CN1141899A - Sintered ceramic material and disk valve assembly - Google Patents

Abstract

A ceramics material for a sliding member used in the water or brought into contact with water is proposed. It is low in frictional resistance and high in wear resistance and shows a long life when used in such a condition. Also, a disk valve assembly is proposed which has a valve body and a valve seat having sliding surfaces that are high in sliding properties. By sliding the valve body on the valve seat having valve holes, the valve holes can be opened and closed. One of the valve seat and the valve body is made of a self-lubricating ceramics material comprising of an oxide ceramic as a main component, and at least one anti-friction agent selected from the group made up of iron, nickel, cobalt and their oxides, nitrides and carbides. The other of the valve seat and the valve body is made of an aluminum oxide ceramics material and has a larger slide contact area than the one of the valve seat and the valve body.

Description

Sintered ceramic material and disk valve assembly

It is low and be suitable as the sintered ceramic material of the sliding component under the water lubricating condition, show the sintered ceramic material of fabulous erosion resistance and the disk valve assembly of being made by this stupalith in corrosive environment or boiling water to the present invention relates to friction resistance.

The slip of the machine part of being made by sintered ceramic material or rolling member usually use to be had under oil film or the lubricated oil condition to reduce the friction resistance of sliding surface.

Up to now, it is deleterious using oily lubricant, in application, employing be by with impregnated silicon nitride one carborundum porous ceramics of the such solid lubricant of image-stone China ink, molybdenumdisulphide, boron nitride, fluoro-resin and paraffin (Japanese Patent of having examined open 5-50475).

High abrasion goods that some are traditional such as cutting tool are by the silicon nitride phase and the high-density auxiliary phase constitutes, hard refractory particles is dispersed in the composite component that two-phase matrix is wherein made.This refractory materials is selected from and resembles the such metal of titanium, molybdenum, tungsten and tantalum and their carbide and nitride (unexamined Japanese Patent 57-51175).

But for using in water or with the sliding component of water-wet, the sliding surface bearing of water pump for example usually can not the use oily lubricant.In this case, sliding component must use under unlubricated dose condition, so that the friction resistance of sliding surface tends to increase the life-span that will increase the needed impellent of mobile sliding component like this and shorten this sliding component.

Lack watertightness with the impregnated ceramic sliding member of the above-mentioned solid lubricant of mentioning because of their porous character.Therefore intensity is lower.In addition, these solid lubricants are very expensive, so manufacturing cost certainly will be high.Solid lubricant also hinders the sintering of pottery, is difficult to increase the density of sintered ceramic.

The composite component that the high-strength refractory particle is scattered in wherein also has several problems.A problem is the manufacturing cost height, because use expensive refractory metal and their compound.The compact agent of determining sintering condition such as sintering temperature and increase sintered ceramic density also is difficult.The sintered ceramic of Xing Chenging has high friction resistance like this.

The ceramic sliding member that in water, uses comprise use in acid, alkali and corrosive environment or boiling water mechanical sealing member, tubular liner and be immersed in protecting tube in the hot water.Concerning these ceramic components, need high erosion resistance.Therefore traditional such sliding component is by non-oxide ceramics, makes as silicon carbide.Sintered silicon carbon is the process of a complexity because it must be in rare gas element high temperature sintering.This sintered ceramic is to be difficult to produce in batches.Therefore people attempt to replace non-oxide ceramics with oxide ceramics that is not too expensive, easy-sintering.But oxide ceramics such as aluminum oxide are easily by acid and alkali corrosion.If the purity of this oxide ceramics is lowered to easy sintering, they will obviously corrode (1994 by Chiiin Shokan publication for " new ceramics ", 20-21 page or leaf).

First purpose of the present invention provides use in water or with a kind of sintered ceramic material of the sliding component of water-wet, this material friction resistance is low and wear resistance is high and when use long in this condition life-span in following time.

Second purpose of the present invention provides a kind of sintered ceramic material, and this material is to have the form of the oxide ceramics of erosion resistance of improvement such as aluminum oxide and can use in corrosive environment or boiling water.

Fig. 6 and Fig. 7 represent a kind of can be hot water and cold water mix traditional disk valve assembly together.

It is included in the bottom and is fixed on 1 li of valve cap and two base plates 2 that advance hole 3 and 4 (only expressing one) are arranged, advanced in hole filling collar- pecker 3a and 4a (only expressing).Valve seat 5 is overlayed on the base plate 2.It has valve opening 6 and 7 (only expressing) respectively with enter hole 3 and be connected with 4.Valve body 8 is placed on the valve seat 5 slidably.Valve body 8 is again by slip seal ring 9 and O shape ring 10 supporting lever bridge 11 rotatably.With lever bracket 11 bonded are the bottoms that are supported on the lever shaft 13 on the pin 12.Up and down or left-right rotation lever shaft 13 control lever 14, valve body 8 slides on valve seat 5, thereby changes the opening degree of valve opening 6 and 7.

