阅读说明：本技术 一种硬质合金压制品烧结用隔层 (Interlayer for sintering hard alloy pressed product ) 是由 杨佳 林亮亮 邹伶俐 郑耀东 于 2020-11-13 设计创作，主要内容包括：本发明公开了一种硬质合金压制品烧结用隔层,隔层是制作在硬质合金压制品烧结用的承烧板上,以用来阻隔硬质合金压制品与承烧板的直接接触以及阻隔硬质合金压制品和承烧板在烧结过程中相互影响所产生的化学反应；隔层是由粒度范围在1um～150um的Al2O3、SiO2、TiO2、MgO、Cr2O3和ZrO2中的两种或两种以上氧化物组成,采用火焰喷涂技术,在0.10Mpa～0.40Mpa的乙炔、氧气作用下,成型在承烧板上。本发明的隔层不仅阻隔了硬质合金压制品和承烧板之间的物理化学反应,而且还尽可能的降低了隔层本身的物理化学变化,从而明显增加了隔层在硬质合金压制品烧结应用上的使用寿命。(The invention discloses an interlayer for sintering a hard alloy pressed product, which is manufactured on a burning bearing plate for sintering the hard alloy pressed product and is used for preventing the direct contact between the hard alloy pressed product and the burning bearing plate and preventing the chemical reaction generated by mutual influence between the hard alloy pressed product and the burning bearing plate in the sintering process; the interlayer is composed of two or more than two oxides of Al2O3, SiO2, TiO2, MgO, Cr2O3 and ZrO2 with the granularity range of 1-150 um, and is molded on the burning bearing plate by adopting a flame spraying technology under the action of acetylene and oxygen with the pressure of 0.10-0.40 Mpa. The interlayer provided by the invention not only blocks the physical and chemical reaction between the hard alloy pressed product and the burning bearing plate, but also reduces the physical and chemical changes of the interlayer as much as possible, thereby obviously prolonging the service life of the interlayer in the sintering application of the hard alloy pressed product.)

1. An interlayer for sintering a hard alloy pressed product is characterized in that: the interlayer is manufactured on the burning bearing plate for sintering the hard alloy pressed product and is used for preventing the direct contact between the hard alloy pressed product and the burning bearing plate and preventing the chemical reaction generated by the mutual influence between the hard alloy pressed product and the burning bearing plate in the sintering process; the interlayer is composed of two or more than two oxides of Al2O3 (aluminum oxide), SiO2 (silicon dioxide), TiO2 (titanium dioxide), MgO (magnesium oxide), Cr2O3 (chromium oxide) and ZrO2 (zirconium dioxide) with the granularity range of 1-150 um, and is formed on a burning bearing plate under the action of acetylene and oxygen with the pressure of 0.10-0.40 Mpa by adopting a flame spraying technology, so that the thickness of the interlayer is 50-500 um, and the porosity is 1-30%; wherein the molding temperature is 2500-3300 ℃.

2. The barrier for sintering of cemented carbide compacts as claimed in claim 1, wherein: the two or more oxides at least comprise Al2O3 (alumina), and the content of Al2O3 (alumina) accounts for more than 50 percent of the total weight of the two or more oxides.

3. The barrier for sintering of cemented carbide compacts as claimed in claim 2, wherein: further, the content of Al2O3 (alumina) is more than 60% of the total weight of the two or more oxides.

4. The spacer for sintering of cemented carbide compacts as claimed in claim 1, 2 or 3 wherein: the granularity of the two or more oxides is 10 um-100 um.

Technical Field

The invention belongs to the technical field of alloy materials, and particularly relates to an interlayer for sintering a hard alloy pressed product.

Background

The hard alloy is prepared by preparing powder of various carbides and bonding metals into a uniform mixture with a certain component and a certain particle size, and the mixture is pressed under pressure and then sintered into an alloy body. In the sintering process, a setter plate for a compact formed by pressing the mixture is supported. In the sintering process, the setter plate and the pressed product react to different degrees, the composition structure of the sintered alloy body is influenced, and the use performance of the alloy body is influenced, so that a sintering interlayer is required to be arranged between the setter plate and the pressed product.

