CN113862604A - Contact probe diagnostic device and method for plasma spraying under low vacuum condition - Google Patents
Contact probe diagnostic device and method for plasma spraying under low vacuum condition Download PDFInfo
- Publication number
- CN113862604A CN113862604A CN202110914737.4A CN202110914737A CN113862604A CN 113862604 A CN113862604 A CN 113862604A CN 202110914737 A CN202110914737 A CN 202110914737A CN 113862604 A CN113862604 A CN 113862604A
- Authority
- CN
- China
- Prior art keywords
- unit
- probe
- plasma
- plasma jet
- low
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
- C23C4/134—Plasma spraying
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Plasma & Fusion (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Coating By Spraying Or Casting (AREA)
Abstract
The invention discloses a contact probe diagnosis device and a method for plasma spraying under low vacuum conditions, and relates to the technical field of plasma spraying under low vacuum conditions. The device comprises a signal acquisition probe unit and a high-temperature contact protection unit which are arranged in a low-voltage chamber, a probe power supply unit arranged outside the low-voltage chamber, and an auxiliary circuit unit used for connecting the signal acquisition probe unit and the probe power supply unit.
Description
Technical Field
The invention relates to the technical field of plasma spraying under a low vacuum condition, in particular to a contact probe diagnosis device and method for plasma spraying under the low vacuum condition.
Background
The plasma spraying technology is a method of using direct current non-transferred arc plasma as a heat source to heat materials such as ceramics, alloys, metals and the like to a molten or semi-molten state, and spraying the materials to the surface of a pretreated substrate at a high speed so as to form a firmly-adhered coating. Compared with the traditional atmospheric plasma spraying technology and gas-phase physical deposition, the low-pressure plasma spraying technology can prepare a coating which is more compact, less in inclusion and higher in bonding strength.
In the low vacuum low pressure plasma spraying method, the maximum temperature exceeds 12000K, the speed exceeds 6000m/s, and a low pressure chamber with huge volume (such as a cylindrical pressure vessel, the length is 2.7 meters, and the diameter is 1.1 meter) exists, and the conditions bring huge challenges to the synchronous experimental detection. In a supersonic flow field with the length meter scale, the flow and transmission of a plurality of phases (micron or nanometer scale) are included, and the complex interaction of supersonic flow, vortex flow, shock wave and material phase change is involved. At present, the knowledge of the flow and heat and mass transfer of plasma jet in a closed cavity is not sufficient, the existing experimental detection method cannot be realized in a low-pressure cabin, and cannot provide global field distribution, particularly the electron temperature and the space potential of the plasma jet in the flying process of a powder material.
Disclosure of Invention
The embodiment of the invention provides a contact probe diagnosis device and method for plasma spraying under a low vacuum condition, which can obtain the electron temperature and suspension potential distribution of a low-pressure supersonic speed expanding plasma jet at different positions in real time so as to overcome the technical problems, synchronously monitor the states of the plasma jet and a metal matrix in the low vacuum plasma spraying process, improve the production efficiency, find faults in time and simultaneously have no interference and other influences on the fluid dynamics characteristics of the arc plasma jet under the low vacuum.
In order to solve the above problems, an embodiment of the present invention discloses a contact probe diagnostic apparatus for plasma spraying under a low vacuum condition, the apparatus including:
the high-temperature contact protection unit is arranged between a plasma jet and the signal acquisition probe unit, and a detection end of the signal acquisition probe unit passes through the high-temperature contact protection unit and then contacts with the plasma jet in the low-pressure chamber, and generates a changed voltage signal along with the parameter change of the plasma jet;
the probe power supply unit is arranged outside the low-voltage cabin, and the auxiliary circuit unit is used for connecting the probe power supply unit with the output end of the signal acquisition probe unit;
the probe power supply unit is used for supplying power to the signal acquisition probe unit through the auxiliary circuit unit and monitoring the space suspension potential and/or the electronic temperature of the plasma jet in the spraying process according to the changed voltage signal.
In an embodiment of the present invention, the high temperature contact protection unit includes a high temperature resistant alloy substrate and a ceramic coating deposited on the high temperature resistant alloy substrate, the ceramic coating faces the plasma jet, the high temperature resistant alloy substrate faces the signal acquisition probe unit, and the ceramic coating is used for supporting the high temperature contact protection unit to operate under conditions of 14000K and 6000 m/s.