Valve body 8 has two aquaporin 5a and 5b, and they are to form by the base cutting valve body 8 along it.Hot water and the cold water of introducing valve opening 6 and 7 through water-supply pipe enter the mixed chamber 15 of water then by opening valve opening inflow passage 5a and 5b separately.From the cold and hot water mixture of valve opening supply, warm water is transported to the faucet outlet of not expressing thus.

Unexamined Japanese patent publication 63-36765 discloses such disk valve.In order to improve the sliding capability of valve body 8, be to make one of in valve body 8 and the valve seat 5 by the resin with self lubricity such as fluoro-resin or ultra high molecular polyethylene, or made by the resin of the filler that comprises the oilness that can improve resin such as molybdenumdisulphide and carbon, and another is made by stupalith.

A problem of the valve body of being made by this self lubricity resin is its low creep resistant.Even fiber enhancer is added in the material of valve body, its waterproof ability is still so low so that only could prevent the sealing leakage under lower hydraulic pressure.

On the contrary, valve body or the enough hard and high water pressure resistance of making by stupalith of valve seat.Unexamined Japanese patent publication 4-351379 discloses a kind of disk valve assembly, and its valve body and valve seat are the sliding surfaces by alumina ceramic material is made and useful convex surface forms.

By valve body or valve seat frictional coefficient height on its sliding surface that alumina ceramic material is made, this will hinder the smooth operation of lever.Therefore, in order to reduce sliding resistance, on its sliding surface, form a convex surface.

In order to improve the operability of lever by convex surface of formation on the sliding surface at it at valve body or valve seat, this convex surface must be at least 5 μ m height.Yet high like this convex surface is difficult to that valve body is closely pressed to valve seat and anti-sealing leaks.

Unexamined Japanese patent publication 63-38722 proposes to use and makes valve body by a kind of porous material, and this porous material has the sliding capability that 200kg/mm2 or higher Vickers hardness and impregnated with lubricant improve sliding surface.

It is that lubricant tends to exhaust or flow out in use that but this valve body has a problem, so that the smooth motion of lever is along with the time can become more and more difficult.Its waterproof ability tends to reduce behind the life-time service.

People also know the ceramic valve that uses solid lubricant.For example, unexamined Japanese patent publication 6-48836 discloses a kind of valve body of being made by the silicon carbide-carbon ceramic material of self-lubricating.

Higher and the lubricant of this valve body wear resistance seldom can flow out.If but by adding sliding properties that a large amount of carbon improves it to the needed grade of disk valve, valve body can reduce on intensity and become more crisp.This valve body poor durability.

If particularly the valve seat that has big sliding contact area than valve body is to be made by this frangible material, so its sliding surface tend to wear and tear unevenly and since valve body wear and tear and roughen widely unevenly.Coarse like this surface will increase frictional coefficient or cause and leaks.

Therefore, even this traditional valve body and valve seat are to be made by the self-lubrication ceramic material, keeping their physical strength and sliding properties for a long time is difficult under the desired grade of disk valve.

So the 3rd purpose of the present invention provides the disk valve assembly of being made up of valve body and valve seat, this valve body and valve seat are to be made and kept sliding contact closely mutually so that they definitely can prevent the leakage of sealing or any other liquid for a long time by stupalith, keep frictional coefficient between them can make that valve body is smooth to be moved simultaneously.

According to first invention, it is by oxide ceramic material and be selected from the material of being made up of at least a low friction compound in iron, nickel, cobalt and their oxide compound, nitride and the carbide and form by sintering that a kind of sintered ceramic material, this sintered ceramic material of having higher sliding properties under the lubrication of water are provided.

Low friction compound reduces the sliding resistance of frictional coefficient and sliding surface under the water lubricating effect.Therefore, this sintered ceramic body is the sliding component that the utmost point is suitable for using in water, and it can prolong the life-span of sliding component.

In another scheme, provide with single-phase Al ₂O ₃The corrosion-resistant sintered ceramic material that solid solution exists, this sintered ceramic material sintering oxidation aluminium powder and iron or its hopcalite and form in atmosphere.

Iron or its oxide compound have increased coking property and density and have played low friction compound.Therefore this alumina sintered body can be as the sliding component in the etchant solution.

Low friction compound is cheap and without any need for special sintering method.Therefore, it is suitable for forming sliding component.

In order to solve the 3rd problem, valve seat and valve body are arranged according to disk valve of the present invention.Have at least one to be to make in them from the self-lubrication ceramic material of forming as the low friction compound main component and at least a chosen from Fe, nickel, cobalt and their oxide compound, nitride and the carbide by oxide ceramics.This valve body and valve seat are hard and have a high-wearing feature.Iron, nickel, cobalt and their oxide compound, nitride and the carbide that adds as low friction compound is used to the frictional coefficient that keeps lower.

