SU1093950A1 - Lubricant plasticity evaluation method - Google Patents

Description

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The invention relates to a testing technique, in particular the evaluation of the rheological properties of lubricants,

A known method for evaluating the plasticity of a lubricant consists in placing a lubricant on a sample, acting on it with an indenter, applying a load to the latter, and registering a parameter characterizing the plasticity of the lubricant tH.

The disadvantage of this method is the lack of reliability of the results, due to the choice in quality of the parameter characterizing the plasticity of the lubricant, the number of penetration and the testing of the lubricant beyond the tensile strength.

The purpose of the invention is to increase the reliability of the results of evaluating the plasticity of a lubricant,

This goal is achieved by the fact that according to the method of evaluating the plasticity of a lubricant, which consists in placing a lubricant on a sample, acting on it with an indenter, applying a load to the latter and registering a parameter characterizing the plasticity of the lubricant, using a sample with a flat surface placed on the surface deformed under uniaxial compression n | 4 and variable loading, the moment of the limiting degree of deformability of the lubricant is fixed, and as a function the deformation dependence is the stress compression, which assess the plasticity of the lubricant. Figure 1 shows a device for carrying out a method for evaluating the plasticity of a lubricant; Fig. 2 is a graph of strain versus compressive stress. ;

 The device contains a table (not shown) with sample 1 for placing lubricant 2 on it, node 3 for detecting deformation of lubricant 2, node (not shown and loading sample 2 by means of indenter 4.

A method for evaluating the plasticity of a lubricant is carried out as follows.

Places the lubricant 2 on the sample 1. Act it on the indenter 4, apply the last load P and register a parameter characterizing the plasticity of the lubricant. In this case, a sample 1 with a flat surface is used, the lubricant 2 is deformed under uniaxial compression conditions under alternating loading, the moment of the maximum degree of deformability of the lubricant is recorded, and as a parameter, the dependence of the deformation on the compressive stress (Fig. 2) is determined. Torah assess the plasticity of the lubricant. ki

At m ° er. A lubricant with a different quantitative ratio of thickener and oil base lubricant is used (Fig. - lubricant based on lithium soap and mineral oil; 2 - 25% of oil is pressed; 3 - 40% of oil is pressed; 4 - 58% of oil is pressed. In this way, model real-life lubrication process

5 and a decrease in the amount of oil. Lubricant 2 is placed on. Sample 1. The indenter 4 is brought in contact with the lubricant. 2. Deform the lubricant under uniaxial conditions.

0 compression at variable loading and register continuously the amount of deformation with the help of the node 3. The test is carried out to achieve the maximum degree of deformability of the lubricant. With

5, the constant volume of lubricant to each value ii corresponds to the area of Si. For the value of P, the compressive stress Yen PviSi-According to the data of Si and 0 ,, the dependences are constructed (Fig. 2). A decrease in the amount of oil leads to a significant change in the plasticity of the lubricant: the area of imperfect plasticity decreases (creep, the stress of the onset of plasticity increases

5 f & f ff. P1xt of the zone of true plasticity decreases (the nature of plasticity in the zone changes, and the degree of depletion decreases, corresponding to the limit of the plastic state of the lubricant (point Bt).

 Number 4 (Lig. 2) behaves like a solid body; at point D the fragile destruction of the lubricant occurs.

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The positive effect is due to the reliability of the coupling of the plasticity of the lubricant by determining the creep zone, the voltage of the beginning of the true plastic flow: and the zone of this flow, the amount of deformation at the beginning and the end, the zone of plastic flow, which allows to diagnose the state of lubricants when working in the nodes friction, to predict their performance, - as a result, the reliability and durability of the engineering products is increased reliably.

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Claims (1)

(571 METHOD FOR ESTIMATING LUBRICITY PLASTICITY, which consists in placing lubricant on a sample, acting on it with an indenter, applying a load to the latter and registering a parameter characterizing the plasticity of the lubricant, characterized in that, in order to increase the reliability of the results, use a sample with with a flat surface, the lubricant placed on the surface is deformed under uniaxial compression under variable loading, the moment of the limiting degree of deformability of the lubricant is recorded, and the dependence for Compression stress information, which assesses the plasticity of a lubricant.