The cost of the interlayer is relatively low without equipment investment in normal-temperature manual coating and graphite paper, the interlayer is found to have a short service life in tests, and a large number of cracks can appear after the interlayer is used for a plurality of times, so that the interlayer falls off and fails, and the interlayer is not beneficial to automation. While the research direction of manual coating is mainly focused on coating compositions, Chinese patent application CN104017396A, patent application CN1482193A, patent application CN107201061A and the like disclose different manual coating compositions, but the service life problem is not mentioned. For example, patent application CN1482193A discloses that carbon black, polyethylene glycol, tween, and anion water are mixed in a certain proportion to form a uniform suspension, and the uniform suspension is coated on a cemented carbide setter plate, so as to achieve the effects of no sticking to the boat during cemented carbide sintering, no surface contamination, permeation and decarburization phenomena, and ensure the dimensional accuracy and quality requirements of the product, but no relevant information is provided on the aspect of the service life of the suspension.

In the thermal spraying technology, the U.S. Pat. No. 8, 5993970 discloses an interlayer for cemented carbide sintering, which is realized by using a plasma spraying technology and a thermal spraying material mainly containing Y2O3 (yttrium oxide), and a Mo backing layer is pre-sprayed on a setter plate to increase the number of times of using the interlayer. Tests show that the service life of the interlayer taking Y2O3 as a main material is obviously prolonged, but after the product is sintered, the phenomenon that Y element overflows and adheres to the surface of the hard alloy is observed, and the appearance and the structure performance of the hard alloy are influenced.

The service life of the interlayer for sintering the hard alloy needs to consider the physical and chemical changes of the interlayer material in the molding and sintering processes and the thermal expansion coefficients of the interlayer material and the burning bearing plate. For example, during thermal spray barrier deposition, when molten spray particles move at high speed and collide with a setter plate, the particles cool rapidly from the melting temperature to the setter plate temperature or the temperature of the previous barrier, shrink rapidly, and cause non-uniformity in deformation, phase change, and state change of the material, resulting in residual stress. Meanwhile, in the deposition process of the thermal spraying interlayer, residual stress also exists when the thermal expansion coefficients of the spraying material and the burning bearing plate are different and the spraying material and the burning bearing plate are cooled to room temperature.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the interlayer for sintering the hard alloy pressed product, so that the interlayer not only blocks the physical and chemical reaction between the hard alloy pressed product and the burning bearing plate, but also reduces the physical and chemical changes of the interlayer as much as possible, thereby obviously prolonging the service life of the interlayer in the sintering application of the hard alloy pressed product.

The technical scheme adopted by the invention for solving the technical problems is as follows: an interlayer for sintering a hard alloy pressed product is manufactured on a burning bearing plate for sintering the hard alloy pressed product and is used for preventing the direct contact between the hard alloy pressed product and the burning bearing plate and preventing the chemical reaction generated by the mutual influence between the hard alloy pressed product and the burning bearing plate in the sintering process; the interlayer is composed of two or more than two oxides of Al2O3 (aluminum oxide), SiO2 (silicon dioxide), TiO2 (titanium dioxide), MgO (magnesium oxide), Cr2O3 (chromium oxide) and ZrO2 (zirconium dioxide) with the granularity range of 1-150 um, and is formed on a burning bearing plate under the action of acetylene and oxygen with the pressure of 0.10-0.40 Mpa by adopting a flame spraying technology, so that the thickness of the interlayer is 50-500 um, and the porosity is 1-30%; wherein the molding temperature is 2500-3300 ℃.

The two or more oxides at least comprise Al2O3 (alumina), and the content of Al2O3 (alumina) accounts for more than 50 percent of the total weight of the two or more oxides.

Further, the content of Al2O3 (alumina) is more than 60% of the total weight of the two or more oxides.

The granularity of the two or more oxides is 10 um-100 um.

