阅读说明：本技术 一种致密构件的制备方法 (Preparation method of compact component ) 是由 宋凯强 李忠盛 吴护林 何庆兵 丛大龙 赵子鹏 张敏 张隆平 于 2018-09-13 设计创作，主要内容包括：本发明涉及一种致密构件的制备方法,它包括以下步骤：(A)制备喷涂构件；(B)制备预致密构件；(C)制备二次致密构件；(D)制备所需构件。它在预致密化处理过程中,利用石英玻璃在高温下软化流动的特点形成包套,即同时实现了包套的形成和构件的预致密化；在二次致密化处理过程中设置预留空间,使石英玻璃在高温下依靠重力脱落,同步实现构件的致密化与包套的去除,达到事半功倍的效果,且不受喷涂构件形状的影响,可用于任何形状的喷涂构件的制备,也不需单独将喷涂构件封进包套内,工艺简单,耗时少,减少资源的消耗,有助于推进等离子喷涂构件的工程应用。(The invention relates to a preparation method of a compact member, which comprises the following steps: (A) preparing a spraying component; (B) preparing a pre-compact member; (C) preparing a secondary compact component; (D) preparing the required member. In the process of pre-densification treatment, a sheath is formed by utilizing the characteristic that quartz glass softens and flows at high temperature, namely the formation of the sheath and the pre-densification of a component are realized simultaneously; the reserved space is arranged in the secondary densification treatment process, so that the quartz glass falls off by means of gravity at high temperature, the densification of the component and the removal of the sheath are synchronously realized, the effect of achieving twice the result with half the effort is achieved, the spraying component is not influenced by the shape of the spraying component, the method can be used for preparing the spraying component in any shape, the spraying component does not need to be separately sealed into the sheath, the process is simple, the consumed time is short, the consumption of resources is reduced, and the method is favorable for promoting the engineering application of the plasma spraying component.)

1. A method for preparing a dense component, comprising the steps of:

(A) spraying a coating material on the surface of the manufactured core mold by adopting a plasma spraying technology to obtain a spraying component; wherein the material of the core mold is selected from a graphite core mold; the shape of the core mould is a symmetrical shape or an asymmetrical shape; the symmetric shape includes: any one of cylindrical, conical, or laval, and the asymmetric shape comprises a trapezoid; the coating material comprises: single component materials or multi-component composites; preferably, the single component material comprises: mo or W, the multicomponent composite material comprises: Mo-La₂O₃W-Re, W-Ni-Fe or ZrO₂-any one of Mo; the thickness of the coating is 1-20 mm;

(B) performing pre-densification treatment on a spraying component mixed with quartz glass by adopting a hot isostatic pressing technology, specifically, putting the spraying component into a graphite crucible, then breaking broken quartz glass or massive quartz glass serving as a sheath material, filling the broken quartz glass or massive quartz glass into the graphite crucible filled with the spraying component, putting the graphite crucible into hot isostatic pressing equipment for pre-densification treatment, after the pre-densification process is completed, sawing the graphite crucible, taking out the spraying component coated with the quartz glass, slightly knocking out most of the quartz glass on the surface by using a hammer, and finally obtaining the pre-densification component completely coated with the quartz glass on the surface, wherein the hot isostatic pressing process conditions comprise that the sintering temperature is 1000 ℃ and 1400 ℃, the loading pressure is 10-100MPa, the pressure maintaining time is 1-4h, and the pressure medium comprises argon and/or nitrogen;

(C) performing secondary densification treatment on the pre-densified component with the bottom provided with a space for falling of the quartz glass by adopting a hot isostatic pressing technology to obtain a secondary densified component, wherein the hot isostatic pressing process conditions comprise that the sintering temperature is 1400-;

(D) finishing the secondary densified component obtained in the step (C) according to the structure and the size of the component required to be prepared, and removing the core mold to prepare the required component;

wherein the purity of the quartz glass is more than 95%.

2. The method for producing a dense member according to claim 1, wherein: the quartz glass comprises industrial quartz glass leftover materials; the coating thickness is preferably 1-15 mm.

