CN101169188A - Silicon carbide ceramic seal ring - Google Patents

Abstract

The invention relates to a silicon carbide ceramic seal ring, which is characterized in that the seal ring is made with 0.5 micrometer nano-materials according to the following weight percentages: W0.5 nanometer micropowder, 85-95 percent; boron carbide powder, 2-9 percent; and liquid-gas resin, 2-8 percent. The manufacture technology is ultra-high temperature sintering, which includes the following procedures: weighing raw materials according to the weight percentages; putting the materials into a ball mill for ball milling; performing hydrochloric acid soaking, drying, crushing and sifting; pressing the obtained compound into a seal ring and charging; vacuumizing to be lower than 1Pa; raising the temperature at a rate of 700-900 DEG C per hour and stopping vacuumizing; filling with argon to normal pressure and stopping gas feed; continuing to raise the temperature and keeping 13-17 minutes at 1910-1930 DEG C; keeping the pressure in the furnace hearth at 0.01MPa, and raising the temperature to 2170-2200 DEG C and keeping the temperature for 50-70 minutes; turning off the furnace and allowing to cool naturally. The invention has the advantage that the seal ring is resistant to high temperature, high pressure and strong corrosion, and the reliability is high.

Description

A kind of ceramic sealing cup contg, silicon carbide

Technical field

The present invention relates to a kind of ceramic sealing cup contg, silicon carbide, can be used for the seal arrangement of various rotating speeds such as high temperature, high pressure, high rotating speed, deep-etching, pressure, medium, belong to the seal ring technical field.

Background technique

Seal ring is a kind of vital part that is widely used in seal arrangement, is directly connected to the using scope and the life-span of sealing, and the mechanical seal of its configuration is used for each field such as space flight, oil, chemical industry, machinery, food, pharmacy, automobile in a large number.Initial, the seal ring material of domestic common employing mainly contains cemented carbide, aluminium oxide, graphite, silicon nitride etc., with seal ring short, the poor reliability in working life of these material, and uses limitation, can not use under the high parameter condition.

Adopt the silicon carbide reaction-sintered technology later on, the Recipe of conventional silicon carbide reaction-sintered seal ring, combine by W14, W10 carborundum powder, graphite and additive formulations, form through working procedure processing such as compacting, pre-burning, Vehicle Processing, whole burning, mill processing, grindings, sintering temperature is 1500 ℃, will add 1: 1.15 metal silicon chip auxiliary material during sintering.The major defect of silicon carbide reaction-sintered is:

1, disposable siliconising has not only taken the useful space of stove, has reduced output, and has increased industrial residue, influences environmental protection;

2, carborundum content is lower, and purity difference, and contents of free si height are not corrosion-resistant, can influence food security if merge in food, medicine the inside;

3, its comprehensive mechanical physical index is lower, can not be applied to the operating mode of high temperature, high pressure, deep-etching and the sealing of medium, also is not suitable for the food and medicine industry.

Summary of the invention

The objective of the invention is to invent a kind of ceramic sealing cup contg, silicon carbide that can be applicable to high temperature, high pressure, deep-etching operating mode and medium.

For realizing above purpose, technological scheme of the present invention provides a kind of ceramic sealing cup contg, silicon carbide, it is characterized in that, adopts the nanometer materials of 0.5 μ m, and it is made by following raw materials by weight percent:

W0.5 nanometer micro mist 85%-95%

Boron carbide powder 2%-9%

Liquid gas resin 2% ~ 8%.

Described W0.5 nanometer micro mist is the miropowder of silicon carbide in submicro level of 0.5 μ m; Described liquid gas resin is a liquid phenolic resin.

A kind of manufacturing process of ceramic sealing cup contg, silicon carbide is characterized in that, adopts the superhigh temperature sintering process, and its technology is as follows:

One, material processed

(1) weighs raw material by weight percentage;

(2) raw material that weighs is put into the pebble mill ball milling;

(3) be to soak 20-40 minute in the hydrochloric acid of 70%-90% the composition behind the ball milling in concentration;

(4) composition is dried, pulverizes, sieved, reach 150 ~ 250 orders;

(5) composition is pressed into seal ring, 1.1 tons/cm of its pressure ³-1.3 tons/cm ³,

Density 1.85 gram/cm ³-2.05 gram/cm ³

Two, sintering

(1) shove charge is evacuated to less than 1Pa;

(2) the 700 ℃/h-950 ℃/h that heats up stops vacuum;

(3) applying argon gas stops to supply gas to normal pressure;

(4) continue to heat up,, keep burner hearth air pressure 0.01MPa, rise to 2170 ℃-2200 ℃ insulations 50-70 minute 1910 ℃-1930 ℃ insulations 13-17 minute;

(5) close stove, natural cooling;

(6) come out of the stove, clear up, grind processing, grinding, check, warehouse-in.

Described seal ring external diameter is  8mm- 500mm.

