阅读说明：本技术 一种耐磨陶瓷叶轮及其制造方法 (Wear-resistant ceramic impeller and manufacturing method thereof ) 是由 肖琼 张迎启 于 2019-09-20 设计创作，主要内容包括：本发明公开了一种耐磨陶瓷叶轮,包括前盖板、后盖板和叶片,所述叶片包括嵌入所述前盖板或/和后盖板设置的预烧结陶瓷块；所述预烧结陶瓷块上设有嵌入部,前盖板或/和后盖板上设有与预烧结陶瓷块的嵌入部相嵌合的凹腔,所述嵌入部与凹腔两者的轮廓相适应。本发明还提供了一种耐磨陶瓷叶轮的制造方法。本发明的耐磨陶瓷叶轮及其制造方法,属于回转动力泵设备技术领域,耐磨性能更好、有较好抗汽蚀性能、成本适当、易于大型化,在叶片的工作表面设置耐磨性更好、表面更光滑的预烧结陶瓷块,有利于提高叶轮的抗汽蚀性能,提高泵的效率,预烧结陶瓷块沿叶轮的轴向伸入前盖板或后盖板内,有利于预烧结陶瓷块的固定,有利于提高叶轮强度。(The invention discloses a wear-resistant ceramic impeller, which comprises a front cover plate, a rear cover plate and blades, wherein the blades comprise pre-sintered ceramic blocks embedded into the front cover plate or/and the rear cover plate; the pre-sintered ceramic block is provided with an embedded part, the front cover plate or/and the rear cover plate is/are provided with a concave cavity embedded with the embedded part of the pre-sintered ceramic block, and the embedded part and the concave cavity are matched in outline. The invention also provides a manufacturing method of the wear-resistant ceramic impeller. The invention relates to a wear-resistant ceramic impeller and a manufacturing method thereof, belonging to the technical field of rotary power pump equipment, wherein the wear-resistant ceramic impeller has better wear resistance, better cavitation resistance, proper cost and easy large-scale production.)

1. A wear-resistant ceramic impeller comprising a front cover plate (100), a back cover plate (300) and a blade (200), characterized in that the blade (200) comprises a pre-sintered ceramic block (201) embedded in the front cover plate (100) or/and the back cover plate (300); the pre-sintered ceramic block (201) is provided with an embedded part, the front cover plate (100) or/and the rear cover plate (300) is/are provided with a concave cavity embedded with the embedded part of the pre-sintered ceramic block (201), and the embedded part and the concave cavity are matched in outline.

2. A wear-resistant ceramic impeller according to claim 1, characterized in that the vane (200) further comprises a vane connecting part (202) which is formed by sintering the front cover plate (100) and the back cover plate (300) at one time and is arranged between the front cover plate (100) and the back cover plate (300), and the vane connecting part (202) is adapted to the back side of the pre-sintered ceramic block (201); the pre-sintered ceramic block (201) is embedded into the front cover plate (100) or/and the rear cover plate (300) along the axial direction of the impeller.

3. A wear-resistant ceramic impeller according to claim 2, wherein the pre-sintered ceramic block (201) is of silicon carbide or silicon nitride; the front cover plate (100) and the rear cover plate (300) are both made of silicon nitride combined silicon carbide materials or oxide combined silicon carbide materials.

4. The wear-resistant ceramic impeller of claim 2, wherein the pre-sintered ceramic block (201) is provided with an anti-falling protrusion (2011) on the outer side of the embedded part, the inner wall of the cavity of the front cover plate (100) or/and the rear cover plate (300) is provided with a groove, and the groove on the inner wall of the cavity is wrapped on the outer side of the anti-falling protrusion (2011) of the embedded part.

5. A wear resistant ceramic impeller according to claim 4, characterized in that the pre-sintered ceramic block (201) is dip coated with adhesive on the front cover plate (100) and the back cover plate (300).

