阅读说明：本技术 一种陶瓷空心球/钛基复合泡沫材料及其离心铸造方法 (ceramic hollow sphere/titanium-based composite foam material and centrifugal casting method thereof ) 是由 杨倩倩 刘源 闫思洁 邵星海 马明星 曹磊 李一凡 白笑怡 潘红梅 鲁志敏 徐转 于 2019-09-10 设计创作，主要内容包括：本发明在钛金属现有的铸造设备和工艺基础上通过简单的改进提出一种陶瓷空心球/钛基复合泡沫材料的离心铸造方法,首先根据铸件产品的浇注系统制造离心铸造用铸型,而后在铸型内加入陶瓷空心球及用于将陶瓷空心球固定在铸型内铸件产品对应型腔内防止陶瓷空心球进入浇注系统的过滤网,而后将装有陶瓷空心球和过滤网的铸型进行预热后使用工装固定在离心盘上,放入真空炉中抽真空后,启动离心设备后进行钛或钛合金金属液的浇注,金属液凝固成形后去型清理得到陶瓷空心球/钛基复合泡沫材料,该复合泡沫材料兼具钛金属的质轻、高比强度、高防腐性能以及多孔金属的轻质、吸能、隔音、减震、电磁屏蔽功能,并且密度低,材料中的陶瓷球分布均匀。(The invention provides a centrifugal casting method of a ceramic hollow sphere/titanium-based composite foam material through simple improvement on the basis of the existing casting equipment and process of titanium metal, which comprises the steps of firstly manufacturing a casting mould for centrifugal casting according to a casting system of a casting product, then adding the ceramic hollow sphere and a filter screen for fixing the ceramic hollow sphere in a corresponding cavity of the casting product in the casting mould to prevent the ceramic hollow sphere from entering the casting system, then preheating the casting mould filled with the ceramic hollow sphere and the filter screen, fixing the casting mould on a centrifugal disc by using a tool, placing the casting mould in a vacuum furnace for vacuumizing, then starting centrifugal equipment, pouring titanium or titanium alloy molten metal, solidifying and forming the molten metal, removing the mould and cleaning to obtain the ceramic hollow sphere/titanium-based composite foam material, wherein the composite foam material has the light weight, high specific strength, high corrosion resistance and light weight of the porous metal, Energy absorption, sound insulation, shock absorption and electromagnetic shielding functions, and has low density and uniform distribution of ceramic balls in the material.)

1. A centrifugal casting method of a ceramic hollow sphere/titanium-based composite foam material is characterized by comprising the following steps:

[ step one ]: preparing and manufacturing a casting mold for centrifugal casting, wherein the casting mold is provided with a cavity, and the size of the cavity is set according to a casting product and a pouring system; at least one of the inside of a cavity corresponding to the casting product in the casting mold and the inside of a cavity corresponding to the gating system is provided with a filter screen placing groove;

[ step two ]: preparing ceramic hollow balls and a filter screen with the mesh number capable of preventing the ceramic hollow balls with the theoretically minimum grain size from passing through, and placing the casting mould, the ceramic hollow balls and the filter screen before assembly into degassing equipment for degassing;

[ step three ]: placing the ceramic hollow spheres into a cavity corresponding to a casting product in a casting mold, enabling the ceramic hollow spheres to be closely arranged, placing the filter screen into a filter screen placing groove for fixing the ceramic hollow spheres in the cavity corresponding to the casting product in the casting mold before metal liquid is poured, obtaining a set of casting mold with the ceramic hollow spheres and the filter screen, and then preheating the casting mold;

[ step four ]: placing the preheated casting mold on a centrifugal disc, fixing the casting mold by using a tool fixture, transferring the casting mold into a vacuum furnace for casting titanium metal, vacuumizing the interior of the vacuum furnace, and heating and melting the titanium or titanium alloy raw material;

[ step five ]: starting a centrifugal device to enable the casting mold to rotate around the central axis of the sprue, pouring molten titanium metal or titanium alloy metal into the casting mold, and enabling the metal to pass through gaps between the ceramic hollow spheres in the cavity under the action of centrifugal force to complete the mold filling process after sufficient seepage;

[ step six ]: and after the titanium metal liquid or the titanium alloy metal liquid is solidified and formed, closing the centrifugal device and the vacuumizing device, and removing the shape and cleaning to obtain the ceramic hollow sphere/titanium-based composite foam material.

2. The centrifugal casting method of the ceramic hollow sphere/titanium-based composite foam material according to claim 1, wherein the casting mold in the step one is one of a graphite mold and a precision casting mold shell, and the manufacturing method thereof is at least one of numerical control machining, 3D printing and mold manufacturing.