3. A process for the preparation of a densified structure according to claim 1 or 2, wherein: in the step (B), the process conditions of hot isostatic pressing include: the sintering temperature is 1200-1400 ℃, the loading pressure is 20-80MPa, the pressure maintaining time is 1-2h, and the pressure medium comprises argon and/or nitrogen; in the step (C), the hot isostatic pressing process conditions include: the sintering temperature is 1500-1600 ℃, the loading pressure is 140-160MPa, the pressure maintaining time is 1-2h, and the pressure medium comprises argon and/or nitrogen.

4. A process for the preparation of a densified structure according to claim 1 or 2, wherein: the shape of the quartz glass is block, granular or sheet; the thickness of the coating layer is the total thickness of the coating layer, and is sprayed once or sprayed for multiple times.

5. A method for producing a dense member according to claim 3, wherein: the shape of the quartz glass is block, granular or sheet; the thickness of the coating layer is the total thickness of the coating layer, and is sprayed once or sprayed for multiple times.

6. A method for preparing a dense component, comprising the steps of:

(A) preparation of spray Member

Firstly, designing and processing graphite as a raw material to manufacture a cylindrical graphite core mold with a clamping section at the end part;

fixing the graphite core mold on a rotating tool, and spraying a Mo coating with the total thickness of 20mm on the surface of the cylindrical graphite core mold by adopting a plasma spraying technology to obtain a spraying component;

(B) preparation of Pre-densified Components

Putting the spraying component into a graphite crucible, then breaking industrial quartz glass leftover with the purity of 91 percent, and filling the graphite crucible with the spraying component;

secondly, placing the graphite crucible into hot isostatic pressing equipment, and performing pre-densification treatment on the spraying component; wherein the sintering temperature is 1200 ℃, the loading pressure is 20MPa, the pressure maintaining time is 1h, and the pressure medium is high-purity argon;

sawing the graphite crucible by a mechanical method, taking out the spraying component after the pre-densification treatment, and lightly knocking out most of quartz glass on the surface of the component by a hammer to obtain a pre-densification component with the surface completely coated with the quartz glass;

(C) preparation of Secondary dense Components

Placing the pre-compact component into a graphite crucible, filling a small graphite block at the bottom of the component, and performing secondary densification treatment on the pre-compact component by adopting a hot isostatic pressing technology to obtain a secondary compact component with a little quartz glass on the surface; wherein the sintering temperature is 1450 ℃, the loading pressure is 150MPa, the pressure maintaining time is 1h, and the pressure medium is high-purity argon;

(D) preparation of the required Components

And (3) performing finish machining on the secondary dense component according to the structure and the size of the component to be prepared, and mechanically removing the cylindrical graphite core mold.

Technical Field

The invention relates to a treatment technology of a plasma spraying component, in particular to a preparation method of a compact component.

Background

As a novel forming technology, plasma spraying has extremely high temperature (more than 10000 ℃) and can almost melt any material, so the method has unique advantages in the aspects of preparing refractory metal, ceramic components and the like. However, due to the deposition characteristics of plasma spraying, defects such as microscopic holes, gaps, cracks and the like inevitably exist in a deposition layer, and the density is low (generally less than 90%); in addition, the deposited layer particle layers are mainly engaged mechanically, so that the bonding strength is poor, and the further application of a spray-formed part is restricted. The hot isostatic pressing technology is an effective method for densification, but if the hot isostatic pressing technology is directly adopted to perform densification treatment on a plasma spraying forming part, because the deposited layer of the forming part has more pores, a better internal and external pressure difference is difficult to form, and an ideal densification effect cannot be achieved, a corresponding sheath needs to be designed.

The sheath is a necessary container in the hot isostatic pressing technology, and is equivalent to a closed forming die, thereby being beneficial to improving the density of a sprayed part. At present, the sheath is prepared by sealing and welding a spray-molded part in the sheath under a high-temperature and vacuum environment. The densification effect of the sheath obtained by the method is good, but the process is complex, the time consumption is high, the resource is wasted, and the method is difficult to prepare the special-shaped sheath, so that the further development of the plasma spraying forming process is restricted.