The invention relates to an interlayer for sintering a hard alloy pressed product, which adopts a flame spraying technology to form the interlayer for sintering the hard alloy pressed product. Flame spraying means that a spray material (wire or powder) is melted by the high temperature of a gas combustion flame and sprayed onto the surface of a workpiece with a compressed air flow to form a coating. The flame spraying is that the metal and non-metal materials are heated to a molten state by using flame as a heat source, a fog flow is formed under the push of high-speed airflow and is sprayed on a substrate, and when the sprayed tiny molten particles impact on the substrate, plastic deformation is generated to form a sheet-shaped superposed deposition coating. The flame spraying is that fuel gas acetylene, propane, methyl acetylene-propadiene (MPS), hydrogen or natural gas and combustion-supporting gas oxygen are mixed and combusted to be used as a heat source, spraying materials enter flame in a certain transmission mode, are heated to a melting or softening state, and then are sprayed onto a substrate in an accelerating mode by means of the gas or the flame. Flame spraying is divided into wire flame spraying and powder flame spraying. The invention adopts powder flame spraying, which takes oxyacetylene flame as a heat source, sprays self-fluxing alloy powder on the surface of a pretreated workpiece, heats a coating to melt and wet the workpiece on the premise of ensuring that the workpiece is not melted, and forms a surface cladding layer which is in a metallurgical structure and has special performance by mutual dissolution and diffusion of liquid alloy and the surface of a solid workpiece.

Compared with the prior art, the invention has the beneficial effects that:

the interlayer of the invention selects two or more than two oxides of Al2O3 (aluminum oxide), SiO2 (silicon dioxide), TiO2 (titanium dioxide), MgO (magnesium oxide), Cr2O3 (chromium oxide) and ZrO2 (zirconium dioxide) which have thermal expansion coefficients similar to those of the setter plate, adopts flame spraying technology, and is formed on the setter plate under certain conditions, so that the difference between the interlayer forming temperature and the sintering use temperature can be reduced, and the physicochemical change of the interlayer during forming and sintering is avoided, so that the manufactured interlayer not only obstructs the physicochemical reaction between the hard alloy pressed product and the setter plate, but also reduces the physicochemical change of the interlayer itself as much as possible, thereby obviously prolonging the service life of the interlayer in the sintering application of the hard alloy pressed product.

The present invention will be described in further detail with reference to examples; however, the spacer for sintering a cemented carbide compact according to the present invention is not limited to the examples.

Detailed Description

Examples

The interlayer for sintering the hard alloy pressed product is manufactured on a burning bearing plate for sintering the hard alloy pressed product and is used for preventing the direct contact between the hard alloy pressed product and the burning bearing plate and preventing the chemical reaction generated by the mutual influence between the hard alloy pressed product and the burning bearing plate in the sintering process; the interlayer is composed of two or more than two oxides of Al2O3 (aluminum oxide), SiO2 (silicon dioxide), TiO2 (titanium dioxide), MgO (magnesium oxide), Cr2O3 (chromium oxide) and ZrO2 (zirconium dioxide) with the granularity range of 1-150 um, and is formed on a burning bearing plate under the action of acetylene and oxygen with the pressure of 0.10-0.40 Mpa by adopting a flame spraying technology, so that the thickness of the interlayer is 50-500 um, and the porosity is 1-30%; wherein the molding temperature is 2500-3300 ℃.

Cemented carbide is produced by powder metallurgy techniques by pressing to form a compact of cemented carbide having a particular geometry, the compact being sintered by placing it over the barrier of the present invention.