3. the centrifugal casting method of the ceramic hollow sphere/titanium-based composite foam material according to claim 1, wherein the material of the ceramic hollow sphere in the steps (II) and (III) is at least one of titanium carbide, boron carbide, silicon carbide, titanium nitride, silicon nitride, aluminum oxide and zirconium oxide, and the particle size of the material is 0.5-8 mm.

4. The centrifugal casting method of the ceramic hollow sphere/titanium-based composite foam material according to claim 1, wherein one or both of a high-temperature-resistant metal wire mesh and a non-metal filter screen are used as the filter screen in the steps (II) and (III).

5. the centrifugal casting method of ceramic hollow sphere/titanium-based composite foam material according to claim 1, wherein the preheating temperature in step three is 300-900 ℃.

6. The centrifugal casting method of ceramic hollow sphere/titanium-based composite foam material according to claim 1, wherein [ step four ] the titanium or titanium alloy raw material is heated and melted to 1800-1850 ℃.

7. A hollow ceramic sphere/titanium-based composite foam material prepared by the centrifugal casting method of any one of claims 1 to 6.

Technical Field

The invention belongs to the field of foam metal manufacturing, and particularly relates to a ceramic hollow sphere/titanium-based composite foam material and a centrifugal casting method thereof.

Background

the foam metal material has the excellent characteristics of low density, energy absorption, shock absorption, sound insulation, sound absorption and the like, and is always a hot point direction for the development and application of novel materials at home and abroad. The ceramic hollow ball is implanted into a metal matrix to manufacture a ceramic ball/metal matrix composite material, belonging to the new direction of foam metal preparation. Compared with the traditional foam metal, the ceramic ball/metal matrix composite material has higher relative density and improved mechanical property, and can be applied to manufacturing equipment such as aircraft carrier flight decks, light fast-assembly bridges, military vehicle anti-mine bottom plates, bulletproof composite armors, heavy equipment airborne buffer platforms, light missile launching well covers, train anti-collision structures, railway and highway sound insulation barriers, highway vibration isolation pads, safety school buses and the like.

There are generally four methods of producing foamed metal by casting processes at present: 1. adding a foaming agent and a tackifier into molten metal to obtain a preparation process of foamed metal; 2. blowing in the metal solution to obtain foam metal; 3. preparing porous metal by adopting a gas-liquid eutectic solidification Gasar process; 4. and adding the ceramic ball into the molten metal in the casting process to prepare the ceramic ball/metal matrix composite foam material. Because titanium has a high melting point, requires casting under vacuum, has active performance at high temperature, and can chemically react with a foaming agent, a thickening agent and foaming gas, the methods 1 and 2 cannot prepare porous titanium or need to be realized through a complex process. The Gasar process can prepare porous metals of copper, magnesium and alloys thereof, but the process requires gas to have high solubility in molten metal, and titanium does not have the characteristics, so that porous titanium cannot be prepared by the method 3. The following search patents all adopt the method 4 to prepare the ceramic ball/metal matrix composite foam material by different processes.

the invention patent with publication number CN109513906A provides a method for producing a hollow sphere metal composite foam material, which comprises the following steps: preparing a mould, wherein the mould is provided with a cavity, and the shape of the cavity is set according to the shape of a structural part to be prepared; preheating hollow ceramic balls, and filling the hollow ceramic balls into the cavity, wherein the hollow ceramic balls are closely arranged; heating and melting the metal raw material, and heating the metal melt to a casting temperature for later use; pouring the metal melt into the cavity, connecting the cavity with a negative pressure tank, pumping negative pressure, and infiltrating and filling the metal melt into gaps of the hollow ceramic balls under a negative pressure environment; and naturally cooling the metal melt, and demolding to obtain the hollow sphere metal composite foam material structural member. This method for producing porous titanium has the following disadvantages: the melting and casting processes of titanium are all in a vacuum state, gravity casting is directly carried out, the method can not realize the purpose of improving the infiltration speed of molten metal into the cavity through the negative pressure environment of the cavity, so that the problem that the infiltration depth is not high and even the infiltration cannot be carried out is caused, and the pouring environment and equipment mentioned by the method are greatly different from the environment and equipment used for casting titanium metal at present.