Disclosure of Invention

The invention aims to provide a preparation method of a compact member, which has the advantages of simple process, less time consumption, no influence of the shape of a spraying member, capability of being used for preparing the spraying member in any shape and capability of ensuring higher density of the spraying member.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for preparing a dense component, comprising the steps of:

(A) spraying a coating material on the surface of the manufactured core mold by adopting a plasma spraying technology to obtain a spraying component; the material of the core mold can be a graphite core mold with good performance and low cost; the shape of the core mould is a symmetrical shape or an asymmetrical shape; preferably, the symmetrical shape comprises: any one of cylindrical, conical, or laval, and the asymmetric shape comprises a trapezoid; the coating material comprises: single component materials or multi-component composites; preferably, the single component material comprises: mo or W, the multicomponent composite material comprises: Mo-La₂O₃W-Re, W-Ni-Fe or ZrO₂-any one of Mo; the thickness of the coating is 1-20 mm;

(B) performing pre-densification treatment on a spraying component mixed with quartz glass by adopting a hot isostatic pressing technology, specifically, putting the spraying component into a graphite crucible, then breaking broken quartz glass or massive quartz glass serving as a sheath material, filling the broken quartz glass or massive quartz glass into the graphite crucible filled with the spraying component, putting the graphite crucible into hot isostatic pressing equipment for pre-densification treatment, after the pre-densification process is completed, sawing the graphite crucible, taking out the spraying component coated with the quartz glass, slightly knocking out most of the quartz glass on the surface by using a hammer, and finally obtaining the pre-densification component completely coated with the quartz glass on the surface, wherein the hot isostatic pressing process conditions comprise that the sintering temperature is 1000 ℃ and 1400 ℃, the loading pressure is 10-100MPa, the pressure maintaining time is 1-4h, and the pressure medium comprises argon and/or nitrogen;

(C) performing secondary densification treatment on the pre-densified component with the bottom provided with a space for falling of the quartz glass by adopting a hot isostatic pressing technology to obtain a secondary densified component, wherein the hot isostatic pressing process conditions comprise that the sintering temperature is 1400-;

(D) finishing the secondary densified component obtained in the step (C) according to the structure and the size of the component required to be prepared, and removing the core mold to prepare the required component;

wherein the purity of the quartz glass is more than 95%.

More preferably, the silica glass includes industrial silica glass cullet.

As a further preference, the coating thickness is preferably from 1 to 15 mm.

As a further preference, in the step (B), the process conditions of hot isostatic pressing include: the sintering temperature is 1200-1400 ℃, the loading pressure is 20-80MPa, the dwell time is 1-2h, and the pressure medium comprises argon and/or nitrogen.

As a further preference, in the step (C), the process conditions of hot isostatic pressing include: the sintering temperature is 1500-1600 ℃, the loading pressure is 140-160MPa, the pressure maintaining time is 1-2h, and the pressure medium comprises argon and/or nitrogen.

More preferably, the quartz glass may be in the form of a block, a granule, a sheet, or the like.

As a further preference, the coating thickness is the total thickness of the coating, and may be a single spray or multiple sprays.

The invention has the following beneficial effects:

the invention provides a preparation method of a compact member, which has the advantages of simple process, less time consumption, no influence of the shape of a spraying member, capability of being used for preparing the spraying member in any shape and capability of ensuring higher density of the spraying member. Specifically, in the process of pre-densification treatment, a sheath is formed by utilizing the characteristic that quartz glass softens and flows at high temperature, namely the formation of the sheath and the pre-densification of a component are realized simultaneously; the reserved space is arranged in the secondary densification treatment process, so that the quartz glass falls off by means of gravity at high temperature, the densification of the component and the removal of the sheath are synchronously realized, the effect of achieving twice the result with half the effort is achieved, the spraying component is not influenced by the shape of the spraying component, the method can be used for preparing the spraying component in any shape, the spraying component does not need to be separately sealed into the sheath, the process is simple, the consumed time is short, the consumption of resources is reduced, and the method is favorable for promoting the engineering application of the plasma spraying component.

