Low-temperature brazing method for CVD-Heater AlN ceramic disc and ceramic shaft

Abstract

The invention discloses a low-temperature brazing method for a CVD-Heater AlN ceramic disc and a ceramic shaft, and belongs to the technical field of battery charging, and the low-temperature brazing method comprises the following steps: S1, preparing a glass brazing material: using CaO and Al2O3 as glass phase raw materials, firstly mixing, melting at high temperature, then performing water quenching and ball milling to prepare CA glass to play a role in bonding, then adding Si3N4 in a certain proportion, and then performing ball milling to obtain the glass brazing material; the expansion coefficient of CA glass is improved to be matched with AlN ceramic, terpilenol and ethyl cellulose are used as organic additives to be mixed to prepare glass brazing slurry, and the glass brazing slurry is used for conducting low-temperature brazing on a ceramic disc and a ceramic shaft; s2, gluing is conducted, specifically, glass brazing slurry is smeared on the bonding face of the ceramic disc or the ceramic shaft, and smearing is completed through silk-screen printing or a smearing pen; s3, high-temperature bonding is conducted, specifically, the temperature is increased to 1000 DEG C at the heating rate of 5 DEG C / min before bonding, then the temperature is increased to 1450 DEG C at the heating rate of 3 DEG C / min, the atmosphere is N2 or vacuum, and bonding of the ceramic disc and the ceramic shaft is conducted after heat preservation is conducted for 2 h; and S4, testing after bonding.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic heaters, in particular to a low-temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft. Background Art

[0002] In the preparation process of AlN ceramic CVD-heater, bonding of ceramic disk and ceramic shaft is a very important process. In the prior art, the bonding process mainly realizes the connection between AlN ceramic disk and ceramic shaft through high temperature process. For example, the bonding temperature mentioned in Japanese Patent Gazette No. 8-73280, Gazette No. 10-167850 and Gazette No. 10-273370 is above 1650℃, but such high temperature will bring many adverse effects on the product. For example, during high temperature bonding, the product is at risk of deformation and cracking, and the ceramic grains will grow secondary, resulting in deterioration of ceramic volume resistivity and mechanical strength. At the same time, the difference in thermal expansion coefficients between metal electrode materials and ceramic materials in high temperature environment increases, which is easy to produce micro cracks at the joint, leading to the risk of deterioration of adsorption and heating performance. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a low-temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft to solve the problem raised in the background technology.

[0004] In order to solve the above technical problems, the technical solution of the present invention is:

[0005] A low temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft, the method comprising:

[0006] S1: Glass brazing material preparation using CaO and Al 2 O 3 The raw materials for the glass phase are first mixed and melted at high temperature and then quenched and ball-milled to prepare CA glass, in which CaO accounts for 40-60% of CA glass, Al 2 O 3 The proportion of is 60-40%, which plays a bonding role, and then a certain proportion of Si is added 3 N 4 , which improves the expansion coefficient of CA glass to match AlN ceramics, and mixes pine alcohol and ethyl cellulose as organic additives to prepare glass brazing slurry for low-temperature brazing of ceramic disks and ceramic shafts;

[0007] S2: Gluing: Apply the glass brazing paste on the bonding surface of the ceramic disk or ceramic shaft by screen printing or a smear pen;

[0008] S3: High temperature bonding: before bonding, the temperature was raised to 1000°C at a heating rate of 5°C / min, and then raised to 1450°C at a heating rate of 3°C / min. The atmosphere was N 2 Or vacuum, keep warm for 2 hours and then perform bonding between the ceramic disk and the ceramic shaft;

[0009] S4: After bonding, the He leakage rate of the test sample is less than 1*10 -9 Pa·m / s, the leakage rate after 100 times of 0~700℃ temperature shock is still less than 1*10 -9 Pa·m / s, no obvious decrease, the initial bending strength of the sample block is> 250MPa, at 700℃NF 3 After 100h of corrosion aging in a corrosive gas environment, the bonding strength of the tested corrosion samples was >250Mpa, with no significant decrease.

[0010] Preferably, in step S1, the source of CaO is CaO, Ca(OH) 2 or CaCO 3 .