In an embodiment of the invention, a moving track is distributed on the inner wall of the low-pressure cabin, a sliding block is arranged at the bottom of the high-temperature contact protection unit, and the sliding block and the moving track are matched with each other; the movable rail and the sliding block are both made of high-temperature-resistant materials, and the high-temperature-resistant materials are used for supporting the movable rail and the sliding block to work under the conditions of 14000K and 6000 m/s.
In an embodiment of the invention, the radial length of the high-temperature contact protection unit moving in the low-pressure chamber is 10-500 mm, and the axial length is 100-1800 mm.
In an embodiment of the invention, the length of the probing end of the signal acquisition probe unit is greater than 10-50 mm.
In an embodiment of the present invention, the probing end of the signal collecting probe unit is made of tungsten, tantalum, or molybdenum.
In an embodiment of the present invention, the auxiliary circuit unit includes a wire and a plurality of ceramic rings, and the ceramic rings are sleeved on the wire at a predetermined distance.
In an embodiment of the invention, the probe power supply unit comprises a display screen, and the display screen is used for displaying and recording the spatial suspension potential and/or the electronic temperature of the plasma jet in the spraying process.
In order to solve the above problems, the embodiment of the present invention further discloses a method for diagnosing a contact probe for plasma spraying under a low vacuum condition, the method comprising:
determining a position to be diagnosed in a low-pressure chamber in a plasma spraying system under a low vacuum condition, connecting the contact probe diagnosis device for plasma spraying under the low vacuum condition, and placing a detection end of a signal acquisition probe unit in the device at the position to be diagnosed;
adjusting the low-pressure cabin to a target vacuum degree, and spraying plasma jet to the metal substrate by using a plasma generator in the plasma spraying system under the low vacuum condition; the detection end of the signal acquisition probe unit passes through the high-temperature contact protection unit and then contacts with the plasma jet to generate a first voltage signal;
starting a probe power supply unit in the device, and recording the first voltage signal corresponding to the position to be diagnosed by using the probe power supply unit;
adjusting parameters of the jet plasma jet, starting the probe power supply unit again, and recording the second voltage signal corresponding to the position to be diagnosed by using the probe power supply unit;
and calculating and obtaining the spatial suspension potential and/or the electronic temperature of the plasma jet at the position to be diagnosed in the spraying process according to the first voltage signal and the second voltage signal.
In one embodiment of the present invention, the vacuum degree of the low pressure chamber is adjusted in a range of 50Pa to 1000 Pa.
The embodiment of the invention has the following advantages:
the embodiment of the application discloses contact probe diagnostic device for plasma spraying under low vacuum condition, the device is including setting up signal acquisition probe unit and high temperature contact protection unit in the low-pressure cabin, setting up the probe power supply unit outside the low-pressure cabin to and be used for connecting signal acquisition probe unit and probe power supply unit's auxiliary line unit. The signal acquisition probe unit comprises a detection end, the detection end can be coupled with the plasma jet to obtain a coupling potential after being contacted with the plasma jet, so that a changed voltage signal can be generated along with the parameter change of the plasma, the signal acquisition probe unit can transmit the changed voltage signal to the probe power supply unit through the auxiliary circuit unit in real time, and the probe power supply unit can calculate the space suspension potential and/or the electronic temperature of the plasma jet in the spraying process after receiving the changed voltage signal. In the process, the high-temperature contact protection unit can impact and heat the front plasma jet, so that the plasma jet and the signal acquisition probe unit can be isolated based on a physical method, the signal acquisition probe unit can work in a low-vacuum low-pressure plasma spraying environment with the maximum temperature exceeding 12000K and the speed exceeding 6000m/s, the spatial suspension potential and/or the electronic temperature of the plasma jet can be detected (monitored) in real time, the production efficiency is improved, faults can be found in time, and meanwhile, the hydrodynamic characteristics of the arc plasma jet under low vacuum are not interfered and influenced. And because the auxiliary line unit is connected with the signal acquisition probe unit inside the low-pressure cabin and the external probe power supply unit, the stable transmission of the vacuum degree and the line signals of the system in the whole low-pressure cabin can be ensured.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic structural diagram of a contact probe diagnostic device for plasma spraying under a low vacuum condition according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of the construction of a low pressure chamber with moving rails according to an embodiment of the present invention;
FIG. 3a is a schematic structural diagram of a spiral moving track according to an embodiment of the present invention;
FIG. 3b is a schematic structural diagram of a wavy moving track according to an embodiment of the present invention;
FIG. 3c is a schematic structural diagram of a Wang-shaped moving rail according to an embodiment of the present invention;
FIG. 4 is a flow chart illustrating the steps of a method for diagnosing a contact probe for plasma spraying under a low vacuum condition, in accordance with an embodiment of the present invention.