A valve seat that forms valve opening is arranged and in order to open and to turn off valve opening and keep the valve body of sliding contact according to disk valve assembly of the present invention with valve seat, one of them that it is characterized in that valve body and valve seat is to make as the self-lubrication ceramic material of main component by comprising oxide ceramics, this oxide ceramics comprises at least a chosen from Fe, nickel, cobalt and their oxide compound, nitride and the carbide. low friction compound, another of valve body and valve seat is to be made by alumina ceramic material.

In addition, the area of the slipping plane of valve body of being made by the self-lubrication ceramic material or valve seat can be littler than the area of the slipping plane of valve body of being made by alumina ceramic material or valve seat.

Keep mutually at sliding surface on the valve body and valve seat of sliding contact, each sliding surface can form from raise to the center convex surface of 0.1-1 μ m height of the outward flange of each sliding surface, and the height sum that forms the convex surface of sliding surface is no more than 1.6 μ m.

If valve body or valve seat are by aluminum oxide (Al ₂O ₃) ceramic as main component, ferric oxide (Fe ₂O ₃) make as the alumina ceramic material of low friction compound, in the agglomerating process, the iron in the ferric oxide is distributed in the aluminium oxide particles densely with the form of solid solution.

When this valve body or valve seat contacted with water, when keeping sliding contact with coupling compoonent, the solid solution of being made up of aluminum oxide and iron was because the tribo-chemistry effect may be corroded the soft oxyhydroxide of generation ratio aluminum oxide matrix on sliding surface.Can think that these oxyhydroxide can reduce frictional coefficient.Can also think to have higher and avidity water,, therefore, further reduce frictional coefficient so the water that is present between valve body and the valve seat plays a kind of lubricant because form the stupalith of valve body and valve seat.

Be under the situation about making not only by the combination of aluminum oxide and ferric oxide at valve body or valve seat, and have in employing under the situation of minute metallic particle distribution general ceramic material therein of iron, nickel, cobalt and their oxide compound, nitride or carbide, water just can play a part a kind of lubricant in the above described manner.

Valve body or the valve seat made by above-mentioned stupalith have a convex surface on sliding surface, this convex surface from the outward flange to the center with the smooth rising of predetermined height.Convex surface works to reduce the contact area between valve body and the valve seat in this, thereby has further improved the oilness that produces owing to stupalith.Sliding resistance significantly reduces, so that valve body can move extremely glossily, prevents from simultaneously to leak.And this two specific character, promptly lower sliding resistance and higher waterproof ability can keep for a long time.

Valve body that is formed by the self-lubrication ceramic material and one of them of valve seat have above-mentioned composition and another is to be made by alumina-ceramic, and valve body can be more closely and the valve seat sliding contact, and keep the smooth operability of lever.

The valve seat that forms by self-lubrication ceramic material and one of them coupling compoonent of valve body than it with above-mentioned composition, i.e. valve seat or the valve body of making by alumina ceramic material, bigger sliding contact area is arranged, in this scheme, because it is to be made by soft material that the member of less sliding contact area is arranged, its sliding surface weares and teares equably, therefore keeps smooth.Make frictional coefficient keep lower thus.Water can not leak.

The convex surface that forms on the sliding surface of valve body has a successive surface not have interruption or opening at the center, and in this scheme, valve body and valve seat always contact with each other along a line rather than with point or small area.This can make valve body on valve seat to the smooth slip of all directions.Therefore the operability of lever improves.

By the following description of being done with reference to the accompanying drawings, characteristics of the present invention and purpose will become apparent:

Fig. 1 is illustrated in the content of the low friction compound in the sintered ceramic material and the graphic representation that concerns between the frictional coefficient under the dry lubricant condition;

Fig. 2 is the similar graph when using water as lubricant;

Fig. 3 is the longitudinal section of frictional dissipation trier;

Fig. 4 is Al ₂O ₃-Fe ₂O ₃The X-ray diffraction graphic representation of agglomerated material;

Fig. 5 is expression Al ₂O ₃-Fe ₂O ₃α-Al in the agglomerated material ₂O ₃Crystal (401) surface spacing and Fe ₂O ₃Content between graph of relation;

Fig. 6 is a kind of longitudinal section of disk valve assembly of scheme;

Fig. 7 A is the bottom plan view of the valve body of Fig. 6;

Fig. 7 B is the top plan view of the valve seat of Fig. 6;

Fig. 8 is illustrated in the convex surface figure that forms on the sliding surface of the valve body of this scheme and valve seat; With

Fig. 9 is to use the water in function test to mix the skeleton view of type tap.

Form according to the sintered ceramic oxide material of first invention mixture by sintered ceramic oxide (as Main Components) and anti-friction agent. The oxide ceramics that uses can be aluminium oxide or zirconia. The sintered ceramic material that forms like this keeps for a long time higher water proofing property and high wearability in water.