[0011] Preferably, in step S1, the Al 2 O 3 The source is Al 2 O 3 or Al(OH) 3 .

[0012] Preferably, in step S1, the Si 3 N 4 The raw material is α-Si 3 N 4 or β-Si 3 N 4 .

[0013] Preferably, in step S1, CA (CaO-Al 2 O 3 )-Si 3 N 4 CA accounts for 60-99.99% of the ratio, Si 3 N 4 It accounts for 0.01% to 40%.

[0014] Preferably, the CA glass contains 45-55% CaO and 55% Al. 2 O 3 The proportion is 55-45%.

[0015] Preferably, the CA (CaO-Al 2 O 3 )-Si3 N 4 In the ratio of Si 3 N 4 It accounts for 10 to 30%.

[0016] The above technical solution has the following beneficial effects:

[0017] The present application discloses a glass brazing method for low-temperature bonding of CVD-Heater AlN ceramic disks and ceramic shafts; the method not only meets the use requirements of the AlN ceramic CVD-heater after bonding, but also reduces the bonding temperature, and avoids deformation and cracking of the product in the previous high-temperature bonding process, secondary growth of ceramic grains leading to deterioration of properties such as ceramic volume resistivity and mechanical strength, and avoids the increase in the difference in thermal expansion coefficients between metal electrode materials and ceramic materials in a high-temperature environment, which easily generates microcracks at the joint, leading to the risk of deterioration of adsorption and heating performance; at the same time, the bonding temperature also reduces the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The CaO-Al 2 O 3 Binary phase diagram. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Example 1

[0021] A low temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft, comprising:

[0022] S1: Glass brazing material preparation using CaO and Al 2 O 3 The raw materials for the glass phase are first mixed and melted at high temperature and then quenched and ball-milled to prepare CA glass, which plays a bonding role. Then a certain proportion of Si is added 3 N 4 , which improves the expansion coefficient of CA glass to match AlN ceramics, and mixes pine alcohol and ethyl cellulose as organic additives to prepare glass brazing slurry for low-temperature brazing of ceramic disks and ceramic shafts;

[0023] refer to Figure 1 , CaO-Al in CA glass 2 O3 Proportion Figure 1 The shaded area is selected, the mass ratio of CaO is 40-60%, the mass ratio of Al2O3 is 60-40%, and the total ratio of the two is 100%. CA glass can be directly combined with raw materials, or it can be melted at high temperature and then quenched by water to produce CA glass;

[0024] The main formula of glass brazing material is CaO-Al 2 O 3 -Si 3 N 4 , of which CaO-Al 2 O 3 The glass formed at high temperature plays the role of bonding the AlN disk and the AlN shaft. 3 N 4 It is an optimization machine for expansion coefficient and mechanical properties, and plays a role in improving CaO-Al 2 O 3 The expansion coefficient of glass is matched to AlN ceramics, while Si 3 N 4 The mechanical properties of ceramics are better than those of CaO-Al 2 O 3 Glass, which improves the high temperature strength and fracture toughness of the entire glass brazing material;

[0025] The source of CaO can be CaO, Ca(OH) 2 or CaCO 3 , Al 2 O 3 The source is Al 2 O 3 or Al(OH) 3 , Si 3 N 4 The raw material is α-Si 3 N 4 or β-Si 3 N 4 ;

[0026] CA(CaO-Al 2 O 3 )-Si 3 N 4 CA accounts for 60-99.99% of the ratio, Si 3 N 4 The proportion is 0.01-40%, and the preferred CA glass has a CaO proportion of 45-55%, and Al 2 O 3 The proportion of CA (CaO-Al 2 O 3 )-Si 3 N 4In the ratio of Si 3 N 4 10-30%;

[0027] The brazing material is CaO-Al 2 O 3 -Si 3 N 4 , of which CaO-Al 2 O 3 CA glass is formed at high temperature to bond the AlN disk and AlN shaft. 3 N 4 It is an optimization machine for expansion coefficient and mechanical properties, and plays a role in improving CaO-Al 2 O 3 The expansion coefficient of glass is matched to AlN ceramics, while Si 3 N 4 The mechanical properties of ceramics are better than those of CaO-Al 2 O 3 Glass, which improves the high temperature strength and fracture toughness of the entire glass brazing material;