Description of reference numerals:
1. the device comprises a low-pressure cabin, 2, a signal acquisition probe unit, 2-1, a probe end, 3, a high-temperature contact protection unit, 4, a probe power supply unit, 4-1, a display screen, 5, an auxiliary line unit, 5-1, an electric wire, 5-2, a ceramic ring, 6 and a moving track.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments 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.
In view of the technical problem of the present invention, referring to fig. 1, there is shown a contact probe diagnosis apparatus for plasma spraying under a low vacuum condition, which may include:
the device comprises a signal acquisition probe unit 2 and a high-temperature contact protection unit 3 which are arranged in a low-pressure cabin 1 in a plasma spraying system under the condition of low vacuum, wherein the high-temperature contact protection unit 3 is arranged between a plasma jet and the signal acquisition probe unit 2, a detection end 2-1 of the signal acquisition probe unit 2 passes through the high-temperature contact protection unit 3 and then contacts with the plasma jet in the low-pressure cabin 1, and a changed voltage signal is generated along with the parameter change of the plasma jet;
a probe power supply unit 4 disposed outside the low pressure cabin 1, and an auxiliary line unit 5 for connecting the probe power supply unit 4 with an output terminal of the signal collecting probe unit 2; the probe power supply unit 4 is used for supplying power to the signal acquisition probe unit 2 through the auxiliary line unit 5, and is used for monitoring the space suspension potential and/or the electronic temperature of the plasma jet in the spraying process according to the changed voltage signal.
In the present invention, the plasma spray system under a low vacuum condition may further include, in addition to the low pressure chamber 1: base member centre gripping the control unit, be located the plasma generation unit directly over the metal substrate to and the jet stabilization control unit who is connected respectively with plasma generation unit and send whitewashed the control unit, wherein: the substrate clamping control unit is used for clamping the metal substrate in the low-pressure cabin 1, controlling the metal substrate to be vertical to the plasma jet and controlling the temperature of the metal substrate in the spraying process; the plasma generating unit is used for spraying plasma jet to the metal matrix in the low-pressure cabin 1; the jet flow stabilization control unit is used for controlling the plasma jet flow in the low-pressure cabin 1 to reciprocate on the surface of the metal substrate at a certain scanning speed and a certain spraying interval; the powder feeding control unit is used for feeding ceramic powder into the plasma jet in the low-pressure chamber 1. The working environment pressure of the low-pressure cabin 1 is 50Pa to 1000Pa, the working gas of the plasma generation unit is argon and helium mixed gas, the power of a plasma spray gun of the plasma generation unit is 60-80 kW, the total gas flow is 90-120 SLPM, the highest outlet temperature is 14000K, and the highest speed exceeds 6000 m/s.
