SU794033A1 - Method of making billets from filled fluoroplast-4 - Google Patents

Description

one

This invention relates to methods for processing compositions based on. Fluoroplast-4 with such fillers as bronze, lead, coke, molybdenum disulfide.

A known method for producing metal-plastic antifriction materials based on fluoroplast-4 with various PJ fillers.

The disadvantage of this method is low productivity, the finished material has low antifriction and physical and mechanical properties.

A known method for the manufacture of blanks based on fluoroplast-4 for the friction elements of compressors, including the preparation of initial components, the preparation of a press mass, pressing, thermal mechanical treatment C2.

The disadvantage of this method is low antifriction and friction co-mechanical properties of the resulting blanks.

The aim of the invention is to study the antifriction and physico-mechanical properties of the blanks.

The goal is achieved. In the manufacturing method

preparation of filled fluoroplast-4, including the operation of preparing fillers by grinding them and then mixing them with fluoroplast-4, the fillers are reduced from their oxides before they are mixed with fluoroplast-4. The reduction is carried out in a dissociated a 1 miac medium.

o

. The proposed method for manufacturing blanks based on fluoroplast-4 with fillers (bronze, lead, coke and molybdenum disulfide) consists of the following: preparation of components,

5 preparation of the press mass, pressing of the blanks and heat treatment (sintering and cooling of the blanks),

The preparation of the starting components is carried out as follows.

Fluoroplast-4 grind to 0.50 1.0 mm. Coke grind to 20 microns. Milled coke is mixed with lead oxide to obtain a homogeneous mixture and is reduced in dissociated ammonia at a temperature of 350 10 C for 3 hours / i.e. Lead is produced when reduced in dissociated ammonia from lead oxide. Bronze powder is restored in a dissociated environment.

ammonia at a temperature of 300 for .3 h to remove oxide film from the surface of the particles. Before preparing the press mass, the reduced components are mixed with molybdenum disulfide, which is taken in an amount sufficient to form a strong film on the surface of the particles of the reduced components, which prevents them from further oxidation and from reacting with fluoroplastic-4, ensuring high physical and mechanical properties .

Next, the mixture of components is poured into a mixer with crushed fluoroplast-4, and stirred for 5-6 minutes. The pressing of blanks is carried out in molds under pressure KGS / CM7, the exposure time under pressure of 40-60 s. Pre-compressed molds in the molds are evenly distributed on the shelves of the furnace, including heating. Sintering produces at temperature

350 5 C, the time required for the blanks at a given temperature is taken at the rate of 15 minutes per 1 mm of the height or thickness of the workpiece. The temperature difference throughout the furnace should be within. The cooling process to a temperature of 32 ° C is carried out at a rate of 1 hour per 10 mm of the height or thickness of the workpiece, further cooling is carried out in a closed furnace to 20-5 ° C with the heating turned off.

To compare the properties of the blanks obtained by the known and proposed methods, samples of materials of the same composition were made. The test results are shown in the table.

The proposed method allows

to obtain blanks with high antifriction and physicomechanical properties and capable of maintaining high elasticity with pressure drops up to 120 kgf / cm and speeds up to 1.5 m / s.

Claims (2)

Wear rate, kg / h (0.9-1.2) -10 (0.7-a, 8) Coefficient 0.39-0.44 0.36-0.38 friction Strength at tensile strength, MP a The modulus of elasticity in tension, relative elongation,% The modulus of elasticity in bending MPa Density, kg / m Thermal conductivity, W / MK / Temperature coefficient of linear expansion, K 85-100 80-100 500-600 2500 (5.5-6.5 ), 4-0,6) -10, 30-0.35 95-120 150-200 620-900. 2500 5.5-6.5) 1 to 5 79 Claims of the invention 1. A method for making fillings from filled fluoroplastic-4l including the steps of preparing fillers by grinding and post-mixing with fluoroplastic-4, in order to improve antifriction and physicomechanical properties of the preforms; before they are mixed with fluoroplastic-4, the fillers are reduced from their oxides, 36 2. The process according to claim 1 is distinguished by the fact that the reduction of the fillers is carried out in a dissociated ammonia medium. Sources of information taken into account in the examination 1. USSR author's certificate I 136540, cl. B 29 F 5/00, I960, 2. USSR author's certificate 298604, cl. C 08 L 27/18, 1964 (prototype).