6. A wear resistant ceramic impeller according to any one of claims 1 to 5, characterized in that at least two pre-sintered ceramic blocks (201) are provided at the working face of each blade (200), the back side of the pre-sintered ceramic blocks (201) being provided with blade attachment portions (202) supporting the pre-sintered ceramic blocks (201).

7. A wear-resistant ceramic impeller according to any one of claims 1 to 5, wherein the pre-sintered ceramic block (201) is provided with a connecting portion forming hole (204) arranged along the axial direction of the impeller, and the connecting portion forming hole (204) is filled with a blade connecting portion (202) integrally formed with the front cover plate (100) and the rear cover plate (300).

8. A method of manufacturing a wear resistant ceramic impeller in accordance with claim 1, the method comprising:

firstly, manufacturing a pre-sintered ceramic block (201), an impeller core box (400) and an impeller casting mold;

then, fixing the pre-sintered ceramic block (201) coated with the organic glue on the corresponding position of the impeller core box (400) and putting the pre-sintered ceramic block into an impeller casting mold;

then, pouring the prepared mixture into an impeller pouring mold, and after hardening, removing the mold and removing an impeller core box (400) to obtain an impeller blank embedded with the pre-sintered ceramic block (201);

then, ablating organic glue on the surface of the pre-sintered ceramic block (201) to form an air gap at the joint of the pre-sintered ceramic block (201) and the impeller blank, and sintering the impeller blank to obtain an impeller sintered product;

and finally, performing grease filling treatment on an air gap between the pre-sintered ceramic block (201) and the impeller body to obtain the hardened impeller.

9. The method of claim 8, wherein the step of greasing comprises: and (3) immersing the fired impeller product into resin, taking out after the resin is filled in an air gap between the pre-sintered ceramic block (201) and the impeller body, removing the redundant resin on the impeller, and hardening the resin dipped and coated on the impeller to obtain the hardened impeller.

10. A method of manufacturing a wear resistant ceramic impeller in accordance with claim 8 or 9, wherein the step of ablating the organic glue comprises: placing the impeller blank into a sintering furnace, heating to 300-500 ℃, and ablating organic glue coated on the surface of the pre-sintered ceramic block (201) to form an air gap at the joint of the pre-sintered ceramic block (201) and the impeller blank; the sintering step comprises: introducing high-purity nitrogen into the sintering furnace, heating to 1400-1500 ℃ and carrying out nitridation sintering; or heating to 1400-1500 deg.c in oxidizing environment for oxidizing sintering.

Technical Field

The invention relates to the field of production of rotary power pump equipment, in particular to a wear-resistant ceramic impeller and a manufacturing method thereof.

Background

In the industries of ore dressing, smelting and the like, a centrifugal pump is often used for conveying a certain abrasive solid-liquid two-phase flow, and a wear-resistant pump is often used. Common wear-resistant pumps are usually made of wear-resistant alloys such as Cr26 and Cr15Mo3 or wear-resistant materials such as rubber, and the pumps made of the wear-resistant alloys cannot meet the use requirements under many working conditions.