Aiming at the plasma spraying system under the low vacuum condition, the invention provides a device for diagnosing the plasma jet electron temperature and the space suspension point position of the system, which comprises a signal acquisition probe unit 2 and a high-temperature contact protection unit 3 which are arranged in a low-pressure cabin 1, a probe power supply unit 4 which is arranged outside the low-pressure cabin 1, and an auxiliary line unit 5 which is used for connecting the signal acquisition probe unit 2 and the probe power supply unit 4. The signal acquisition probe unit 2 comprises a detection end 2-1, and the detection end 2-1 can be coupled with the plasma jet to obtain a coupling potential after being contacted with the plasma jet, so that a variable voltage signal can be generated along with the parameter change of the plasma. The signal acquisition probe unit 2 can detect the plasma jet based on the Langmuir probe detection principle, and for the Langmuir probe detection principle, reference may be made to related technologies, which are not repeated herein. Because the signal acquisition probe unit 2 is connected to the probe power supply unit 4 through the auxiliary line unit 5, the signal acquisition probe unit 2 can transmit the changed voltage signal to the probe power supply unit 4 through the auxiliary line unit 5 in real time, the probe power supply unit 4 can calculate the spatial suspension potential and/or the electronic temperature of the plasma jet in the spraying process after receiving the changed voltage signal, and the principle of how to calculate the spatial suspension potential and/or the electronic temperature of the plasma jet in the spraying process according to the changed voltage signal by the probe power supply unit 4 can refer to a related calculation method, which is not described herein again. The probe power supply unit 4 of the invention is a high-power device, and ensures accurate and real-time output of the measured data of the signal acquisition probe unit 2. In the process, the high-temperature contact protection unit 3 can impact and heat the front plasma jet, so that the plasma jet and the signal acquisition probe unit 2 can be isolated based on a physical method, the signal acquisition probe unit 2 can work in a low-vacuum low-pressure plasma spraying environment with the highest temperature exceeding 12000K and the speed exceeding 6000m/s, the spatial suspension potential and/or the electronic temperature of the plasma jet can be detected (monitored) in real time, the production efficiency is improved, faults can be found in time, and meanwhile, the hydrodynamic characteristics of the arc plasma jet under low vacuum are not interfered and influenced. And because the auxiliary line unit 5 is adopted to connect the signal acquisition probe unit 2 inside the low-pressure cabin 1 and the external probe power supply unit 4, the vacuum degree of the system in the whole low-pressure cabin 1 and the stable transmission of line signals can be ensured.
In one embodiment of the present invention, the probe end 2-1 of the signal collection probe unit 2 is made of tungsten, tantalum or molybdenum. The tungsten, tantalum or molybdenum material has high melting point, the melting point is more than 2500 ℃, the detection end 2-1 of the signal acquisition probe unit 2 is prepared from the tungsten, tantalum or molybdenum material, the ultrahigh temperature of the plasma jet can be resisted, a variable voltage signal is generated along with the parameter change of the plasma jet, and the detection end 2-1 is ensured not to be melted. The detection end 2-1 of the signal acquisition probe unit 2 is in a direct contact type and is in a strip shape (such as a cylindrical shape), and the length of the detection end 2-1 of the signal acquisition probe unit 2 is larger than 10-50 mm, so that the signal acquisition probe unit can penetrate 10-50 mm into the plasma jet, and simultaneously the fluid flowing state of the plasma jet is not influenced.
In an embodiment of the present invention, the high temperature contact protection unit 3 includes a high temperature resistant alloy substrate and a ceramic coating deposited on the high temperature resistant alloy substrate, the ceramic coating faces the plasma jet, the high temperature resistant alloy substrate faces the signal acquisition probe unit 2, wherein the ceramic coating is used for supporting the high temperature contact protection unit 3 to operate under the conditions of 14000K and 6000 m/s. Specifically, the high-temperature contact protection unit 3 may be a plate-shaped structure, that is, the inner side of the plate-shaped structure is used for installing the signal acquisition probe unit 2, the outer side of the plate-shaped structure is provided with a ceramic coating, and the plate-shaped structure is provided with a small hole through which the detection end 2-1 of the signal acquisition probe unit 2 can pass. Because the plasma jet is longer, the plate-shaped structure can be longer along the length direction of the plasma jet, so that the influence of the high temperature of the plasma jet on the signal acquisition probe unit 2 can be better isolated. The high-temperature contact protection unit 3 can also be a cavity structure, i.e. the signal acquisition probe unit 2 is arranged in the cavity of the cavity structure, the outer surface of the cavity is a ceramic coating, and a small hole is formed in the cavity and can be used for the detection end 2-1 of the signal acquisition probe unit 2 to penetrate out.
