CN107285748A - A preparation method of ceramic composite material for emulsification pump plunger - Google Patents

Abstract

A kind of preparation method for being used to emulsify the ceramic composite of pump plunger, aluminum oxide, hexagonal boron nitride, magnesia, calcium oxide, diopside are sufficiently mixed first, granulated after being sufficiently mixed again with mullite crystal whisker, powder is placed in hydrostatic pressing in mould, sintered into the aluminium oxide ceramics plunger blank of densification again, finally by grinding into the ceramic plunger with precise measure and precision；Compared with prior art, ceramic plunger material of the invention can effectively improve the toughness of ceramic plunger, reduce the coefficient of friction of plunger, improve the grinding type and yield rate of material, improve the service life of ceramic plunger.

Description

A preparation method of ceramic composite material for emulsification pump plunger

technical field

The invention relates to the field of preparation of ceramic composite materials, in particular to a preparation method of ceramic composite materials used for emulsification pump plungers.

Background technique

Emulsion pump station is one of the key equipments in fully mechanized mining face, and its normal operation directly affects the production efficiency of high-yield and high-efficiency working face. Due to the long working cycle of the emulsion pump, the quality requirements for its key component, the ceramic plunger, are quite strict.

From the comparison of wear resistance, zirconia ceramics are twice that of toughened alumina ceramics, and the toughened alumina ceramics are more than 4 times that of alumina ceramics; compared from the perspective of fracture toughness, zirconia ceramics are toughened alumina ceramics 2-3 times that of alumina ceramics, and the toughened alumina ceramics are about 2 times that of alumina ceramics. The performance of zirconia ceramics is most suitable for the conditions of use in coal mines, but from an economic point of view, zirconia ceramics are expensive and cost-effective, and alumina ceramics are cheap but not wear-resistant and tough enough. Therefore, the choice of toughened alumina ceramics for the plunger material of the emulsion pump is the most reasonable, and the plunger may generate local instantaneous heat during the movement, and the toughened alumina ceramics are more stable than zirconia at high temperatures.

Whiskers are ceramic single crystals with a certain aspect ratio (diameter 0.1-1.8um, length 35-150um) and few defects. With high strength, it is a very good toughening reinforcement of ceramic matrix composite materials; the fiber length is several times longer than that of ceramic whiskers, and it is also a good ceramic toughening body, and the two can be combined and practical. Use SiC, Si3N4 and other whiskers or C, SiC and other long fibers to compound and toughen alumina ceramics. The addition of whiskers or fibers can increase the fracture surface, which increases the crack propagation channel. When the remaining energy of the crack propagation penetrates into the fiber (whisker), when the fiber (whisker) is pulled out, debonded and fractured, the fracture energy is consumed or the crack propagation direction is deflected, etc., so that the toughness of the composite material is improved. . However, when the content of whiskers and fibers is high, densification becomes difficult due to its arch bridge effect, resulting in a decrease in density and performance.

For the ceramic plunger of the emulsification pump, the sliding friction and wear between the plunger and the sealing ring is an important factor affecting the sealing, and the lubrication between the plunger and the sealing ring is an important means to reduce the friction coefficient.

Contents of the invention

In order to overcome the above-mentioned shortcoming of the prior art, the object of the present invention is to provide a kind of preparation method of the ceramic composite material that is used for emulsification pump plunger, added the mullite whisker that can play toughening effect in raw material, play The lubricating hexagonal boron nitride and various sintering aids to improve the sintering compactness can effectively improve the sintering compactness, toughness and lubricity of the alumina ceramic plunger.

In order to achieve the above object, the technical scheme that the present invention takes is:

A method for preparing a ceramic composite material for emulsification pump plunger, comprising the following steps:

Step 1; modulation of forming powder:

The alumina powder is fully mixed with hexagonal boron nitride, magnesium oxide, calcium oxide, and diopside, and then fully mixed with mullite whiskers, and the obtained powder is granulated; the granulated powder includes the following Components and parts by weight: 65-90 aluminum oxide, 2-6 hexagonal boron nitride, 1-3 magnesium oxide, 1-5 calcium oxide, 1-5 diopside, and 5-20 mullite whiskers.