Anti-friction agent can be iron, nickel, cobalt or their oxide, nitride or carbide. It is dispersed in the sintered ceramic material or in the oxide ceramics particle form with solid solution exist. Although do not know its definite structure, it has reduced in the lip-deep wearability of sintered ceramic material when using when contacting with water. Therefore its slip life-span and other sliding capabilities are improved.

Be that aluminium oxide and anti-friction agent are the sintered alumina ceramic materials of iron or iron oxide for oxide ceramics, in sintering process, iron oxide (may be Fe₂O ₃) with form and the aluminium oxide (Al of solid solution₂O ₃) the particle combination. This has increased the density of sintered ceramic material. As aluminium oxide solid solution (α-Al₂O ₃) producing hydroxide when contacting with water, it has increased the affinity with moisture film, has therefore reduced coefficient of friction when this sintered ceramic slides.

Even iron, nickel or the cobalt particle of trace are dispersed in the sintered ceramic material, when contacting with water, also can reduce coefficient of friction.

In sintered ceramic material, the content of this anti-friction agent is preferably 1-30 % (by weight, " % " expression in describing in the back by weight). If be lower than 1%, coefficient of friction can not reduce fully. If be higher than 30 %, the intensity of sintered ceramic will reduce.

For the mixture from above-mentioned oxide ceramics and anti-friction agent forms this sintered ceramic material, pulverulent mixture is moulded to needed shape and sintering at high temperature. After sintered ceramic material is cooled, its slidingsurface of grinding-polishing and form sliding component. In order to increase the density of sintered ceramic material, can add a small amount of sintering aid. For alumina ceramic material, preferred sintering aid comprises silica (SiO₂), sodium oxide molybdena, calcium oxide (CaO) and magnesia (MgO). For zirconia ceramics material, yittrium oxide (Y₂O ₃) or magnesia (MgO) can be used as sintering aid.

By aluminium oxide (Al according to the ceramic material of second invention₂O ₃) powder (as oxide ceramic material) and iron or its hopcalite be shaped to needed shape, then sintering and single-phase α-Al of forming in atmosphere₂O ₃Solid solution.

It is with state of oxidation fusing or be phase-changed into solid solution in alumina substrate when iron or its oxide heat in oxidizing atmosphere. Cooled sintered ceramic material is single-phase α-Al basically fully₂O ₃, so it is at cold water or hot water or present higher corrosion resistance in acid or aqueous slkali.

Iron or its oxide be iron oxide preferably. Its content is defined as making sintered ceramic to contain single-phase α-Al₂O ₃And in sintered ceramic material with Fe₂O ₃Content meter be preferably 0.5-18%. If be less than 0.5%, α-Al₂O ₃Solid solution almost can not improve corrosion resistance. If be higher than 18%, iron oxide can not become solid solution fully, so that remaining iron oxide with wash-out out, reduces corrosion resistance.

Only just can determine that through X-ray diffraction test agglomerated material is whether by single-phase α-Al completely basically to this agglomerated material₂O ₃Solid solution is made. If the diffraction maximum of metallic iron or iron oxide does not appear on the curve map, this agglomerated material just has above-mentioned phase structure. Therefore this method is useful.

Concerning aluminium oxide, iron or its oxide play sintering aid. Namely separately can be at 1600 ℃ or relative superiority or inferiority sintering more when aluminium oxide, iron oxide is added wherein and can be sintered to sufficiently high density under about 1500 ℃ of lower temperature. Because liquid phase and solid phase be sintering all, so the strength increase of agglomerated material. And because material sintering in atmosphere, sintering step simply and with low cost carries out.

The iron that uses with aluminium oxide or its oxide are used as anti-friction agent. Like this, the sintering oxidation aluminum can be used as in water or the sliding component that in other words contacts with water. Namely can be as the sliding component that high corrosion resistance is arranged in acid, alkali and other etchant solutions according to the sintered alumina ceramic material of second invention.

Be a kind of ceramic material that comprises oxide ceramics matrix such as aluminium oxide according to the self-lubricating ceramic material for disc valve of the present invention, wherein disperseed micro-iron, nickel or cobalt or their oxide, nitride or carbide metallic. Namely use the sintered ceramic material according to first or second invention.

Be used for oxide ceramics of the present invention and comprise aluminium oxide (Al₂O ₃), mullite (can comprise 3Al₂O ₃、2SiO ₂-2Al ₂O ₃、SiO ₂, FeIII, Ti) and zirconia (ZrO₂). Be them and use the oxide ceramics in first or second invention identical. Their purity, shape and particle diameter are hard-core.

In order to make oxide ceramic material reach higher density when the sintering, its particle diameter distributes should be high as much as possible. On the other hand, for high resistance to sudden heating, its average particle size distribution is as far as possible little. Therefore, the average grain diameter of material preferably should be 3 μ m or less.

Employed anti-friction agent is to exist with small iron, nickel or cobalt or their oxide, nitride or carbide metallic as mentioned above. Their shape and diameter are without limits.