In an embodiment of the invention, referring to fig. 2, a moving rail 6 is arranged on the inner wall of the ballast 1, and a slide block (not shown) is arranged at the bottom of the high-temperature contact protection unit 3, and the slide block and the moving rail 6 are matched with each other; the moving track 6 and the sliding block are both made of high-temperature-resistant materials, and the high-temperature-resistant materials are used for supporting the moving track 6 and the sliding block to work under the conditions of 14000K and 6000 m/s. In the invention, referring to fig. 3a to 3c, the moving track 6 may be arranged on the inner wall of the low pressure chamber 1 in a spiral shape, a wave shape or a shape similar to a king (the shape similar to a king includes a vertical line and a plurality of horizontal lines, the plurality of horizontal lines are distributed along the vertical line at preset intervals and are perpendicular to the vertical line), wherein the extension direction of the spiral shape or the wave shape is the same direction as the axial direction of the plasma jet (the axial direction of the plasma jet is the spraying direction of the plasma jet), the vertical line similar to a king is parallel to the axial direction of the plasma jet, and a plurality of horizontal lines parallel arranged in a shape similar to a king are perpendicular to the axial direction of the plasma jet. Therefore, the high-temperature contact protection unit 3 can move along the axial direction of the plasma jet and can move along the radial direction of the plasma jet, the signal acquisition probe unit 2 can detect the plasma jet at different spatial positions, the signal acquisition probe unit 2 transmits voltage signals generated by detection to the probe power supply unit 4 through the auxiliary circuit unit 5, and the electronic temperature and suspension potential distribution of the low-voltage supersonic expansion type plasma jet at different positions can be obtained in real time. It should be noted that the refractory material may be only an alloy material, or may be a metal alloy material and a coating material, such as a refractory alloy substrate and a ceramic coating deposited on the refractory alloy substrate.
In an embodiment of the present invention, the radial length of the high temperature contact protection unit 3 moving in the low pressure chamber 1 is 10-500 mm, and the axial length is 100-1800 mm, so that a wider moving range is realized in the low pressure chamber 1, and further, a wider free detection range is realized by the signal acquisition probe unit 2.
In the specific implementation, the radial length of the movable track 6 in the low-pressure chamber 1 may be 10-500 mm, and the axial length may be 100-1800 mm. Namely, when the moving track 6 is spiral, the extension length of the spiral moving track 6 is 100-1800 mm, and the radial expansion size is 10-500 mm; when the movable track 6 is wavy, the extending length of the wavy movable track 6 is 100-1800 mm, and the distance between the wave crests and the wave troughs is 10-500 mm; when the moving track 6 is in a shape like a Chinese character 'wang', the length of a vertical line of the moving track 6 in the shape like the Chinese character 'wang' is 100-1800 mm, and the length of each transverse line is 10-500 mm.
In an embodiment of the present invention, the auxiliary circuit unit 5 includes an electric wire 5-1 and a plurality of ceramic rings 5-2, and the plurality of ceramic rings 5-2 are sleeved on the electric wire 5-1 at a predetermined interval. The ceramic ring 5-2 plays an insulating role, and can ensure the safety and signal stability of the transmission wire 5-1 in the plasma spraying diagnosis process.
In an embodiment of the present invention, the probe power supply unit 4 includes a display screen 4-1, and the display screen 4-1 is used for displaying and recording the spatial levitation potential and/or the electron temperature of the plasma jet in the spraying process, so that a user can know the spatial levitation potential and/or the electron temperature of the plasma jet in the spraying process in real time, and adjust and optimize related parameters of the plasma spraying in real time.
Based on the same inventive concept, referring to fig. 4, the embodiment of the invention also discloses a method for diagnosing the contact probe for plasma spraying under the low vacuum condition, which comprises the following steps:
step S1, determining the position to be diagnosed in the low-pressure chamber 1 of the plasma spraying system under the low vacuum condition, connecting the contact probe diagnosis device for plasma spraying under the low vacuum condition according to the embodiment of the invention, and placing the detection end 2-1 of the signal acquisition probe unit 2 in the device at the position to be diagnosed;
step S2, adjusting the low pressure cabin 1 to a target vacuum degree, and spraying plasma jet to the metal substrate by using a plasma generator in the plasma spraying system under the low vacuum condition; the detection end 2-1 of the signal acquisition probe unit 2 penetrates through the high-temperature contact protection unit 3 and then contacts with the plasma jet, and a first voltage signal is generated; in one embodiment of the present invention, the vacuum degree of the low pressure cabin 1 is adjusted in a range of 50Pa to 1000 Pa.
Step S3, starting a probe power supply unit 4 in the device, and recording the first voltage signal corresponding to the position to be diagnosed by using the probe power supply unit 4;
step S4, adjusting parameters of the jet plasma jet, starting the probe power supply unit 4 again, and recording the second voltage signal corresponding to the position to be diagnosed by using the probe power supply unit 4; the parameters of the plasma jet may include the operating current of the plasma, the total gas flow of the operating gas.
And step S5, calculating and obtaining the spatial suspension potential and/or the electronic temperature of the plasma jet at the position to be diagnosed in the spraying process according to the first voltage signal and the second voltage signal.