The interlayer of the invention adopts flame spraying technology, the gas pressure is controlled to be 0.10 Mpa-0.40 Mpa at the molding temperature of 2500-3300 ℃, and the interlayer is molded on the burning plate under the action of acetylene and oxygen. Flame spraying means that a spray material (wire or powder) is melted by the high temperature of a gas combustion flame and sprayed onto the surface of a workpiece with a compressed air flow to form a coating. The flame spraying is that the metal and non-metal materials are heated to a molten state by using flame as a heat source, a fog flow is formed under the push of high-speed airflow and is sprayed on a substrate, and when the sprayed tiny molten particles impact on the substrate, plastic deformation is generated to form a sheet-shaped superposed deposition coating. The flame spraying is that fuel gas acetylene, propane, methyl acetylene-propadiene (MPS), hydrogen or natural gas and combustion-supporting gas oxygen are mixed and combusted to be used as a heat source, spraying materials enter flame in a certain transmission mode, are heated to a melting or softening state, and then are sprayed onto a substrate in an accelerating mode by means of the gas or the flame. Flame spraying is divided into wire flame spraying and powder flame spraying. The invention adopts powder flame spraying, which takes oxyacetylene flame as a heat source, sprays self-fluxing alloy powder on the surface of a pretreated workpiece, heats a coating to melt and wet the workpiece on the premise of ensuring that the workpiece is not melted, and forms a surface cladding layer which is in a metallurgical structure and has special performance by mutual dissolution and diffusion of liquid alloy and the surface of a solid workpiece.

The thickness of the formed interlayer is measured at multiple points by a micrometer, the cross-sectional morphology of the interlayer is shot by a Hitachi S-3700N Scanning Electron Microscope (SEM), the porosity is counted by image processing software, and a mercury intrusion instrument is used for detecting through holes in the interlayer.

The present invention will be described in further detail with reference to specific examples.

Example 1

An interlayer for sintering a hard alloy compact, the blade model is CNMG120404, the compact is a hard alloy with ultrafine grain, the WC average grain diameter is 0.4um, wherein the Co mass percent is 12%.

1-5 of interlayer: the material of the interlayer is selected from A and not more than 50 wt.% B, wherein A is Al2O3, and B is one or more of SiO2, TiO2, MgO, Cr2O3 or ZrO 2.

6-12 of interlayer: the setter plates, blade type and pressed articles of the comparative interlayers were the same as in the present invention.

(1) Applying a plasma spraying technology to form a contrast barrier, wherein the barrier is made of ZrO2, Y2O3, Al2O3, SiO2 and Cr2O 3;

(2) by applying the invention, compared with the forming of the interlayer, the material of the interlayer is selected from Al2O3, Cr2O3, Y2O3, SiO2 and ZrO 2.

The molding information and the characteristic index of each interlayer are shown in table 1.

TABLE 1 interlayer formation information and characteristic index

And (3) placing the pressed product on different burning bearing plate interlayers, wherein the sintering temperature is 1380 ℃, sintering for 60min, cooling to the temperature below 1000 ℃ at the cooling rate of 10-100 ℃/min, naturally cooling, then unloading the alloy, placing the pressed product on the interlayers for secondary sintering, and repeatedly sintering and cooling until the burning bearing plate interlayers fail.

1-5 of interlayer: the service life of the interlayer is 15-25 times, the surface of the interlayer is complete in the early sintering process, and partial or integral falling or cracking does not occur. In the later sintering process, the interlayer finally loses efficacy due to local falling of the contact area, and sintered products can be easily dismounted in the whole sintering process, and the surface is not abnormal.

And (3) an interlayer 6: compared with the service life of the interlayer ZrO2+ 8% Y2O3, the interlayer is slightly bonded with a sintered product in the early sintering process, the local falling caused by bonding the bottom of the sintered sample in the contact area of the sintered sample and the interlayer is ineffective in the later sintering process, the sintered product needs to be dismounted with little force, and the interlayer material of the bonded part on the surface of the sintered sample is used.

7-8 of interlayer: compared with the interlayer Al2O3+ 25% SiO2 and Al2O3+ 30% Cr2O3, the plasma spraying technology is adopted, large cracks appear in the early sintering process, a small part of cracks fall off, and the large crack interlayer falls off completely in the later sintering process to cause failure.

9-12 of interlayer: compared with the service life of the interlayer of 3-10 times due to different materials, the Cr2O3 interlayer is peeled off due to a great amount of cracks generated in the sintering process. During the whole sintering process of the Al2O3 interlayer, cracks are gradually generated on the surface of the interlayer, and finally, the interlayer is largely peeled off and fails. During the later sintering process of the Al2O3+ 30% Y2O3 and ZrO2+ 25% SiO2 interlayer, a contact area between a sintered sample and the interlayer is failed due to local falling caused by bonding at the bottom of the sintered sample, and meanwhile, Y-element impurities with different degrees appear on the surface of the Al2O3+ 30% Y2O3 interlayer sintered sample.