As is known, wear-resistant ceramics have much higher wear resistance than wear-resistant alloys, such as silicon carbide ceramics, silicon nitride ceramics, alumina ceramics, silicon nitride combined with silicon carbide ceramics, etc., and the wear resistance thereof is several times or even tens of times higher than that of wear-resistant alloys, so CN 202100535U, CN 205687817U, CN 107654414A, CN 108302043A, CN 202100546U, etc. disclose some technical solutions of ceramic impellers. In view of the current state of the art, the ceramic material from which the impeller is made is primarily alumina (Al)₂O₃) Silicon nitride (Si)₃N₄) Silicon carbide (SiC) and silicon nitride-bonded silicon carbide (SiC-Si)₃N₄) And the oxide is combined with the silicon carbide. The wear resistance of the alumina ceramic is poor, the large-scale production is difficult, and the wear-resistant pump is obviously limited in the field with requirements on the wear resistance and the large-scale production; silicon nitride ceramics have high cost due to process reasons, large-scale process difficulty and difficult application; the reaction sintered silicon carbide ceramic has excellent wear resistance and relatively low cost, but is difficult to be upsized and has high cost due to the process reason, so that the application of the reaction sintered silicon carbide ceramic is limited; the microstructure of silicon nitride-bonded silicon carbide and oxide-bonded silicon carbide is similar, and they include main phase silicon carbide particles and a bonding phase, wherein the bonding phase is network silicon nitride, and the bonding phase is network oxide or mixture thereof such as alumina, silica, calcium oxide, etc., and the silicon nitride-bonded silicon carbide or oxide-bonded silicon carbide has a certain number of particlesThe micro air holes are beneficial to not generating defects such as cracking and the like during sintering, and also beneficial to absorbing impact energy during running of the impeller, and improving the impact resistance of the impeller. Therefore, the two materials are developed rapidly in the field of wear-resistant pumps in recent years, the manufacturing cost is lower in the materials, the wear resistance is better, and the two materials can be used for manufacturing impellers with larger sizes at present. Fig. 12 and 13 are schematic views of a prior art silicon nitride bonded silicon carbide or oxide bonded silicon carbide impeller comprising a front shroud 100 ', a back shroud 300 ', and a blade 200 ' of silicon nitride bonded silicon carbide or oxide bonded silicon carbide material, wherein the weight ratio of silicon carbide is about 70-75%, and the weight ratio of silicon nitride or oxide is about 25-30%. The manufacturing process of the silicon nitride combined silicon carbide comprises the steps of uniformly mixing 70-75 wt% of silicon carbide particles, 15-25 wt% of silicon powder and a bonding agent, molding, drying, heating in a nitriding furnace, introducing 99.99% of high-purity nitrogen, reacting the silicon powder and the nitrogen at about 1430 ℃ to generate silicon nitride, and obtaining a silicon nitride combined silicon carbide product after the reaction is finished; the silicon oxide-silicon carbide is prepared by mixing silicon carbide particles 70-75 wt%, silicon powder 15-25 wt%, alumina 5-15 wt%, calcium oxide and other oxides and binder uniformly, molding, drying, sintering in a sintering furnace, and reacting at 1430 deg.C with oxygen to obtain silicon oxide. Because the silicon nitride or oxide generated by the reaction completely covers the silicon carbide particles in a network shape and has certain strength and wear resistance, the wear resistance of the impeller made of the silicon nitride combined with the silicon carbide material or the silicon carbide combined with the oxide is greatly improved compared with that of a wear-resistant alloy impeller.

However, silicon nitride bonded silicon carbide or oxide bonded silicon carbide impellers also have some problems in application: one is that the impeller is a biphase material combined by a main phase silicon carbide and a binding phase material, wherein the wear resistance of the main phase silicon carbide is obviously higher than that of the binding phase, so that in use, the surface of the impeller is dimpled due to different wear rates of the two materials, the surface roughness of the impeller is higher, the efficiency is reduced, more importantly, when the roughness of the surface of the blade is higher, the cavitation resistance of the pump is obviously reduced, and the performance of the pump is greatly influenced. Secondly, when there are bigger particles in the medium, the abrasion speed of the head and the working face of the vane is much higher than that of other parts, and the severe abrasion of the head and the working face of the vane further deteriorates the cavitation resistance of the pump, and reduces the performance of the pump.

CN 209041168U discloses an impeller, in which a wear-resistant block is disposed in the middle of the impeller to improve the wear resistance of the blade and the cavitation resistance of the impeller, but this solution can only improve the wear resistance of the blade head, and has limited effect, and the wear-resistant block has a complex shape and higher cost.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art, and aims to provide a wear-resistant ceramic impeller which has better wear resistance, better cavitation resistance, proper cost and easy large-scale production.

The invention also aims to provide a manufacturing method of the wear-resistant ceramic impeller.