Through the steps of S1 to S5, the embodiment of the present invention can obtain the electron temperature and the suspension potential distribution of the low-pressure supersonic expansion plasma jet at the position to be diagnosed in real time, and when the position to be diagnosed changes, the electron temperature and the suspension potential distribution obtained by calculation also change, so that the present invention realizes the monitoring of the electron temperature and the suspension potential distribution of the low-pressure supersonic expansion plasma jet at different positions. When the detection end 2-1 of the signal acquisition probe unit 2 is placed on the metal substrate, the embodiment of the invention can also calculate the sheath thickness of the metal substrate based on the changed voltage signal. The invention can synchronously monitor the states of the plasma jet and the metal matrix in the low-vacuum plasma spraying process, improve the production efficiency, find faults in time and simultaneously have no interference and other influences on the fluid dynamics characteristics of the arc plasma jet under low vacuum.
A method for diagnosing a contact probe for plasma spraying under a low vacuum condition will be further described with reference to several embodiments.
Example 1: single crystal high temperature alloy surface spray coating thermal barrier coating
The single crystal high-temperature alloy takes a single crystal as a unit, overcomes the difficulties of serious segregation, poor hot workability, difficult forming and the like of the traditional cast-forged high-temperature alloy ingot due to high alloying degree, and is mainly used for high-temperature bearing rotating parts such as turbine discs, compressor discs, drum shafts, sealing discs, sealing rings, wind guide wheels, turbine disc high-pressure baffles and the like.
The diagnosis method comprises the following steps:
1) the single crystal high temperature alloy is used as a metal matrix material and is fixed well through a matrix clamping control unit.
2) The surface of the metal substrate was subjected to sand blasting, and then the bond coat NiAl coating was sprayed using a supersonic flame, to obtain a 150 μm thick coating.
3) 7YSZ powder with the granularity of 37-69 mu m is adopted, and the powder feeding rate is 3-4 g/min.
4) And starting the plasma generation unit and the jet flow stabilization control unit.
5) Working gas is adjusted to be nitrogen and helium through the jet flow stability control unit, and working current is 2000A.
6) Controlling a mechanical arm in the plasma generating unit, and selecting the spraying distance of a detection end 2-1 for placing a signal acquisition probe unit 2 to be 1200 mm;
7) starting the probe power supply unit 4, recording and displaying the reading, and rechecking the result;
8) controlling the mechanical arm to scan at the speed of 0.4m/s, starting the probe power supply unit 4 again, and recording the result;
9) based on the recorded results, the probe power supply unit 4 calculates parameters such as electron temperature, spatial levitation potential, plasma density, and the like of the position to be diagnosed.
Example 2: YSZ coating sprayed on surface of high-temperature alloy K456
The nickel-based superalloy K465 alloy has high creep resistance, fatigue resistance and high temperature bearing capacity.
The diagnosis method comprises the following steps:
1) a substrate of 8X 200mm was prepared using the high temperature alloy K456 as a metal substrate, and the substrate was fixed by a substrate holding control unit.
2) The surface of the metal substrate was grit blasted and then the bond coat NiCrAlY was spray coated using a supersonic flame to obtain a 150 μm thick coating.
3) 7YSZ powder with the granularity of 1-30 mu m is adopted, and the powder feeding rate is 3-4 g/min.
4) And starting the plasma generation unit and the jet flow stabilization control unit.
5) Adjusting working gases to be nitrogen and helium, working current 2600A and total gas flow 90SLPM through a jet flow stabilization control unit;
6) controlling a mechanical arm in the plasma generating unit, and selecting the spraying distance of a detection end 2-1 for placing a signal acquisition probe unit 2 to be 1500 mm;
7) starting the probe power supply unit 4, recording and displaying the reading, and rechecking the result;
8) controlling the mechanical arm to scan at the speed of 0.4m/s, moving the mechanical arm to the position of 250mm in the radial direction, starting the power supply of the probe again, and recording the result;
9) based on the recorded results, the probe power supply unit 4 calculates parameters such as electron temperature, spatial levitation potential, plasma density, and the like of the position to be diagnosed.
The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
While preferred embodiments of the present invention have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the invention.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.