[0028] S2: Gluing: Apply the glass brazing paste on the bonding surface of the ceramic disk or ceramic shaft, where the bonding surface is the bonding side, by screen printing or a smear pen;

[0029] S3: High temperature bonding: before bonding, the temperature was raised to 1000°C at a heating rate of 5°C / min, and then raised to 1450°C at a heating rate of 3°C / min. The atmosphere was N 2 Or vacuum, keep warm for 2 hours and then bond the ceramic disk and the ceramic shaft; first, the bonding temperature of the prior art exceeds 1500°C, such as the 1650°C bonding temperature disclosed in the background technology, and the bonding temperature of the present application is relatively low;

[0030] S4: After bonding, the He leakage rate of the test sample is less than 1*10 -9 Pa·m / s, the leakage rate after 100 times of 0~700℃ temperature shock is still less than 1*10 -9 Pa·m / s, no obvious decrease, the initial bending strength of the sample block is> 250MPa, at 700℃NF 3 After 100h of corrosion aging in a corrosive gas environment, the bonding strength of the tested corroded samples was >250Mpa, with no significant decrease;

[0031] The bonding temperature of this application is below 1500℃, and the bonding joint is resistant to high and low temperature impact and CVD process NF 3 、NCl 3Gas corrosiveness, He leakage within 1*10 -9 Glass solder with a certain bonding strength under Pa·m3 / s;

[0032] The present application discloses a glass brazing method for low-temperature bonding of CVD-Heater AlN ceramic disks and ceramic shafts; the method not only meets the use requirements of the AlN ceramic CVD-heater after bonding, but also reduces the bonding temperature, and avoids deformation and cracking of the product in the previous high-temperature bonding process, secondary growth of ceramic grains leading to deterioration of properties such as ceramic volume resistivity and mechanical strength, and avoids the increase in the difference in thermal expansion coefficients between metal electrode materials and ceramic materials in a high-temperature environment, which easily generates microcracks at the joint, leading to the risk of deterioration of adsorption and heating performance; at the same time, the bonding temperature also reduces the manufacturing cost.

[0033] Example 2

[0034] A low temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft, comprising:

[0035] Glass brazing material preparation using CaO and Al 2 O 3 The raw materials for the glass phase are first mixed and melted at high temperature and then quenched and ball-milled to prepare CA glass, which plays a bonding role. Then a certain proportion of Si is added 3 N 4 , which improves the expansion coefficient of CA glass to match AlN ceramics, and mixes pine alcohol and ethyl cellulose as organic additives to prepare glass brazing slurry for low-temperature brazing of ceramic disks and ceramic shafts;

[0036] Among them, the source of CaO is CaCO 3 , Al 2 O 3 The source is Al(OH) 3 , Si 3 N 4 The raw material is α-Si 3 N 4 ;CA(CaO-Al 2 O 3 )-Si 3 N 4 CA accounts for 60%, Si 3 N 4 Accounting for 40%, CaO accounts for 45% in CA glass, Al 2 O 3 The proportion is 55%;

[0037] S2: Gluing: Apply the glass brazing paste on the bonding surface of the ceramic disk or ceramic shaft by screen printing or a smear pen;

[0038] S3: High temperature bonding: before bonding, the temperature was raised to 1000°C at a heating rate of 5°C / min, and then raised to 1450°C at a heating rate of 3°C / min. The atmosphere was N 2 Or vacuum, keep warm for 2 hours and then perform bonding between the ceramic disk and the ceramic shaft;

[0039] S4: After bonding, the He leakage rate of the test sample is less than 1*10 -9 Pa·m / s, the leakage rate after 100 times of 0~700℃ temperature shock is still less than 1*10 -9 Pa·m / s, no obvious decrease, the initial bending strength of the sample block is> 250MPa, at 700℃NF 3 After 100h of corrosion aging in a corrosive gas environment, the bonding strength of the tested corrosion samples was >250Mpa, with no significant decrease.