In order to achieve the first purpose, the invention provides a wear-resistant ceramic impeller, which comprises a front cover plate, a rear cover plate and a blade, wherein the blade comprises a pre-sintered ceramic block embedded in the front cover plate or/and the rear cover plate; the pre-sintered ceramic block is provided with an embedded part, the front cover plate or/and the rear cover plate is/are provided with a concave cavity embedded with the embedded part of the pre-sintered ceramic block, and the embedded part and the concave cavity are matched in outline.

Furthermore, the blade also comprises a blade connecting part which is formed by sintering the front cover plate and the rear cover plate at one time and is arranged between the front cover plate and the rear cover plate, and the blade connecting part is adapted to the back side surface of the pre-sintered ceramic block; the pre-sintered ceramic block is embedded into the front cover plate or/and the rear cover plate along the axial direction of the impeller.

Furthermore, the pre-sintered ceramic block is made of silicon carbide or silicon nitride; the front cover plate and the rear cover plate are both made of silicon nitride combined silicon carbide or oxide combined silicon carbide.

As a further improvement, the outer side of the embedded part of the pre-sintered ceramic block is provided with an anti-falling bulge, the inner wall of the cavity of the front cover plate or/and the rear cover plate is provided with a groove, and the groove of the inner wall of the cavity is wrapped on the outer side of the anti-falling bulge of the embedded part.

Furthermore, the joint of the pre-sintered ceramic block and the front cover plate or/and the rear cover plate is coated with adhesive in a dip mode.

As a further improvement, at least two pre-sintered ceramic blocks are arranged at the working face of each blade, and the back sides of the pre-sintered ceramic blocks are provided with blade connecting parts for supporting the pre-sintered ceramic blocks.

As a further improvement, the pre-sintered ceramic block is provided with a connecting part forming hole arranged along the axial direction of the impeller, and the connecting part forming hole is filled with a blade connecting part integrally formed with the front cover plate and the rear cover plate.

In order to achieve the second purpose, the invention also provides a manufacturing method of the wear-resistant ceramic impeller, which comprises the following steps:

firstly, manufacturing a pre-sintered ceramic block, an impeller core box and an impeller casting mold;

then, fixing the pre-sintered ceramic block coated with the organic glue on the corresponding position of the impeller core box and loading the pre-sintered ceramic block into an impeller casting mold;

then, pouring the prepared mixture into an impeller pouring mold, removing the mold and removing an impeller core box after hardening to obtain an impeller blank embedded with the pre-sintered ceramic blocks;

then, the organic glue on the surface of the pre-sintered ceramic block is ablated, so that an air gap is formed at the joint of the pre-sintered ceramic block and the impeller blank, and the impeller blank is sintered to obtain an impeller sintered product;

and finally, performing grease filling treatment on the air gap between the pre-sintered ceramic block and the impeller body to obtain the hardened impeller.

Further, the method for the filling treatment comprises the following steps: and (3) immersing the fired impeller product into resin, taking out the fired impeller product after the resin is filled in an air gap between the pre-sintered ceramic block and the impeller body, removing the redundant resin on the impeller, and hardening the resin dipped and coated on the impeller to obtain the hardened impeller.

Further, the organic glue ablation and nitridation sintering steps comprise: placing the impeller blank into a sintering furnace, heating to 300-500 ℃, and ablating organic glue coated on the surface of the pre-sintered ceramic block to form an air gap at the joint of the pre-sintered ceramic block and the impeller blank; the sintering step comprises: introducing high-purity nitrogen into the sintering furnace, heating to 1400-1500 ℃ and carrying out nitridation sintering; or heating to 1400-1500 deg.c in oxidizing environment for oxidizing sintering.