Drawings

FIG. 1 is a graphite crucible containing a spray member and crushed quartz glass obtained in the 1 st step in the step (B) of example 1 of the present invention;

FIG. 2 is a view showing a pre-densified member having a surface completely coated with quartz glass obtained in the 3 rd step in the step (B) of example 1 of the present invention;

FIG. 3 shows a secondary densified member having a small amount of silica glass remaining on the surface thereof obtained in step (C) of example 1 of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to specific examples, comparative examples and drawings, but those skilled in the art will understand that the following embodiments are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. Those who do not specify the conditions are performed according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

A preparation method of a compact member comprises the following steps:

(A) preparation of spray Member

1. Designing and processing a cylindrical graphite core mold with a clamping section at the end part by taking graphite as a raw material;

2. and fixing the graphite core mold on a rotating tool, and spraying a Mo coating with the total thickness of 20mm on the surface of the cylindrical graphite core mold by adopting a plasma spraying technology to obtain the spraying component.

(B) Preparation of Pre-densified Components

1. Putting the spraying component into a graphite crucible, then breaking industrial quartz glass leftover (with the purity of 91%) and filling the graphite crucible (shown in figure 1) filled with the spraying component;

2. and putting the graphite crucible into hot isostatic pressing equipment, and performing pre-densification treatment on the spraying component. Wherein the sintering temperature is 1200 ℃, the loading pressure is 20MPa, the pressure maintaining time is 1h, and the pressure medium is high-purity argon;

3. sawing the graphite crucible by a mechanical method, taking out the spraying component (coated quartz) after the pre-densification treatment, and lightly knocking out most of the quartz glass on the surface of the component by a hammer to obtain the pre-densification component (shown in figure 2) with the surface completely coated with the quartz glass.

(C) Preparation of Secondary dense Components

The pre-densified component was placed in a graphite crucible and a small graphite block was placed on the bottom of the component and the component was subjected to a secondary densification process using hot isostatic pressing to obtain a secondary densified component with a small amount of silica glass on the surface (shown in fig. 3). Wherein the sintering temperature is 1450 ℃, the loading pressure is 150MPa, the pressure maintaining time is 1h, and the pressure medium is high-purity argon.

(D) Preparation of the required Components

And (3) performing finish machining on the secondary dense component according to the structure and the size of the component to be prepared, and mechanically removing the cylindrical graphite core mold to obtain the required component, wherein the compactness of the component is 99%.

It should be noted that, the purity is an important index of quartz glass, and has a great influence on the physicochemical properties and the service performance, so for the present invention, if the quartz glass with the purity not higher than 90% is used as a sheath material, a compact quartz glass sheath cannot be formed due to more impurities, and a sample and hot isostatic pressing equipment are also polluted; even in the case of high-purity quartz glass (more than 90%), the degree of purity varies, and softening and fluidity exhibited at high temperatures vary, which also affects the degree of compaction of the member. In the process of secondary densification treatment, a reserved space is needed, for example, a small graphite block can be placed at the bottom of the pre-densification member to cushion the pre-densification member, and a space for quartz glass to fall is reserved; if the reserved space is not arranged, quartz glass can remain at the bottom of the secondary densification component, and the subsequent steps are prevented from being carried out. The surface of the secondary densified member still has a little quartz glass which has not fallen clean, but the subsequent steps have not been affected. The graphite core mold structurally comprises a main body mold and a clamping section, wherein the clamping section extends out of the end part of the main body mold and is coaxial with the main body mold, and the outline of the main body mold is used for preparing a spraying component.

Example 2

A preparation method of a compact member comprises the following steps:

(A) preparation of spray Member

1. Designing and processing graphite serving as a raw material to manufacture a Laval-shaped graphite core mold with a clamping section at the end part;

2. and fixing the graphite core mold on a rotating tool, and spraying a W coating with the total thickness of 8mm on the surface of the Laval-shaped graphite core mold by adopting a plasma spraying technology to obtain the spraying component.

(B) Preparation of Pre-densified Components

1. Putting the spraying component into a graphite crucible, then breaking industrial quartz glass leftover materials (with the purity of 99 percent), and filling the graphite crucible filled with the spraying component;

2. and putting the graphite crucible into hot isostatic pressing equipment, and performing pre-densification treatment on the spraying component. Wherein the sintering temperature is 1400 ℃, the loading pressure is 80MPa, the pressure maintaining time is 2h, and the pressure medium is high-purity argon;

3. sawing the graphite crucible by a mechanical method, taking out the spraying component (coated quartz) after the pre-densification treatment, and lightly knocking out most of quartz glass on the surface of the component by a hammer to obtain the pre-densification component with the surface completely coated with the quartz glass.