Step 2: isostatic pressing;

The mixture particles obtained in step 1 are placed in a mold for cold isostatic pressing, the forming pressure is 200-500MPa, and the holding time is 1-10min, and the obtained green body is directly roughed;

Step 3: high temperature sintering;

Sintering the obtained roughly machined green body at a high temperature to form a densified aluminum composite material green body, and the high temperature sintering temperature is 1500-1600°C. ;

Step 4: Grinding process;

The dense alumina composite ceramic plunger body is ground and processed into a ceramic plunger.

The mold in the second step is composed of an oil-resistant rubber sleeve, a porous cage, a mandrel and a rubber plug.

Beneficial effects of the present invention:

The invention has the advantages of effectively improving the compactness and processing efficiency of alumina ceramics, improving the fracture toughness and lubricity of the plunger, and realizing the preparation of alumina ceramic plungers with high density, good toughness, excellent lubricity and high dimensional accuracy For the purpose of using this kind of dense alumina ceramic plunger as the core component of the plunger pump, it has the advantages of long service life, wear resistance and low friction coefficient, reduces the number of times of shutdown maintenance and replacement of plunger and seal sleeve, and saves engineering operation cost, can also be extended to other alumina components.

At the same time, due to the addition of hexagonal boron nitride, the machinability of the material is effectively improved, and the production efficiency of grinding is improved. After grinding, the tolerance range of diameter and roundness is <0.01mm, and the surface finish is 0.2.

detailed description

The present invention is further described below.

Embodiment one

The preparation method of the present embodiment comprises the following steps:

Step 1; modulation of forming powder:

Fully mix alumina powder with hexagonal boron nitride, magnesium oxide, calcium oxide, and diopside, and then fully mix with mullite whiskers. The obtained powder is fully ball-milled and mixed with water in a ceramic container, and sprayed Granulator dry granulation; formulate according to the following parts by weight:

Step 2: isostatic pressing;

Put the mixture particles obtained in step 1 into a special forming mold consisting of a mandrel, an oil-resistant rubber sleeve, a porous cage and a rubber plug, seal it and put it into an oil cylinder of a cold isostatic press, and keep Press for 5 minutes to form; after demoulding, rough rough machining is carried out first;

Step 3: high temperature sintering;

Sinter the obtained rough-processed green body at high temperature into a densified aluminum composite material green body, and keep it warm for 180 minutes at a sintering temperature of 1550 degrees;

Step 4: Grinding process;

The dense alumina composite ceramic plunger body is roughly ground and finely ground to make a dense alumina ceramic plunger; the relative density is 99.2%, the diameter tolerance is 0.005-0.01mm, and the surface roughness is 0.2.

Embodiment two

The preparation method of the present embodiment comprises the following steps:

Step 1; modulation of forming powder:

Fully mix alumina powder with hexagonal boron nitride, magnesium oxide, calcium oxide, and diopside, and then fully mix with mullite whiskers. The obtained powder is fully ball-milled and mixed with water in a ceramic container, and sprayed Granulator dry granulation; formulate according to the following parts by weight:

Step 2: isostatic pressing;

Put the mixture particles obtained in step 1 into a special forming mold consisting of a mandrel, an oil-resistant rubber sleeve, a porous cage and a rubber plug, seal it and put it into an oil cylinder of a cold isostatic press, and keep Press for 10 minutes to form; after demoulding, rough rough machining is carried out first;

Step 3: high temperature sintering;

Sinter the obtained rough-processed green body at high temperature into a densified aluminum composite material green body, and keep it warm for 180 minutes at a sintering temperature of 1530 degrees;

Step 4: Grinding process;

The dense alumina composite ceramic plunger body is roughly ground and finely ground to produce a dense alumina ceramic plunger; the relative density is 99.5%, the diameter tolerance is 0.005-0.01mm, and the surface roughness is 0.2.