Advantageous effects

Compared with the prior art, the wear-resistant ceramic impeller and the manufacturing method thereof have the following beneficial effects:

(1) the body material of the impeller is silicon nitride combined with silicon carbide or oxide combined with silicon carbide, so that the large-scale impeller is easy to realize, and the cost is low; because the presintered ceramic block has relatively small overall dimension and simple shape, the process is easy to realize by adopting silicon carbide or silicon nitride materials, and the cost is relatively low;

(2) the pre-sintered ceramic block is made of a single-phase ceramic material, such as reaction sintered silicon carbide, pressureless sintered silicon carbide, hot pressed sintered silicon nitride and the like, the abrasion of the blade in the use process is uniform relative to the abrasion of silicon nitride combined silicon carbide or oxide combined silicon carbide made of a double-phase material, and the surface roughness is not obviously increased due to uneven abrasion, so that the cavitation resistance of the impeller can be prevented from being deteriorated;

(3) the presintered ceramic block adopts reaction sintered silicon carbide or hot-pressed sintered silicon nitride, and the material has self-lubricating property under the abrasion working condition, so that the abrasion of the material can be reduced, and the material can become smoother and smoother through abrasion, thereby being beneficial to improving the service life of a blade and the efficiency of an impeller and improving the cavitation resistance of a pump;

(4) the expansion coefficient of the pre-sintered ceramic block is close to that of silicon nitride combined silicon carbide or oxide combined silicon carbide, and the impeller blank or the pre-sintered ceramic block can be prevented from cracking in the sintering or cooling process due to thermal expansion by taking proper measures;

(5) reaction sintering silicon carbide, pressureless sintering silicon carbide or hot pressing sintering silicon nitride with better wear resistance is adopted at the head part of the blade with serious wear, so that the wear speed of the parts can be remarkably slowed down, and the service life of the impeller is remarkably prolonged;

(6) the presintered ceramic blocks with better wear resistance and smoother surface are arranged on the working surface of the blade, which is not only beneficial to improving the service life of the impeller, but also beneficial to improving the cavitation resistance of the impeller and improving the efficiency of the pump;

(7) during the casting process, a concave cavity matched with the contour of the embedded part of the pre-sintered ceramic block can be naturally formed at the part of the impeller blank combined with the pre-sintered ceramic block, so that the impeller blank and the pre-sintered ceramic block can be completely matched at the embedded part, and the pre-sintered ceramic block is favorably fixed;

(8) the pre-sintered ceramic block extends into the front cover plate or the rear cover plate along the axial direction of the impeller, so that the pre-sintered ceramic block is firmly fixed;

(9) the part of the pre-sintered ceramic block extending into the front cover plate or the rear cover plate along the axial direction of the impeller is provided with a bulge for preventing the blade from falling off, which is beneficial to improving the strength of the impeller;

(10) before the silicon nitride combined silicon carbide or oxide combined silicon carbide mixture is poured, organic glue with proper thickness (generally 0.2-0.5mm) is coated on the pre-sintered ceramic block, so that the organic glue can be burnt and damaged to be gas to escape at the temperature of about 300 ℃ plus 500 ℃, and a proper air gap is formed between the pre-sintered ceramic block and the impeller blank, and the pre-sintered ceramic block and the impeller blank can be prevented from cracking due to the difference of thermal expansion coefficients in the high-temperature sintering process;

(11) the sintered impeller embedded with the pre-sintered ceramic block is coated with the adhesive in a dipping way, so that the original air gap between the pre-sintered ceramic block and the impeller body can be filled, and the pre-sintered ceramic block and the impeller body are firmly combined together.

Drawings

FIG. 1 is a sectional view of example 1 of the present invention;

FIG. 2 is a cross-sectional view taken along A-A of FIG. 1;

FIG. 3 is a schematic view of the assembly of a pre-sintered ceramic block 201 in a core box according to example 1 of the present invention;

FIG. 4 is a sectional view of example 2 of the present invention;

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 4;

FIG. 6 is a schematic view of the assembly of a pre-sintered ceramic block 201 in a core box according to example 2 of the present invention;

FIG. 7 is a sectional view of example 3 of the present invention;

FIG. 8 is a cross-sectional view in the direction C-C of FIG. 7;

FIG. 9 is a schematic view of the assembly of pre-sintered ceramic blocks 201 in a core box according to example 3 of the present invention;

FIG. 10 is a sectional view of example 4 of the present invention;

FIG. 11 is a cross-sectional view taken along line D-D of FIG. 10;

FIG. 12 is a cross-sectional view of a prior art ceramic impeller;

fig. 13 is a cross-sectional view at E-E of fig. 12.