And (3) separation layer 13: compared with the interlayer Al2O3+ 25% SiO2, the thickness of the interlayer is reduced, the local falling time of a sintered sample and an interlayer contact area is obviously advanced, and the interlayer of the contact area completely falls off and fails in the later sintering process.

The separation layer 14: compared with the porosity increase of the interlayer Al2O3+ 30% Cr2O3, the whole interlayer has slight crack in the early sintering process, and the whole interlayer has serious crack and falls off to fail in the later sintering process.

Example 2

The interlayer for sintering the hard alloy pressed product has a blade model of CNMG120404, the pressed product is a hard alloy with submicron particles, the average grain diameter of WC is 0.8um, and the mass percent of Co is 10%. The spacer material selection was the same as in example 1.

The molding information and the characteristic index of each interlayer are shown in table 2.

TABLE 2 interlayer formation information and characteristic index

And (3) placing the pressed product on different burning bearing plate interlayers, wherein the sintering temperature is 1420 ℃, sintering for 60min, cooling to below 1000 ℃ at a cooling rate of 10-100 ℃/min, naturally cooling, then unloading the alloy, placing the pressed product on the interlayers for secondary sintering, and repeatedly sintering and cooling until the burning bearing plate interlayers fail.

1-5 of interlayer: the service life of the interlayer is 18-26 times, the surface of the interlayer is complete in the early sintering process, and partial or whole falling or cracking does not occur. In the later sintering process, the interlayer finally loses efficacy due to local falling of the contact area, and sintered products can be easily dismounted in the whole sintering process, and the surface is not abnormal.

And (3) an interlayer 6: the service life of the comparison interlayer ZrO2+ 8% Y2O3 is 9 times, the interlayer slightly adheres to a sintered product in the early sintering process, the local falling caused by adhesion of the bottom of the sintered sample and the interlayer contact area fails in the later sintering process, the sintered product needs to be detached slightly and the interlayer material of the adhered part on the surface of the sintered sample needs to be detached slightly.

7-8 of interlayer: compared with the interlayers Al2O3+ 25% SiO2 and Al2O3+ 30% Cr2O3, the plasma spraying technology is adopted, partial cracking occurs in the early sintering process, a small part of cracking phenomenon occurs, and a large cracking interlayer completely falls off and fails in the later sintering process.

9-12 of interlayer: compared with the prior art that the service life of the Cr2O3 interlayer is 5-12 times due to different materials, the Cr2O3 interlayer has partial cracks and small parts of falling phenomena in the early sintering process, and a large amount of cracks are generated in the later sintering process to fall off. During the early sintering process of the Al2O3 interlayer, obvious cracking and bonding phenomena do not occur in the interlayer, and during the later sintering process, the surface of the interlayer gradually cracks, and finally the interlayer falls off in a large amount to fail. During the early sintering period of the Al2O3+ 30% Y2O3 and ZrO2+ 25% SiO2 interlayer, the interlayer slightly adheres to a sintered product, during the later sintering period, a contact area between a sintered sample and the interlayer is partially fallen off due to adhesion at the bottom of the sintered sample to cause failure, and meanwhile, impurities of Y elements with different degrees appear on the surface of the Al2O3+ 30% Y2O3 interlayer sintered sample.

And (3) separation layer 13: compared with the interlayer Al2O3+ 25% SiO2, the thickness of the interlayer becomes thinner, the adhesion phenomenon of a sintered sample and an interlayer contact area occurs, and in the later sintering process, the interlayer of the contact area completely falls off and fails.

The separation layer 14: compared with the porosity increase of the interlayer Al2O3+ 30% Cr2O3, the middle separation layer has slight cracking in the early sintering process, and the whole interlayer has serious cracking and falling off in the later sintering process to fail.

Example 3

The interlayer for sintering the hard alloy compact has the blade model of CNMG120404, the compact is medium-particle hard alloy, the average WC grain diameter is 1.5um, and the mass percent of Co is 6 percent. The spacer material selection was the same as in example 1.