Embodiment three

The preparation method of the present embodiment comprises the following steps:

Step 1; modulation of forming powder:

Fully mix alumina powder with hexagonal boron nitride, magnesium oxide, calcium oxide, and diopside, and then fully mix with mullite whiskers. The obtained powder is fully ball-milled and mixed with water in a ceramic container, and sprayed Granulator dry granulation; formulate according to the following parts by weight:

Step 2: isostatic pressing;

Put the mixture particles obtained in step 1 into a special forming mold consisting of a mandrel, an oil-resistant rubber sleeve, a porous cage and a rubber plug, seal it and put it into an oil cylinder of a cold isostatic press, and keep Press for 3 minutes to form; rough rough machining after demoulding;

Step 3: high temperature sintering;

Sinter the obtained rough-processed green body at high temperature into a densified aluminum composite material green body, and keep it warm for 180 minutes at a sintering temperature of 1580 degrees;

Step 4: Grinding process;

The dense alumina composite ceramic plunger body is roughly ground and finely ground to make a dense alumina ceramic plunger; the relative density is 98.5%, the diameter tolerance is 0.005-0.01mm, and the surface roughness is 0.2.

Embodiment four

The preparation method of the present embodiment comprises the following steps:

Step 1; modulation of forming powder:

Fully mix alumina powder with hexagonal boron nitride, magnesium oxide, calcium oxide, and diopside, and then fully mix with mullite whiskers. The obtained powder is fully ball-milled and mixed with water in a ceramic container, and sprayed Granulator dry granulation; formulate according to the following parts by weight:

Step 2: isostatic pressing;

Put the mixture particles obtained in step 1 into a special forming mold consisting of a mandrel, an oil-resistant rubber sleeve, a porous cage and a rubber plug, seal it and put it into an oil cylinder of a cold isostatic press, and keep it Press for 1 minute to form; after demoulding, perform rough machining on the blank;

Step 3: high temperature sintering;

Sinter the obtained rough-processed green body at high temperature into a densified aluminum composite material green body, and keep it warm for 180 minutes at a sintering temperature of 1500 degrees;

Step 4: Grinding process;

The dense alumina composite ceramic plunger body is roughly ground and finely ground to produce a dense alumina ceramic plunger; the relative density is 99.0%, the diameter tolerance is 0.005-0.01mm, and the surface roughness is 0.2. Embodiment five

The preparation method of the present embodiment comprises the following steps:

Step 1; modulation of forming powder:

Fully mix alumina powder with hexagonal boron nitride, magnesium oxide, calcium oxide, and diopside, and then fully mix with mullite whiskers. The obtained powder is fully ball-milled and mixed with water in a ceramic container, and sprayed Granulator dry granulation; formulate according to the following parts by weight:

Step 2: isostatic pressing;

Put the mixture particles obtained in step 1 into a special forming mold consisting of a mandrel, an oil-resistant rubber sleeve, a porous cage and a rubber plug, seal it and put it into an oil cylinder of a cold isostatic press, and keep Press for 8 minutes to form; after demoulding, rough rough machining is carried out first;

Step 3: high temperature sintering;

Sinter the obtained rough-processed green body at high temperature into a densified aluminum composite material green body, and keep it warm for 180 minutes at a sintering temperature of 1600 degrees;

Step 4: Grinding process;

The dense alumina composite ceramic plunger body is roughly ground and finely ground to make a dense alumina ceramic plunger; after rough grinding and fine grinding, a dense alumina ceramic plunger is made; the relative density is 99.3%, and the diameter tolerance 0.005-0.01mm, surface roughness 0.2.

Claims (1)

1. a kind of preparation method for being used to emulsify the ceramic composite of pump plunger, it is characterised in that comprise the following steps：

Step one；Shape the modulation of powder：

Filled again with mullite crystal whisker after alumina powder is sufficiently mixed with hexagonal boron nitride, magnesia, calcium oxide, diopside Divide mixing, obtained powder is granulated；Described granulation powder includes following components and parts by weight：Aluminum oxide 65-90, six Square boron nitride 2-6, magnesia 1-3, calcium oxide 1-5, diopside 1-5, mullite crystal whisker 5-20；

Step 2；Isostatic pressing；

The compound particles obtained in step one are placed in cold isostatic compaction in mould, forming pressure 200-500MPa, pressurize Time, 1-10min obtained base substrate；

Step 3；High temperature sintering；

Obtained base substrate is carried out to be sintered at high temperature into densification aluminium composite material base substrate, high temperature sintering temperature is 1500-1600 DEG C；

Step 4；Grinding；

By compact aluminum oxide composite ceramic plunger piston base substrate grinding into ceramic plunger.