The present invention adopts submicron order α-sic covalent compound material of 0.5 μ m, adopts the superhigh temperature sintering process, has improved the quality of product, and its advantage is:

1, carborundum content height illustrates the purity height of its material.Can use at the medium of deep-etching, otherwise contents of free si drops to significantly≤1%, can use at media such as food, medicines;

2, flexural strength height can be indeformable under high temperature, high pressure operating mode, can be at pressure greater than 6MPa, and report under the condition of 50mm/s and reliably use;

3, hardness height, because its hardness reaches HS more than 110, the running that makes it under high-speed condition is not is not worn and torn, and has improved the reliability of working life and equipment;

4,, and can make heat-resisting, wear-resisting important mechanical parts such as axle sleeve, bearing shell, bearing, nozzle because it is a kind of nonmetallic material, and its use field is not only in mechanical seal;

5, owing to use reliably, reduce and reveal, the protection environment reduces service cycle, and can replace fully by rare metals such as tungsten, cobalt, nickel is the hard alloy seal ring of raw material making, has saved a large amount of national strategy goods and materials, and very big social benefit is arranged.

Figure of description

Fig. 1 is the silicon carbide micro-powder molecular structural formula;

Fig. 2 is a liquid gas resinous molecular structure formula.

Embodiment

The invention will be further described below in conjunction with embodiment.

Embodiment

A kind of ceramic sealing cup contg, silicon carbide, by 90 parts of W0.5 miropowder of silicon carbide in submicro level, molecular formula be α-sic, structural formula shown in 1 figure: 6 parts of boron carbide powders, 4 parts of materials of weight proportions of liquid gas resin are made, described liquid gas resin is the thermosetting property resol, the concrete trade mark is NB-615, its main component is a phenolic resin, and molecular formula is [C ₈H ₈O ₂] _n, structural formula as shown in Figure 2.

Its manufacturing process is as follows:

One, material processed

1, weighs raw material by weight percentage;

2, the raw material that weighs is put into the pebble mill ball milling;

3, be to soak 30 minutes in 80% the hydrochloric acid the composition behind the ball milling in concentration;

4, composition dried, pulverize, sieving reaches 200 orders;

5, composition is pressed into seal ring, 1.2 tons/cm of its pressure ³, density 1.95 gram/cm ³

Two, sintering

1, shove charge is evacuated to less than 1Pa;

2, the 700 ℃/h-950 ℃/h that heats up stops vacuum;

3, applying argon gas stops to supply gas to normal pressure;

4, continue to heat up,, keep burner hearth air pressure 0.01MPa, rise to 2180 ℃ of insulations 60 minutes 1920 ℃ of insulations 15 minutes;

5, close stove, natural cooling;

6, come out of the stove, clear up, grind processing, grinding, check, warehouse-in.

The ceramic sealing cup contg, silicon carbide of external diameter  8mm- 500mm can be made, also heat-resisting, wear-resisting important mechanical parts such as axle sleeve, bearing shell, bearing, nozzle can be made.

The present invention makes performance test according to GB/T 6569-86 " engineering ceramics bending strength test method ", and the key technical indexes sees Table

The technical order table

Sequence number	Technical parameter	Unit	JB/T6374-92 numerical value	International numerical value	The present invention detects numerical value	Conventional seal ring
							1	Volume density	g/cm 2	2.95-	≥3.00	3.15	2.95-3.10
2	Apparent porosity	％	≤0.3	＜0.3	0.20	＜0.3
							3	Hardness	HRA(	≥100	≥105	110	＞88(100)
4	Flexural strength	MPa	＞300	≥320	366	＞300
							5	Carborundum content	％	≥95	＞96	98	85-90
6	Contents of free si	％	≤1	＜1	0.70	10-15

Claims (5)

1. a ceramic sealing cup contg, silicon carbide is characterized in that, adopts the nanometer materials of 0.5 μ m, and it is made by following raw materials by weight percent:

W0.5 nanometer micro mist 85%-95%

Boron carbide powder 2%-9%

Liquid gas resin 2%-8%.

2. a kind of ceramic sealing cup contg, silicon carbide according to claim 1 is characterized in that, described W0.5 nanometer micro mist is the miropowder of silicon carbide in submicro level of 0.5 μ m.

3. a kind of ceramic sealing cup contg, silicon carbide according to claim 1 is characterized in that, described liquid gas resin is a liquid phenolic resin.

4. the manufacturing process of a ceramic sealing cup contg, silicon carbide is characterized in that, adopts the superhigh temperature sintering process, and its technology is as follows:

One. material processed

(1) weighs raw material by weight percentage;

(2) raw material that weighs is put into the pebble mill ball milling;

(3) be to soak 20-40 minute in the hydrochloric acid of 70%-90% the composition behind the ball milling in concentration;

(4) composition is dried, pulverizes, sieved, reach the 150-250 order;

(5) composition is pressed into seal ring, 1.1 tons/cm of its pressure ³-1.3 tons/cm ³,

Density 1.85 gram/cm ³-2.05 gram/cm ³

Two. sintering

(1) shove charge is evacuated to less than 1Pa;

(2) the 700 ℃/h-950 ℃/h that heats up stops vacuum;

(3) applying argon gas stops to supply gas to normal pressure;

(4) continue to heat up,, keep burner hearth air pressure 0.01MPa, rise to 2170 ℃-2200 ℃ insulations 50-70 minute 1910 ℃-1930 ℃ insulations 13-17 minute;

(5) close stove, natural cooling;

(6) come out of the stove, clear up, grind processing, grinding, check, warehouse-in.

5. ceramic sealing cup contg, silicon carbide according to claim 1 and 2 is characterized in that, described seal ring external diameter is  8mm- 500mm.