The invention patent with the publication number of 108486400A provides a metal-based hollow sphere composite foam material and a preparation method thereof. The composite foam material comprises a metal matrix and ceramic hollow spheres, wherein the ceramic hollow spheres are uniformly distributed in the metal matrix. The preparation method is simple to operate and low in cost, and the metal-based hollow sphere composite foam material is prepared by adding the ceramic hollow sphere into the metal liquid and stirring the ceramic hollow sphere and the metal liquid after solidification. The porous titanium prepared by the method has the following problems: the ceramic ball can be prepared by stirring under the condition that the relative density of the ceramic ball is close to that of molten metal, but the aim of light weight cannot be achieved, and if the density of the ceramic ball is low, the ceramic ball floats upwards in the molten metal, and a corresponding solution is not provided in the patent.

The invention patent with the publication number of CN104498759B provides a preparation method of a mixed hollow sphere metal-based light composite material, which is characterized in that a plurality of hollow sphere materials are mixed and added into a tackified alloy liquid, and the metal-based light composite material is prepared by electromagnetic stirring. The metal-based hollow sphere composite material prepared by the method has poor uniformity and high density due to various factors such as buoyancy, stirring and the like, and is difficult to prepare the light and uniform metal-based composite material.

The invention patent with the publication number of CN104588617B proposes a one-step method for preparing a metal-based lightweight composite material, which adopts a method that hollow spheres are poured into a casting mold for preheating, the ceramic spheres account for 2/3 of the volume of the casting mold, molten metal is poured from the upper part of the casting mold, and air is pumped from the lower part of the casting mold, and the method is used for manufacturing porous titanium and has the following defects: the hollow sphere is slowly preheated, the vacuumizing time is long, the infiltration speed is slow, the production efficiency is low, and the prepared composite material hollow sphere is low in volume fraction, high in material density and not suitable for engineering popularization and application.

The invention patent with the publication number of CN106435242A provides a metal-based ceramic composite material and a preparation method thereof, wherein the metal-based ceramic composite material is prepared by a vacuum infiltration flow method, hollow ceramic balls of the metal-based hollow ceramic ball composite material prepared by the method are distributed loosely, the occupied volume of the hollow ceramic balls is only 45% -55% of that of the composite material, the overall lightweight level of the composite material is poor, the infiltration of molten metal is ensured by the vacuum in a hollow ball accumulation casting mold, the accumulation mode of the hollow balls needs to be kept unchanged in the infiltration flow process, and the operation difficulty is high.

the invention patent with the publication number of CN103614586B provides Al₂O₃The preparation method of the hollow sphere/aluminum porous composite material adopts a 20-40 Mpa pressure seepage method to prepare the aluminum-based aluminum oxide hollow sphere composite foam, the problems of the method are similar to those of the production method of the hollow sphere metal composite foam material provided by the invention patent with the publication number of CN109513906A, besides, the hollow sphere needs to be made into a precast block, the process is complex, and the hollow ceramic sphere is easy to break under high pressure.

The invention patent with the publication number of CN103667849B provides a metal-based ceramic composite material and a manufacturing method and application thereof, wherein a solid ceramic ball composite material is prepared by a direct extrusion casting molding method, and the density of the composite material prepared by the method is high.

In conclusion, the existing ceramic ball/metal matrix composite material preparation technology cannot prepare the ceramic hollow ball/titanium matrix composite foam material with low density and uniform distribution, and has the problems of poor seepage effect, fragile ceramic ball, high density, high operation difficulty, difficulty in industrial popularization, incapability of effectively fixing the ceramic hollow ball and the like. The casting method of the existing metal titanium and titanium alloy mainly comprises two types of vacuum gravity casting and vacuum centrifugal casting, and has a great difference with the casting method in the existing ceramic ball/metal matrix composite material preparation technology, namely the low-density ceramic hollow ball/titanium matrix composite foam material can not be manufactured by improving the existing titanium casting production equipment and process. Therefore, a preparation process of the ceramic hollow sphere/titanium-based composite foam material, which is suitable for batch production and has low cost, is urgently needed, and a technical support is provided for popularization and application of the ceramic hollow sphere/titanium-based composite foam material.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a centrifugal casting method capable of manufacturing a ceramic hollow sphere/titanium-based composite foam material with low density and uniform distribution, and the mass production and personalized customization of the ceramic hollow sphere/titanium-based composite foam material can be realized by simple improvement on the basis of the existing casting equipment and process of titanium metal.