In the figure: 100. a front cover plate; 200. a blade; 201. pre-sintering the ceramic block; 202. a blade connecting portion; 2011. the anti-drop bulge; 204. a connecting part forming hole; 300. a rear cover plate; 400. an impeller core box.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

The specific embodiments of the present invention are such that:

example 1

As shown in fig. 1-3, a wear-resistant ceramic impeller, the body material of which is silicon nitride combined with silicon carbide, is not only easy to enlarge the impeller but also low in cost, and comprises a front cover plate 100, a rear cover plate 300 and a blade 200, wherein the blade 200 comprises a pre-sintered ceramic block 201 embedded in the front cover plate 100 or/and the rear cover plate 300. The pre-sintered ceramic block 201 is provided with an embedded part, the front cover plate 100 or/and the rear cover plate 300 is/are provided with a concave cavity embedded with the embedded part of the pre-sintered ceramic block 201, and the embedded part and the concave cavity are matched in outline. The pre-sintered ceramic block 201 is a ceramic wafer which is sintered when the impeller is molded; because the overall dimension of the pre-sintered ceramic block 201 is relatively small, the pre-sintered ceramic block is easy to be realized in the process by adopting the silicon carbide or silicon nitride material, and the cost is relatively low. Moreover, the pre-sintered ceramic block 201 is embedded into the front cover plate 100 and the rear cover plate 300, and is tightly connected with the front cover plate 100 and the rear cover plate 300, so that the structure is firmer and is not easy to loose. The front side surface of the pre-sintered ceramic block 201 is used as the working surface of the blade 200, the structural surface of the pre-sintered ceramic block 201 is smooth and has good wear resistance, and when the pre-sintered ceramic block is used, the wear is less, and the accumulation of solids in a pump is prevented, so that the blockage is prevented.

In the present embodiment, the vane 200 further includes a vane connecting portion 202 formed by one-time sintering and disposed between the front cover plate 100 and the rear cover plate 300, and the vane connecting portion 202 is adapted to the back side of the pre-sintered ceramic block 201; the pre-sintered ceramic block 201 is embedded into the front cover plate 100 or/and the rear cover plate 300 along the axial direction of the impeller; the presintering ceramic block 201 is arranged on the working surface of the blade 200, the front side surface of the presintering ceramic block 201 is the working surface, and the blade connecting part 202 is a supporting structure capable of supporting the front cover plate 100, the rear cover plate 300 and positioning the presintering ceramic block 201, so that the presintering ceramic block 201 is not easy to damage.

Cavities are provided in the front cover plate 100 and/or the back cover plate 300 to conform to the contour of the embedded portions of the pre-sintered ceramic blocks 201. The concave cavity profile is formed naturally at the joint of the impeller blank and the pre-sintered ceramic block 201 during casting molding, so that the two parts can be completely matched at the joint, and the pre-sintered ceramic block 201 is fixed.

In this embodiment, the pre-sintered ceramic block 201 is of silicon carbide or silicon nitride construction. The pre-sintered ceramic block 201 is made of a single-phase ceramic material, such as reaction sintered silicon carbide, pressureless sintered silicon carbide, hot pressed sintered silicon nitride and the like, the abrasion of the blade in the use process is uniform relative to the abrasion of silicon nitride and silicon carbide which are made of a double-phase material, and the surface roughness is not obviously increased due to uneven abrasion, so that the cavitation resistance of the impeller can be prevented from being deteriorated.