(C) Preparation of Secondary dense Components

And placing the pre-densified component into a graphite crucible, filling a small graphite block at the bottom of the component, and performing secondary densification treatment on the component by adopting a hot isostatic pressing technology to obtain a secondary densified component with a little quartz glass on the surface. Wherein the sintering temperature is 1600 ℃, the loading pressure is 160MPa, the pressure maintaining time is 2h, and the pressure medium is high-purity argon.

(D) Preparation of the required Components

And (3) performing finish machining on the secondary dense component according to the structure and the size of the component to be prepared, and mechanically removing the Laval graphite core mold to obtain the required component, wherein the compactness of the component is 98%.

Example 3

A preparation method of a compact member comprises the following steps:

(A) preparation of spray Member

1. Designing and processing a conical graphite core mold with a clamping section at the end part by taking graphite as a raw material;

2. and fixing the graphite core mold on a rotating tool, and spraying a W-Ni-Fe coating layer with the total thickness of 2mm on the surface of the conical graphite core mold by adopting a plasma spraying technology to obtain the spraying component.

(B) Preparation of Pre-densified Components

1. Putting the spraying component into a graphite crucible, then breaking industrial quartz glass leftover materials (with the purity of 93 percent), and filling the graphite crucible filled with the spraying component;

2. and putting the graphite crucible into hot isostatic pressing equipment, and performing pre-densification treatment on the spraying component. Wherein the sintering temperature is 1300 ℃, the loading pressure is 60MPa, the pressure maintaining time is 1.5h, and the pressure medium is high-purity argon;

3. sawing the graphite crucible by a mechanical method, taking out the spraying component (coated with quartz) after the pre-densification treatment, and lightly knocking out most of quartz glass on the surface of the component by a hammer to obtain the pre-densification component with the surface completely coated with the quartz glass.

(C) Preparation of Secondary dense Components

And placing the pre-densified component into a graphite crucible, filling a small graphite block at the bottom of the component, and performing secondary densification treatment on the component by adopting a hot isostatic pressing technology to obtain a secondary densified component with a little quartz glass on the surface. Wherein the sintering temperature is 1500 ℃, the loading pressure is 140MPa, the pressure maintaining time is 1h, and the pressure medium is high-purity argon.

(D) Preparation of the required Components

And (3) performing finish machining on the secondary dense component according to the structure and the size of the component to be prepared, and mechanically removing the conical graphite core mold to obtain the required component, wherein the compactness of the component is 99%.

Example 4

A preparation method of a compact member comprises the following steps:

(A) preparation of spray Member

1. Designing and processing a trapezoidal graphite core mold with a clamping section at the end part by taking graphite as a raw material;

2. and fixing the graphite core mold on a rotating tool, and spraying a W-Re coating with the total thickness of 1mm on the surface of the trapezoidal graphite core mold by adopting a plasma spraying technology to obtain a spraying component.

(B) Preparation of Pre-densified Components

1. Putting the spraying component into a graphite crucible, then breaking industrial quartz glass leftover materials (the purity is 95 percent), and filling the graphite crucible filled with the spraying component;

2. and putting the graphite crucible into hot isostatic pressing equipment, and performing pre-densification treatment on the spraying component. Wherein the sintering temperature is 1000 ℃, the loading pressure is 100MPa, the pressure maintaining time is 3h, and the pressure medium is high-purity nitrogen;

3. sawing the graphite crucible by a mechanical method, taking out the spraying component (coated quartz) after the pre-densification treatment, and lightly knocking out most of quartz glass on the surface of the component by a hammer to obtain the pre-densification component with the surface completely coated with the quartz glass.

(C) Preparation of Secondary dense Components

And placing the pre-densified component into a graphite crucible, filling a small graphite block at the bottom of the component, and performing secondary densification treatment on the component by adopting a hot isostatic pressing technology to obtain a secondary densified component with a little quartz glass on the surface. Wherein the sintering temperature is 1500 ℃, the loading pressure is 100MPa, the pressure maintaining time is 2h, and the pressure medium is high-purity nitrogen.