The purpose of the invention is realized by adopting the following technical scheme. The centrifugal casting method of the ceramic hollow sphere/titanium-based composite foam material provided by the invention comprises the following steps of:

[ step one ]: preparing and manufacturing a casting mold for centrifugal casting, wherein the casting mold is provided with a cavity, and the size of the cavity is set according to a casting product and a pouring system; at least one of the inside of a cavity corresponding to the casting product in the casting mold and the inside of a cavity corresponding to the gating system is provided with a filter screen placing groove;

[ step two ]: preparing ceramic hollow balls and a filter screen with the mesh number capable of preventing the ceramic hollow balls with the theoretically minimum grain size from passing through, and placing the casting mould, the ceramic hollow balls and the filter screen before assembly into degassing equipment for degassing;

[ step three ]: placing the ceramic hollow balls into a cavity corresponding to a casting product in a casting mold, and enabling the ceramic hollow balls to be tightly arranged; placing the filter screen in a filter screen placing groove for fixing the ceramic hollow ball in a cavity corresponding to a casting product in a casting mold before pouring molten metal to obtain a set of casting mold filled with the ceramic hollow ball and the filter screen, and then preheating the casting mold;

[ step four ]: placing the preheated casting mold on a centrifugal disc, fixing the casting mold by using a tool fixture, transferring the casting mold into a vacuum furnace for casting titanium metal, vacuumizing the interior of the vacuum furnace, and heating and melting the titanium or titanium alloy raw material;

[ step five ]: starting a centrifugal device to enable the casting mold to rotate around the central axis of the sprue, pouring molten titanium metal or titanium alloy metal into the casting mold, and enabling the metal to pass through gaps between the ceramic hollow spheres in the cavity under the action of centrifugal force to complete the mold filling process after sufficient seepage;

[ step six ]: and after the titanium metal liquid or the titanium alloy metal liquid is solidified and formed, closing the centrifugal device and the vacuumizing device, and removing the shape and cleaning to obtain the ceramic hollow sphere/titanium-based composite foam material.

Further, in the step one, the casting mold is one of a graphite mold and a precision casting mold, and the manufacturing method thereof is at least one of numerical control machining, 3D printing and mold manufacturing.

Further, the ceramic hollow spheres in the step two and the step three are made of at least one of titanium carbide, boron carbide, silicon carbide, titanium nitride, silicon nitride, aluminum oxide and zirconium oxide, and the particle size of the ceramic hollow spheres is 0.5-8 mm.

further, in the steps II and III, one or two of a high-temperature-resistant metal wire mesh and a non-metal filter screen are used as the filter screen.

Further, the preheating temperature in the third step is 300-900 ℃.

Further, step four, the titanium or titanium alloy raw material is heated and melted to 1800-1850 ℃.

the centrifugal casting method of the ceramic hollow sphere/titanium-based composite foam material has the following beneficial effects:

1. The process for preparing the ceramic hollow sphere/titanium-based composite foam material by adopting the centrifugal casting method is simple, the seepage of metal liquid among ceramic spheres can be realized on the basis of the existing centrifugal casting equipment and process for casting titanium, and the method has the advantages of good seepage effect, simple process flow, high production efficiency, low manufacturing cost and the like;

2. The preparation process can meet the requirements of manufacturing castings with different shapes, and is easy to realize batch production and personalized customization of products;

3. when the graphite mold is selected for the casting mold, not only mold separation is easy to realize, but also the placement position of the filter screen is easier to control, so that the distribution area of the ceramic hollow sphere/titanium-based composite foam material in the casting is controlled.

The ceramic hollow sphere/titanium-based composite foam material prepared by the centrifugal casting method has the following beneficial effects:

1. The prepared ceramic hollow sphere/titanium-based composite foam material has the light weight, high specific strength and high corrosion resistance of titanium metal, and the light weight, energy absorption, sound insulation, shock absorption and electromagnetic shielding functions of porous metal;

2. The prepared ceramic hollow sphere/titanium-based composite foam material has low density, and the titanium metal porous material with low density can be obtained under the condition that the ceramic spheres are completely filled. (ii) a

3. In the prepared ceramic hollow sphere/titanium-based composite foam material, the ceramic spheres are uniformly distributed, and stable production can be realized.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

drawings

FIG. 1 is a casting and gating system process design for a product of the present invention;

FIGS. 2A to 2C are graphite-type and graphite-type component designs of the product of FIG. 1;

Fig. 3 is a schematic diagram of the assembly process of the graphite type ceramic hollow sphere and the filter screen of the product in fig. 1.

fig. 4 is an enlarged schematic view at a in fig. 3.

[ reference numerals ]

1. Casting a product; 2. a pouring system; 3. molding; 4. molding; 5. a loose block; 6. a filter screen placing groove; 7. a filter screen; 8. ceramic hollow ball

Detailed Description

The following describes the specific structure, operation principle and operation process of the present invention in detail with reference to the accompanying drawings and embodiments.