The molding information and the characteristic index of each interlayer are shown in Table 3.

TABLE 3 interlayer formation information and characteristic index

And (3) placing the pressed product on different burning bearing plate interlayers, wherein the sintering temperature is 1450 ℃, sintering for 60min, cooling to the temperature below 1000 ℃ at the cooling rate of 10-100 ℃/min, then naturally cooling, then unloading the alloy, placing the pressed product on the interlayers for secondary sintering, and repeatedly sintering and cooling until the burning bearing plate interlayers fail.

1-5 of interlayer: the service life of the interlayer is 20-30 times, and in the early sintering process, the surface of the interlayer is complete and no local or overall shedding or cracking occurs. In the later sintering process, the interlayer finally loses efficacy due to local falling of the contact area, and sintered products can be easily dismounted in the whole sintering process, and the surface is not abnormal.

And (3) an interlayer 6: compared with the service life of the interlayer ZrO2+ 8% Y2O3, the service life of the interlayer ZrO2+ 8% Y2O3 is 12 times, the surface of the interlayer is complete in the early sintering process, the phenomenon of slight bonding with a sintered product does not occur, in the later sintering process, the sintered sample and the interlayer contact area lose effectiveness due to local falling caused by bonding at the bottom of the sintered sample, the sintered product needs to be dismounted slightly by force, and the interlayer material of the bonding part on the surface of the sintered sample is used as the interlayer material.

7-8 of interlayer: compared with the interlayer Al2O3+ 25% SiO2 and Al2O3+ 30% Cr2O3, the plasma spraying technology is adopted, partial cracking occurs in the early sintering process, but the phenomenon of falling does not occur, in the later sintering process, the cracking condition is serious, and partial interlayer fails due to the cracking and falling.

9-12 of interlayer: the service life of the contrast interlayer is 8-15 times due to different materials, and the time of the whole failure process is relatively delayed. The Cr2O3 interlayer has partial cracks and small parts of falling off in the early sintering process, and a large amount of cracks and falling off in the later sintering process. During the early sintering process of the Al2O3 interlayer, obvious cracking and bonding phenomena do not occur in the interlayer, and during the later sintering process, the surface of the interlayer gradually cracks, and finally the interlayer falls off in a large amount to fail. During the early sintering period of the Al2O3+ 30% Y2O3 and ZrO2+ 25% SiO2 interlayer, the interlayer slightly adheres to a sintered product, during the later sintering period, a contact area between a sintered sample and the interlayer is partially fallen off due to adhesion at the bottom of the sintered sample to cause failure, and meanwhile, impurities of Y elements with different degrees appear on the surface of the Al2O3+ 30% Y2O3 interlayer sintered sample.

And (3) separation layer 13: compared with the interlayer Al2O3+ 25% SiO2, the thickness of the interlayer becomes thinner, the adhesion phenomenon of a sintered sample and an interlayer contact area occurs, and in the later sintering process, the interlayer of the contact area completely falls off and fails.

The separation layer 14: compared with the porosity increase of the interlayer Al2O3+ 30% Cr2O3, the middle separation layer has slight cracking in the early sintering process, and the whole interlayer has serious cracking and falling off in the later sintering process to fail.

Example 4

The interlayer for sintering the hard alloy compact has the blade model of CNMG120404, the compact is medium-particle hard alloy, the average WC grain diameter is 2.0um, and the mass percent of Co is 8%. The spacer material selection was the same as in example 1.

The molding information and the characteristic index of each interlayer are shown in Table 4.

TABLE 4 interlayer formation information and characteristic index

And (3) placing the pressed product on different burning bearing plate interlayers, wherein the sintering temperature is 1450 ℃, sintering for 60min, cooling to the temperature below 1000 ℃ at the cooling rate of 10-100 ℃/min, then naturally cooling, then unloading the alloy, placing the pressed product on the interlayers for secondary sintering, and repeatedly sintering and cooling until the burning bearing plate interlayers fail.