If the pre-sintered ceramic block 201 is made of reaction sintered silicon carbide or hot pressed sintered silicon nitride, the material has self-lubricating property under the abrasion working condition, so that the abrasion of the material can be reduced, and the material can become smoother through abrasion, thereby being beneficial to prolonging the service life of a blade and the efficiency of an impeller and improving the cavitation resistance of a pump. The pre-sintered ceramic block 201 is made of silicon carbide or silicon nitride, and the expansion coefficient of the pre-sintered ceramic block is close to that of silicon nitride combined with silicon carbide, so that the impeller blank or the pre-sintered ceramic block 201 can be prevented from cracking in the sintering or cooling process due to thermal expansion by taking proper measures. The reaction sintering silicon carbide, pressureless sintering silicon carbide or hot pressing sintering silicon nitride with better wear resistance is adopted at the head part of the blade with serious wear, so that the wear speed of the parts can be obviously slowed down, and the service life of the impeller is obviously prolonged.

In this embodiment, the outer side of the embedded portion of the pre-sintered ceramic block 201 is provided with an anti-falling protrusion 2011, the inner wall of the cavity of the front cover plate 100 or/and the rear cover plate 300 is provided with a groove, and the groove of the inner wall of the cavity is wrapped on the outer side of the anti-falling protrusion 2011 of the embedded portion. The anti-drop protrusion 2011 can prevent the pre-sintered ceramic block 201 from dropping, and is beneficial to improving the strength of the impeller. The cross-sectional width dimension of the anti-slip protrusions 2011 is greater than the cross-sectional width dimension of the pre-sintered ceramic block 201. The joint of the pre-sintered ceramic block 201 and the front cover plate 100 and the back cover plate 300 is coated with adhesive.

A method of manufacturing a wear resistant ceramic impeller, the method comprising:

firstly, manufacturing a pre-sintered ceramic block 201, an impeller core box 400 and an impeller casting mold;

then, fixing the pre-sintered ceramic block 201 coated with the organic glue on the corresponding position of the impeller core box 400 and loading the pre-sintered ceramic block into an impeller casting mold;

then, pouring the prepared mixture into an impeller pouring mold, and after hardening, removing the mold and removing an impeller core box 400 to obtain an impeller blank embedded with the pre-sintered ceramic block 201;

then, nitriding and sintering the impeller blank to obtain an impeller fired product;

and finally, performing grease filling treatment on the air gap between the pre-sintered ceramic block 201 and the impeller body to obtain the hardened impeller.

As shown in fig. 3, in the present embodiment, when the impeller is formed, the pre-sintered ceramic block 201 is fixed in the impeller core box 400, corresponding positions of the pre-sintered ceramic block 201 and the impeller core box 400 are matched, the pre-sintered ceramic block 201 is fixed in the corresponding position of the core box 400 by using the adhesive, the impeller core box 400 can adopt the lost foam, the impeller core box 400 fixed with the pre-sintered ceramic block 201 is placed in a mold, a mixture of silicon carbide particles, metal silicon powder and a binder is poured into the mold, the mold is removed after the mixture is hardened, the impeller core box 400 with the lost foam structure is heated and melted after being dried, so as to obtain a blank of the impeller, the blank is placed in a sintering furnace for nitridation sintering, silicon nitride generated by reaction of the metal silicon powder and nitrogen gas can coat the surface of the silicon carbide particles, so as to form an impeller body with higher mechanical strength, resin is dip-coated at a joint part, after the resin, the pre-sintered ceramic block 201 can be reliably fixed to the impeller.

The purpose of applying an organic glue with a proper thickness (generally 0.2-0.5mm) on the pre-sintered ceramic block 201 before casting is that the organic glue will be burned out and become gas to escape when the temperature is about 300-.

The method for the fat filling treatment comprises the following steps: and immersing the fired impeller product into resin, taking out after the resin fills the air gap between the pre-sintered ceramic block 201 and the impeller body, removing the redundant resin on the impeller, and hardening the resin dipped and coated on the impeller to obtain the hardened impeller. The sintered impeller embedded with the pre-sintered ceramic block 201 is coated with the adhesive, so that the original air gap between the pre-sintered ceramic block 201 and the impeller body can be filled, and the pre-sintered ceramic block 201 and the impeller body are firmly combined together.