Anti-friction agent should add with the ratio of key component (oxide ceramics) weighing scale 1-30%. If be less than by weight 1%, the coefficient of friction of the material in the time of just can not fully reducing sintering. If surpass 30% by weight, the intensity of agglomerated material will reduce.

For the mixture from above-mentioned oxide ceramics and above-mentioned anti-friction agent forms ceramic component (sintered component), pulverulent mixture forms the shape of valve body and valve seat by the mould compression method. The powder that presses is sintering at high temperature. After the cooling, form slidingsurface thereon by grinding.

As mentioned above, can add the density that sinter additives improves sintered component with per 100 parts of weight self-lubrication ceramic 0.5-5 % weight.

Each valve seat and valve body should be from the smooth of the edge rising 0.1-1 μ m convex surfaces of slidingsurface and are had a slidingsurface, thereby should not surpass 1.6 μ m in the convex surface height summation that valve seat and valve body form. This is can not fully reduce friction because highly be lower than 0.1 μ m under the impact of rough surface (approximately 0.01-0.05 μ m). If any one in two convex surfaces is higher than 1 μ m, the contact-making surface of valve seat and valve body is too little and can not effectively prevent from leaking.

If the height summation of two convex surfaces surpasses 1.6 μ m, even the height of convex surfaces is in above-mentioned predetermined scope individually, the possibility of leaking also will increase. The needed power of operated valve (equaling substantially the needed power of operating lever) tends to be reduced to such scope so that with very little external force or even just can mobile valve by the weight of lever self. This will run counter to operator's wish and flow velocity is increased or reduce or open or close tap.

The below is described below with reference to the drawings the scheme according to disk valve assembly of the present invention.

Comprise that at the disk valve assembly shown in Fig. 6 and Fig. 7 the bottom is installed on the valve cap and the base plate 2 of two inlet holes 3 and 4 (only having one expresses) is arranged, and is filled with collar- pecker 3a and 4a (only having one expresses) in inlet hole. Valve seat 5 overlays on the base plate 2. It has two valve openings 6 and 7 (only having expresses) to link to each other with 4 with inlet hole 3 respectively. Valve body 8 is placed on the valve seat 5 slidably. Valve body 8 comes rotary support lever bracket 11 by sliding ring 9 and O type ring 10.

The bottom that is supported on the lever shaft 13 on the bolt 12 cooperates with lever bracket 11. By control lever 14 up and down or left rotation and right rotation lever bracket 13, valve body 8 slides at valve seat, in order to regulate the opening degree of valve opening 6 and 7.

Valve body 8 has two Aquaporin-5 a and 5b, and they are to form by the base cutting valve body along it. Then hot water and the cold water of introducing valve opening 6 and 7 through feed pipe enter the mixed chamber 15 of water by opening valve opening inflow passage 5a and 5b separately. Warm water namely from the hot and cold water mixture of valve opening supply, is transported to the faucet spout of not expressing thus.

Embodiment 1

Represent the alumina-ceramic sintered component with embodiment.As low friction compound, the metal iron powder of 0-30% weight, brown iron oxide (Fe ₂O ₃) or metal nickel powder (any one has 5 μ m or littler particle diameter among this three) be added in the aluminum oxide powder.Each mixtures of material is moulded to drum (external diameter 43mm, internal diameter 8mm and high 7mm).With the round tube type member that forms thus in sintering oven 1500-1600 ℃ of following sintering two hours.

The end face of this sintering round tube type member is polished so that surface roughness Ra is 0.05-0.1 μ m.The round tube type sample 24 that forms is thus carried out the friction, wear resistant test.

In these round tube type samples, some samples that contain iron powder sintering and other sintering in reducing atmosphere in atmosphere.Those that contain ferric oxide are sintering in atmosphere all.Those of nickel metal are sintering in reducing atmosphere all.

As shown in Figure 3, each round tube type sample 24 is installed in carries out the frictional dissipation test on the bracing member 23 of frictional testing machines, make its end face (slipping plane) 40 contact be installed in the end face 30 of the rotating disk 22 on the turning axle 21, and unlubricatedly rotating turning axle 21 down continuously with 4 meters/minute speed, applying constant load (it be 0.39MPa that contact surface is pressed) simultaneously between bracing member 23 and the turning axle 21, measuring the frictional coefficient under unlubricated (dried) condition.

Rotating disk 22 is to be made by sintered alumina, and its end face (slipping plane) 30 is through polished finish, as the slipping plane 40 of each sample 24.

With reference to Fig. 3, water receptacle 25 be installed in hermetically turning axle 1 around, contact with round tube type sample 24 sliding surfaces 40 with the sliding surface 30 of the water in the Bedpan 25 26 with the rotating disk 22 that supports by bearing 27.In this case, rotation turning axle 1 is to measure the frictional coefficient under the water lubricating condition.

