order to evaluate the maximum stresses causing the critical strains of a die, a mathematical model is developed making it possible to predict the durability of a die’s working parts. The durability of punches and matrixes is estimated by the average number of loading cycles up to the breakdown of the tool according to the criteria of low-cycle strength and plastic crushing.
179-187
Friction Features of a Rubber Surface Modified by a Carbon Coating
Abstract
The behavior of the friction coefficient for the initial and modified surface of butadiene-nitrile rubber with respect to a counterbody in the course of tribological tests is considered. The adhesion and hysteresis loss occurring under friction are estimated. It is shown that in the course of friction of the modified surface, the contribution of the loss of hysteresis to the friction coefficient is almost constant, whereas the adhesive component of the friction force exhibits an increase.
188-193
Tribological Features of Environmentally Safe Lubricant Compositions Based on Rapeseed Oil
Abstract
Different lubricants in terms of their nature and properties are studied using a four-ball friction machine and an SMT–1 friction machine. It is found that an environmentally safe lubricant based on rapeseed oil (RO) in comparison with lubricants made on the mineral base widely used in railway transport for rail and flange lubrication provides a lower wear level for conjugated solid bodies and a lower temperature in the friction zone. It is thus observed to have a more efficient protective and lubricating action. The latter is confirmed by the operational testing of the developed environmentally safe lubricant for a system of locomotive flange lubrication. It should be noted that the developed environmentally safe lubricant ensures not only better tribological characteristics but also is obviously distinguished by its environmental properties and biodegradability when used for the lubrication of wheel–rail friction pairs, since it is vegetable-based.
194-199