The pre-sintered ceramic block 201 is provided with an anti-falling protrusion 2011 which can be axially embedded into the front cover plate 100 and the rear cover plate 300, and the impeller core box 400 is provided with a die cavity which is matched with the anti-falling protrusion 2011.

The method of removing the impeller core box 400 comprises: and arranging the impeller core box 400 with a lost foam structure, pouring the mixture into an impeller pouring mold, hardening, removing the mold, drying the blank, and heating to remove the impeller core box 400.

The mixture comprises silicon carbide particles, metal silicon powder and a binding agent. Silicon carbide particles, metal silicon powder and a binding agent are mixed into a uniform mixture according to a proportion, and the mixture is poured into an impeller pouring mold.

The organic glue ablation and nitridation sintering steps comprise: placing the impeller blank into a sintering furnace, heating to 300-500 ℃, and ablating organic glue coated on the surface of the pre-sintered ceramic block 201 to form an air gap at the joint of the pre-sintered ceramic block and the impeller blank; introducing high-purity nitrogen into the sintering furnace, and heating to 1400-1500 ℃ for nitridation sintering.

And (3) impregnating the sintered impeller with a bonding agent to fill the air gap at the bonding part of the pre-sintered ceramic sheet 201 with the bonding agent. And hardening the bonding agent to enable the impeller to be a firm whole to obtain the finished impeller.

Example 2

As shown in fig. 4 to 6, the present embodiment is substantially the same as embodiment 1, except that the front cover plate 100 and the rear cover plate 300 are made of oxide-bonded silicon carbide, the pre-sintered ceramic block 201 is a silicon nitride structure formed by thermal compression sintering, two pre-sintered ceramic blocks 201 are disposed on the working surface of the blade 200, blade connection portions 202 supporting the two pre-sintered ceramic blocks 201 are disposed on the back sides of the two pre-sintered ceramic blocks 201, and the two pre-sintered ceramic blocks 201 are in a sheet-like structure and are tightly attached to the blade connection portions 202. The part of the pre-sintered ceramic block 201 extending to the front cover plate 100 or the rear cover plate 300 in the axial direction of the impeller is provided with an anti-drop protrusion 2011 for preventing the pre-sintered ceramic block 201 from dropping out.

Example 3

The embodiment is substantially the same as embodiment 1, except that the pre-sintered ceramic block 201 is a pressureless sintered silicon carbide structure, a connecting part forming hole 204 arranged along the axial direction of the impeller is arranged on the pre-sintered ceramic block 201, the connecting part forming hole 204 is filled with a blade connecting part 202 integrally formed with the front cover plate 100 and the rear cover plate 300, the pre-sintered ceramic block 201 is a closed ring structure surrounding the blade connecting part 202, the contact area with the blade connecting part 202 is large, and the structure is firmer.

The impeller body is of a material structure combining silicon nitride and silicon carbide.

Example 4

As shown in fig. 10 and 11, this embodiment is substantially the same as embodiment 1, except that each vane 200 is composed of a pre-sintered ceramic block 201, that is, the material of the vane 200 is entirely silicon carbide ceramic or silicon nitride ceramic, so that the vane has very good wear resistance and cavitation resistance, and a drop-off prevention protrusion 2011 for preventing the pre-sintered ceramic block 201 from dropping off is provided at a position where the pre-sintered ceramic block 201 extends to the front cover plate 100 or the rear cover plate 300 along the axial direction of the vane.

The abrasion-resistant ceramic impeller is used for a bench test, and the flow of a cavitation point of the impeller is improved by about 17 percent compared with the flow of a cavitation point of the impeller in the prior art, namely the cavitation resistance of the impeller is greatly improved.

The wear-resistant ceramic impeller is used in a mine plant, and the comparison of the application results with the prior art shows that the wear speed of the head part of the blade is reduced by about 85 percent, so that the wear speed of the head part of the blade is lower than that of other parts of the impeller, and the service life of the impeller is greatly prolonged.

The above is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that several variations and modifications can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the utility of the patent.