The result of rub(bing)test form with the relation of the content of the low friction compound in the sintered ceramic member and frictional coefficient in Fig. 1 and 2 is represented.Frictional coefficient is along with the content of low friction compound is less under drying regime.As shown in figs. 1 and 2, although under the condition identical with the sample that contains iron powder sintering, the sample that contains 0% low friction compound has identical frictional coefficient basically under water lubricating and the condition of doing.This shows that simple water lubricating can not reduce frictional coefficient.

As shown in Figure 2, when containing 5% or more and up to the samples with water of 30% low friction compound when lubricated, frictional coefficient reduces significantly.Frictional coefficient is not significant different between the sample of the sample of the sample of containing metal iron, nickel metal and containing metal ferric oxide.In sintering oven, the frictional coefficient between oxidizing atmosphere and reducing atmosphere does not have remarkable influence yet.

Embodiment 2

Represented corrosion resistant alumina sintering member in this embodiment.

Aluminum oxide powder and brown iron oxide (Fe ₂O ₃) according to the mixed shown in the table 1.To make median size in grinding in ball grinder be 2.0 μ m or littler to the raw mix of Xing Chenging like this.In the raw mix that ground, add organic binder bond then and make the ball shape.Forming diameter by these pillers is that 20mm and length are the test sample of 10mm.In air after 600 ℃ of following roasting degreasings, immediately in atmosphere 1500 ℃ of following roastings two hours.This roasting method is traditional method.

Every kind of test sample is tested its erosion resistance in 5N hydrochloric acid and 5N sodium hydroxide solution and water.In at normal temperatures their immersion aforesaid liquids, do not see the test film obvious variation for a long time yet.Then, they are immersed in these liquid in autocrave, kept 120 ℃ simultaneously in three days.Measure the weight loss of the every kind of sample that causes owing to corrosion.

The result is illustrated in the table 1.

From table 1, contain the Fe of 1-10% obviously ₂O ₃The alumina sintering member aspect erosion resistance than pure alumina sintered component height, and add 20%Fe ₂O ₃Especially reduced erosion resistance to hydrochloric acid.

Test sample (test sample 2-5) is carried out the X-ray diffraction test.Diffraction curve figure is shown in Fig. 4.Containing 20%Fe ₂O ₃A1 ₂O ₃-Fe ₂O ₃Observe by Fe in the sintered component ₂O ₃The diffraction that crystal produces.But containing 10% or Fe still less ₂O ₃Sample in do not observe this diffraction.This fact shows that these samples come down to by single-phase α-Al ₂O ₃Make.Fig. 5 represents the α-Al by the X-ray diffraction measurement ₂O ₃The face of phase (104) spacing and Fe ₂O ₃Content between relation.Work as Fe ₂O ₃Content be increased at 20% o'clock, interplanar crystal spacing (104) increases.But at Fe ₂O ₃Content be higher than for 20% when zone, interplanar crystal spacing is constant.This fact shows Fe ₂O ₃Content be 18% or still less, the Fe of adding ₂O ₃Form with solid solution is melted in α-Al fully ₂O ₃Mutually, if but content surpasses 20% or higher, part Fe ₂O ₃May not fusion with Fe ₂O ₃The form of phase exists.These variations of crystalline structure are consistent with the corrodibility of the anti-hydrochloric acid of alumina sintering member.

Embodiment 3,4 and 13, Comparative Examples 1,5 and 6

The magnesium oxide of the silicon oxide of 4 parts of weight, 1 part of weight and the calcium oxide of 1 part of weight are mixed into a kind of material of formation in 90 parts of weight aluminum oxide powders and 10 parts of weight iron parts (100 parts of total amounts) as sintering aid, under drying regime, make the ball shape.These ball shape component dies be pressed into dish type as valve body (shape shown in Fig. 6 and the 7A) or dish type as valve seat (shape shown in Fig. 6 and the 7B).The disc-shaped component that forms was thus formed diameter 29.1mm and the dish type valve body of thick 9.6mm or the dish type valve seat of diameter 35.4mm and thick 4.0mm in two hours in 1600 ℃ of following roastings atmospheric pressure kiln.

Embodiment 5-8,14 and 15, Comparative Examples 2,7 and 8

4 parts of weight silicon oxide, 1 part of weight magnesium oxide and 1 part of weight calcium oxide are mixed into a kind of material of formation in 90 parts of weight aluminum oxide powders and 10 parts of weight ferric oxide parts (100 parts of total amounts) as sintering aid, under drying regime, make the ball shape.These ball shape component dies be pressed into disc-shaped component as with the valve body and the valve seat of above-mentioned disc-shaped component same size.The disc-shaped component that mold pressing is good forms valve body or valve seat with above-mentioned valve body or valve seat same size in 1600 ℃ of following roastings two hours atmospheric pressure kiln.