1-5 of interlayer: the service life of the interlayer is 15-23 times, the surface of the interlayer is complete in the early sintering process, no local or overall falling or cracking occurs, the sintered product can be easily dismounted, and the surface is not abnormal. In the later sintering process, the contact area between the sintered sample and the interlayer is failed due to local falling caused by the bonding of the bottom of the sintered sample, the sintered product needs to be dismounted with little force, and the interlayer material of the bonding part on the surface of the sintered sample is sintered.

And (3) an interlayer 6: compared with the service life of the interlayer ZrO2+ 8% Y2O3, the interlayer is slightly bonded with a sintered product in the early sintering process, the sintered sample and the interlayer contact area are partially fallen off and become invalid due to the serious bonding of the bottom of the sintered sample in the later sintering process, the sintered product needs to be unloaded forcibly, and a large amount of interlayer materials are bonded on the surface of the sintered sample.

7-8 of interlayer: compared with the interlayer Al2O3+ 25% SiO2 and Al2O3+ 30% Cr2O3, the plasma spraying technology is adopted, a large amount of cracks appear in the early sintering process, the phenomenon of partial falling exists, and the interlayer fails due to the serious and complete falling of the cracks in the later sintering process.

9-12 of interlayer: compared with the service life of the interlayer of 3-9 times due to different materials, the time of the whole failure process is relatively advanced. The Cr2O3 interlayer has partial cracks and partial falling-off phenomena in the early sintering process, and a large amount of cracks and total falling-off phenomena in the later sintering process. During the early sintering process of the Al2O3 interlayer, the interlayer has slight cracking, and during the later sintering process, the surface of the interlayer has severe cracking, and finally the interlayer falls off in a large amount to fail. During the early sintering period of the Al2O3+ 30% Y2O3 and ZrO2+ 25% SiO2 interlayer, the interlayer is bonded with a sintered product, during the later sintering period, the sintered sample and the interlayer contact region fall off due to serious bonding at the bottom of the sintered sample to cause failure, and meanwhile, the surface of the Al2O3+ 30% Y2O3 interlayer sintered sample is contaminated by Y elements in different degrees.

And (3) separation layer 13: compared with the interlayer Al2O3+ 25% SiO2, the thickness of the interlayer is reduced, the adhesion phenomenon of a sintered sample and an interlayer contact area occurs, and in the later sintering process, the interlayer of the contact area is completely adhered and falls off to fail.

The separation layer 14: compared with the porosity increase of the interlayer Al2O3+ 30% Cr2O3, the middle separation layer has a cracking phenomenon in the early sintering process, and the whole interlayer has serious cracking and falling off and fails in the later sintering process.

The sintering result shows that the invention adopts the flame spraying technology, selects the spraying material consisting of more than two (including two) oxides of Al2O3, SiO2, TiO2, MgO, Cr2O3 and ZrO2 with the granularity ranging from 1um to 150um, controls the total film thickness of the interlayer to be 50um to 500um, controls the porosity to be 1 percent to 30 percent, can effectively prolong the service life and contact reaction of the interlayer, plays a good role in blocking the hard alloy pressed product and the burning bearing plate, and provides a qualified alloy body.

The interlayer for sintering the hard alloy pressed product is formed on the burning bearing plate by adopting a flame spraying technology under a certain condition by selecting two or more oxides of Al2O3 (aluminum oxide), SiO2 (silicon dioxide), TiO2 (titanium dioxide), MgO (magnesium oxide), Cr2O3 (chromium oxide) and ZrO2 (zirconium dioxide) which have thermal expansion coefficients similar to those of the burning bearing plate, can reduce the difference between the forming temperature and the sintering use temperature of the interlayer, avoids the physicochemical change of each component of the interlayer during forming and sintering, and ensures that the prepared interlayer not only obstructs the physicochemical reaction between the hard alloy pressed product and the burning bearing plate, but also reduces the physicochemical change of the interlayer as far as possible, thereby obviously prolonging the service life of the interlayer in the sintering application of the hard alloy pressed product.

The foregoing is considered as illustrative of the preferred embodiments of the invention and is not to be construed as limiting the invention in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or equivalent modifications, without departing from the scope of the disclosed embodiments. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.