(D) Preparation of the required Components

And (3) performing finish machining on the secondary dense component according to the structure and the size of the component to be prepared, and mechanically removing the graphite core mold to obtain the required component, wherein the compactness of the component is 98%.

Example 5

A preparation method of a compact member comprises the following steps:

(A) preparation of spray Member

1. Designing and processing a cylindrical graphite core mold with a clamping section at the end part by taking graphite as a raw material;

2. fixing the graphite core mold on a rotary tool, and spraying Mo-La with a total thickness of 15mm on the surface of the cylindrical graphite core mold by adopting a plasma spraying technology₂O₃To obtain a sprayed member.

(B) Preparation of Pre-densified Components

1. Putting the spraying component into a graphite crucible, then breaking industrial quartz glass leftover materials (with the purity of 96 percent), and filling the graphite crucible filled with the spraying component;

2. and putting the graphite crucible into hot isostatic pressing equipment, and performing pre-densification treatment on the spraying component. Wherein the sintering temperature is 1100 ℃, the loading pressure is 10MPa, the pressure maintaining time is 4h, and the pressure medium is high-purity nitrogen;

3. sawing the graphite crucible by a mechanical method, taking out the spraying component (coated quartz) after the pre-densification treatment, and lightly knocking out most of quartz glass on the surface of the component by a hammer to obtain the pre-densification component with the surface completely coated with the quartz glass.

(C) Preparation of Secondary dense Components

And placing the pre-densified component into a graphite crucible, filling a small graphite block at the bottom of the component, and performing secondary densification treatment on the component by adopting a hot isostatic pressing technology to obtain a secondary densified component with a small amount of quartz glass on the surface. Wherein the sintering temperature is 1400 ℃, the loading pressure is 200MPa, the pressure maintaining time is 3h, and the pressure medium is high-purity nitrogen.

(D) Preparation of the required Components

And (3) performing finish machining on the secondary dense component according to the structure and the size of the component to be prepared, and mechanically removing the graphite core mold to obtain the required component, wherein the compactness of the component is 98%.

Example 6

A preparation method of a compact member comprises the following steps:

(A) preparation of spray Member

1. Designing and processing graphite serving as a raw material to manufacture a Laval-shaped graphite core mold with a clamping section at the end part;

2. fixing the graphite core mold on a rotary tool, and spraying ZrO with a total thickness of 12mm on the surface of the Laval graphite core mold by using a plasma spraying technology₂-coating of Mo, obtaining a sprayed member.

(B) Preparation of Pre-densified Components

1. Putting the spraying component into a graphite crucible, then breaking industrial quartz glass leftover materials (the purity is 97 percent), and filling the graphite crucible filled with the spraying component;

2. and putting the graphite crucible into hot isostatic pressing equipment, and performing pre-densification treatment on the spraying component. Wherein the sintering temperature is 1300 ℃, the loading pressure is 60MPa, the pressure maintaining time is 2h, and the pressure medium is high-purity nitrogen;

3. sawing the graphite crucible by a mechanical method, taking out the spraying component (coated quartz) after the pre-densification treatment, and lightly knocking out most of quartz glass on the surface of the component by a hammer to obtain the pre-densification component with the surface completely coated with the quartz glass.

(C) Preparation of Secondary dense Components

And placing the pre-densified component into a graphite crucible, padding a graphite block at the bottom of the component, and performing secondary densification treatment on the component by adopting a hot isostatic pressing technology to obtain a secondary densified component with a little quartz glass on the surface. Wherein the sintering temperature is 1500 ℃, the loading pressure is 150MPa, the pressure maintaining time is 1h, and the pressure medium is high-purity nitrogen.

(D) Preparation of the required Components

And (3) performing finish machining on the secondary dense member according to the structure and the size of the member to be prepared, and mechanically removing the graphite core mold to obtain the required member, wherein the compactness of the member is 96%.

Comparative example 1

Comparative example 1 provides a process for densifying a plasma sprayed article, the process being the same as that of example 1 except that step (D) is eliminated and step (C) is performed without a graphite block on the bottom of the article.

The experimental results of this comparative example 1 are: the prepared member cannot be taken out smoothly, and the preparation of the member cannot be realized.