Embodiment 9-11,16 and 17, Comparative Examples 3 and 9

With 4 parts of weight silicon oxide, 1 part of weight magnesium oxide with 1 part of weight calcium oxide is mixed into 95 parts of weight aluminum oxide powders as sintering aid and 5 parts of weight ferric oxide parts (100 parts of total amounts) form a kind of material, under drying regime, make the ball shape.These ball shape component dies be pressed into disc-shaped component as with the valve body and the valve seat of above-mentioned disc-shaped component same size.The disc-shaped component that mold pressing is good forms valve body or valve seat with above-mentioned valve body or valve seat same size in 1600 ℃ of following roastings two hours atmospheric pressure kiln.

Embodiment 12 and 18, Comparative Examples 4

4 parts of weight silicon oxide, 1 part of weight magnesium oxide and 1 part of weight calcium oxide are mixed into a kind of material of formation in 80 parts of weight aluminum oxide powders and the 20 parts of weight nickel powders (100 parts of total amounts) as sintering aid, under drying regime, make the ball shape.These ball shape component dies be pressed into disc-shaped component as with the valve body and the valve seat of above-mentioned disc-shaped component same size.The disc-shaped component of mold pressing was formed valve body or valve seat with above-mentioned valve body or valve seat same size in two hours 1600 ℃ of following roastings in nitrogen atmosphere.

Comparative Examples 10

With 2 parts of weight B ₄C is mixed into as sintering aid and forms a kind of material in 100 parts of weight silicon carbide, makes the ball shape under drying regime.These ball shape component dies be pressed into disc-shaped component as with the valve body and the valve seat of above-mentioned disc-shaped component same size.The disc-shaped component that mold pressing is good forms valve body or valve seat with above-mentioned valve body or valve seat same size 2100 ℃ of following roastings one hour in nitrogen atmosphere.Then, on the sliding surface of valve body and valve seat, form convex surface with panel polishing machine polishing sliding surface with the described height of table 2.Then valve body and valve seat are immersed in the silicone oil.

As uniting the valve body and the valve seat of use with valve body that in the above embodiments and Comparative Examples, prepares and valve seat, or the valve body and the valve seat that use in 5 and 6 as a comparison case, valve body and valve seat that preparation is made by aluminum oxide.Further say, the silicon oxide of 4 weight parts and 1 part of weight magnesium oxide are mixed into as sintering aid form a kind of material in 100 parts of weight aluminum oxide, under drying regime, make the ball shape.These ball shape component dies be pressed into disc-shaped component as with the valve body and the valve seat of above-mentioned disc-shaped component same size.The disc-shaped component of mold pressing forms valve body or valve seat with above-mentioned valve body or valve seat same size 1600 ℃ of following roastings two hours in the normal temperature stove.

Then, polish the sliding surface of resulting valve body and valve seat, form from the edge smooth rising and have d1 and the convex surface of d2 (shown in Figure 8) height with polishing machine.Measure their surfaceness with the roughness trier.The result who measures is shown in the table 2.Their surfaceness (Ra) is 0.01-0.05 μ m.

The valve body and the valve seat that obtain are thus combined shown in table 2 and 3, in the disk valve assembly that every pair is installed in shown in Fig. 6 and 7, (simple lever, water mixes type water tap: KM300N, is made by KVK company).

The valve body and the valve seat that are installed in the disk valve assembly pass through the operability that waterproof ability and lever are measured in function/fatigue test.Test-results is in table 4 and 5 expressions.

Function/fatigue test

Before fatigue test, measure the operability (lever moment of torsion) of initial waterproof ability and lever.

Applying 17.5kgf/cm with water pump ²Pressure reach 30 seconds, keep simultaneously lever in low central position (at this moment cut off supply water) measure the hydraulic pressure drop-out value that causes owing to leaking afterwards, calculate waterproof ability thus.If voltage drop value is lower than 0.3kgf/cm ², can think that then this valve has qualified waterproof ability.

In lever torsional moment test, use machine for testing torsion (DFG-2K is made by Simpo Kogyo company) measure about (regulate water from zero to maximum) and about the needed moment of torsion of (adjusting water temperature) shift lever.If moment of torsion is to arrive in the 800gf scope 400, can think that then this valve assembly is qualified.If moment of torsion is less than 400gf, lever in use can move down automatically owing to gravity.When moment of torsion greater than 800gf, smooth shift lever is difficult.

The same protracted test machine of the lever of every kind of valve assembly that will use in initial trial (being made by NTN Engineering Plastics Corporation) cooperates and moves as shown in Figure 9, from upper-right position Ru (water supply stops) to position, bottom right Rd (cold feed), arrive lower-left Ld (boiling water then, 90 ℃), to upper left Lu (water stops), to lower-left Ld, to in following Cd (hot water, 45 ℃), to in go up Cu (water stops), in Cd (hot water, 45 ℃) down, to bottom right Rd (cold water), then to upper-right position Ru (water supply stops).This circulation (approximately using for 25 seconds) is repeated many times.To 200000 circulation times, measure the operability of their waterproof ability and lever.