[0040] Example 3

[0041] A low temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft, comprising:

[0042] Glass brazing material preparation using CaO and Al 2 O 3 The raw materials for the glass phase are first mixed and melted at high temperature and then quenched and ball-milled to prepare CA glass, which plays a bonding role. Then a certain proportion of Si is added 3 N 4 , which improves the expansion coefficient of CA glass to match AlN ceramics, and mixes pine alcohol and ethyl cellulose as organic additives to prepare glass brazing slurry for low-temperature brazing of ceramic disks and ceramic shafts;

[0043] Among them, the source of CaO is CaCO 3 , Al 2 O 3 The source is Al(OH) 3 , Si 3 N 4 The raw material is β-Si 3 N 4 ;CA(CaO-Al 2 O 3 )-Si 3 N 4 CA accounts for 90%, Si 3 N 4 Accounting for 10%, CaO accounts for 55% in CA glass, Al2 O 3 The proportion of is 45%;

[0044] In other embodiments of this embodiment, A(CaO-Al 2 O 3 )-Si 3 N 4 CA accounts for 70%, Si 3 N 4 Accounting for 30%, CaO accounts for 50% in CA glass, Al 2 O 3 The proportion is 50%;

[0045] In other embodiments of this embodiment, A(CaO-Al 2 O 3 )-Si 3 N 4 CA accounts for 80%, Si 3 N 4 It accounts for 20%.

[0046] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A low temperature brazing method for CVD-Heater AlN ceramic disk and ceramic shaft, characterized in that: The method comprises: S1: Preparation of glass brazing material, using CaO and Al2O3 as glass phase raw materials, first mixing and melting at high temperature and then quenching with water and ball milling to prepare CA glass, wherein CaO accounts for 40-60% of CA glass and Al2O3 accounts for 60-40% to play a bonding role, and then adding a certain proportion of Si3N4 to improve the expansion coefficient of CA glass to match AlN ceramics, and mixing with pine alcohol and ethyl cellulose as organic additives to prepare glass brazing slurry, which is used for low-temperature brazing of ceramic disks and ceramic shafts; S2: Gluing: Apply the glass brazing paste on the bonding surface of the ceramic disk or ceramic shaft by screen printing or a smear pen; S3: High temperature bonding: before bonding, the temperature is raised to 1000°C at a heating rate of 5°C / min, and then raised to 1450°C at a heating rate of 3°C / min. The atmosphere is N2 or vacuum. After keeping the temperature for 2 hours, the ceramic disk and the ceramic shaft are bonded. S4: After bonding, the He leakage rate of the test sample is less than 1*10 -9 Pa·m / s, the leakage rate after 100 times of 0~700℃ temperature shock is still less than 1*10 -9 Pa·m / s, there is no obvious decrease. The initial bending strength of the sample is>250MPa. After corrosion aging in 700℃ NF3 corrosive gas environment for 100h, the bonding strength of the tested corrosion sample is>250Mpa, with no obvious decrease.

2. A low temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft according to claim 1, characterized in that: In the step S1, the source of CaO is CaO, Ca(OH)2 or CaCO3.

3. A low temperature brazing method for CVD-Heater AlN ceramic disk and ceramic shaft according to claim 1, characterized in that: In the step S1, the source of the Al2O3 is Al2O3 or Al(OH)3.

4. A low temperature brazing method for a CVD-Heater AlN ceramic disk and a ceramic shaft according to claim 1, characterized in that: In the step S1, the raw material of Si3N4 is α-Si3N4 or β-Si3N4.

5. A low temperature brazing method for CVD-Heater AlN ceramic disk and ceramic shaft according to claim 1, characterized in that: In the step S1, in the ratio of CA (CaO-Al2O3)-Si3N4, CA accounts for 60-99.99% and Si3N4 accounts for 0.01-40%.

6. A low temperature brazing method for CVD-Heater AlN ceramic disk and ceramic shaft according to claim 5, characterized in that: In the CA glass, CaO accounts for 45-55%, and Al2O3 accounts for 55-45%.

7. A low temperature brazing method for CVD-Heater AlN ceramic disk and ceramic shaft according to claim 5, characterized in that: In the ratio of CA (CaO-Al2O3)-Si3N4, Si3N4 accounts for 10-30%.

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