Can obviously find out by table 4 and 5 results, in the Elementary Function test, satisfy the embodiment 3-18 of various conditions in the result who obtains aspect the operability of waterproof ability and lever.The result of fatigue test also is good.That is to say that after the test of 200000 cyclic fatigues, 0.3kgf/cm has only fallen in hydraulic pressure ²Or still less, and the operability of lever is good, promptly the lever moment of torsion is within the scope of 400-800gf.

On the contrary, for Comparative Examples 2,3,4 and 8, the convex surface both who forms on the sliding surface of valve body and valve seat is higher than the scope of regulation, although the lever operability is better, waterproof ability is relatively poor.

For Comparative Examples 1,2,4,7 and 9, the total height of the convex surface on valve body and valve seat surpasses 1.6 μ m, although its lever operability is better, waterproof ability is relatively poor.

For Comparative Examples 5 and 6, valve body and valve seat all are not to be made by self-lubrication ceramic, but are made by aluminum oxide, although slipping plane has the shape and the height of regulation, weather resistance is relatively poor.In fact, when testing campaign repeats 5000 times, the fatigue test of these Comparative Examples interruption because adhesion is had to.

Comparative Examples 10 is made and with silicone oil dipping, all is being poor aspect water-repellancy, lever operability and the weather resistance by silicon carbide ceramics.

Table 1

Test number	Composition (Wt%)		Corrosive liquid	Corrosion loss (mg/cm 2)
					????Al 2O 3	????Fe 2O 3
	????1	????100					????0	????NaOH?5N ????HCl?5N ????water	????5.65 ????2.63 ????1.25
????2			????99	????1	????NaOH?5N ????HCl?5N ????water	????0.35 ????0.76 ????0.00
	????3	????95					????5	????NaOH?5N ????HCl?5N ????water	????0.23 ????0.48 ????0.00
????4			????90	????10	????NaOH?5N ????HCl?5N ????water	????0.18 ????0.37 ????0.00
	????5	????80					????20	????NaOH?5N ????HCl?5N ????water	????0.31 ????8.49 ????0.00

1) these dip tests continue 3 days, and corrosive liquid remains on 120 ℃.

Table 2 Table 3

Table 4 ^★Units f/cm ^{2 ★ ★}The gf of unit table 5

^★Units f/cm ^{2 ★ ★}The gf of unit-test stops

Claims (11)

1. sintered ceramic material that with water lubricating the time, has higher sliding properties, said sintered ceramic material forms by a kind of material of sintering, and this material comprises oxide ceramic material and at least a chosen from Fe, nickel, cobalt and their oxide compound, nitride and carbide low friction compound.

2. the said sintered ceramic material of claim 1, wherein the content of said low friction compound is 1-30% by weight.

3. corrosion-resistant sintered ceramic material, it is to form by sintering oxidation aluminium powder and iron in atmosphere or its hopcalite.

4. single-phase α-Al ₂O ₃The corrosion-resistant sintered ceramic material of solid solution form, said sintered ceramic material are to form by sintering oxidation aluminium powder and iron in atmosphere or its hopcalite.

5. the described sintered ceramic material of claim 3, the content of wherein said iron or its oxide compound in sintered ceramic material with Fe ₂O ₃Content count 0.5-18% weight, and this material has higher sliding properties and higher acidproof and alkali resistance with water lubricating the time.

6. one kind has the valve seat that forms valve opening and keeps the disk valve assembly of sliding contact with the valve body that opens and closes said valve opening with said valve seat, it is characterized in that: at least one is by comprising that the self-lubrication ceramic material as at least a low friction compound of the oxide ceramics of main component and chosen from Fe, nickel, cobalt and their oxide compound, nitride and carbide makes in said valve seat and the valve body.

7. one kind has the valve seat that forms valve opening and keeps the disk valve assembly of sliding contact with the valve body that opens and closes said valve opening with said valve seat, it is characterized in that: one is by comprising that the self-lubrication ceramic material as at least a low friction compound of the oxide ceramics of main component and chosen from Fe, nickel, cobalt and their oxide compound, nitride and carbide makes in said valve seat and the valve body, and another of said valve body and valve seat made by alumina ceramic material.

8. the said disk valve assembly of claim 7, one of them of wherein said valve body and valve seat has less sliding contact area than another of said valve body and valve seat.

9. said disk valve assembly in any one of claim 6-8, wherein said oxide ceramics is an alumina-ceramic.

10. said disk valve assembly in any one of claim 6-9, wherein said valve body and valve seat have the slipping plane that keeps mutual sliding contact, said each sliding surface forms a kind of convex surface, this convex surface is from raise to the center height of 0.1-1 μ m of the outward flange of said each sliding surface, and the summation of the height of the said convex surface that forms on said sliding surface is no more than 1.6 μ m or littler.

11. said disk valve assembly in any one of claim 6-10, wherein forming said convex surface on the sliding surface of said valve seat has a centre portions at it not have the continuous face of interruption or opening.

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