The present invention provides a contact probe diagnostic device and method for plasma spraying under low vacuum condition, which is described in detail above, and the principle and the implementation mode of the present invention are explained in the present text by applying specific examples, and the description of the above examples is only used to help understanding the method of the present invention and the core idea thereof; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (10)
1. A contact probe diagnostic device for plasma spraying under low vacuum conditions, the device comprising:
the device comprises a signal acquisition probe unit (2) and a high-temperature contact protection unit (3) which are arranged in a low-pressure cabin (1) of a plasma spraying system under the low vacuum condition, wherein the high-temperature contact protection unit (3) is arranged between a plasma jet and the signal acquisition probe unit (2), and a detection end (2-1) of the signal acquisition probe unit (2) passes through the high-temperature contact protection unit (3) and then contacts with the plasma jet in the low-pressure cabin (1) and generates a variable voltage signal along with the parameter change of the plasma jet;
a probe power supply unit (4) arranged outside the low-pressure cabin (1), and an auxiliary line unit (5) used for connecting the probe power supply unit (4) with the output end of the signal acquisition probe unit (2);
the probe power supply unit (4) is used for supplying power to the signal acquisition probe unit (2) through the auxiliary line unit (5) and monitoring the space suspension potential and/or the electronic temperature of the plasma jet in the spraying process according to the changed voltage signal.
2. The device according to claim 1, wherein the high temperature contact protection unit (3) comprises a high temperature resistant alloy substrate and a ceramic coating deposited on the high temperature resistant alloy substrate, the ceramic coating facing the plasma jet and the high temperature resistant alloy substrate facing the signal acquisition probe unit (2), wherein the ceramic coating is used to support the high temperature contact protection unit (3) to operate at 14000K and 6000 m/s.
3. The device according to claim 1, characterized in that the inner wall of the low-pressure cabin (1) is provided with a moving track (6), the bottom of the high-temperature contact protection unit (3) is provided with a slide block, and the slide block is matched with the moving track (6); the moving track (6) and the sliding block are both made of high-temperature-resistant materials, and the high-temperature-resistant materials are used for supporting the moving track (6) and the sliding block to work under the conditions of 14000K and 6000 m/s.
4. An apparatus according to claim 1 or 3, characterized in that the high temperature contact protection unit (3) is movable in the ballast (1) with a radial length of 10-500 mm and an axial length of 100-1800 mm.
5. The device according to claim 1, characterized in that the probing end (2-1) of the signal collecting probe unit (2) has a length of more than 10-50 mm.
6. The device according to claim 1 or 5, characterized in that the probing end (2-1) of the signal acquisition probe unit (2) is made of tungsten, tantalum or molybdenum material.
7. The device according to claim 1, wherein the auxiliary line unit (5) comprises an electric wire (5-1) and a plurality of ceramic rings (5-2), the plurality of ceramic rings (5-2) being fitted over the electric wire (5-1) at a predetermined interval.
8. The device according to claim 1, characterized in that the probe power supply unit (4) comprises a display screen (4-1), the display screen (4-1) being used for displaying and recording the spatial levitation potential and/or the electron temperature of the plasma jet during the spraying process.
9. A method of diagnosing a contact probe for plasma spraying under low vacuum conditions, the method comprising:
determining a position to be diagnosed in a low pressure chamber (1) in a plasma spraying system under low vacuum, connecting a contact probe diagnosis device for plasma spraying under low vacuum according to any one of claims 1 to 8, and placing a detection end (2-1) of the signal acquisition probe unit (2) in the device at the position to be diagnosed;
adjusting the low-pressure cabin (1) to a target vacuum degree, and spraying plasma jet to a metal substrate by using a plasma generator in a plasma spraying system under the low vacuum condition; the detection end (2-1) of the signal acquisition probe unit (2) penetrates through the high-temperature contact protection unit (3) and then contacts with the plasma jet, and a first voltage signal is generated;
starting a probe power supply unit (4) in the device, and recording the first voltage signal corresponding to the position to be diagnosed by using the probe power supply unit (4);
adjusting parameters of the jet plasma jet, starting the probe power supply unit (4) again, and recording the second voltage signal corresponding to the position to be diagnosed by using the probe power supply unit (4);
and calculating and obtaining the spatial suspension potential and/or the electronic temperature of the plasma jet at the position to be diagnosed in the spraying process according to the first voltage signal and the second voltage signal.
10. The method according to claim 9, characterized in that the vacuum degree of the low-pressure cabin (1) is adjusted in the range of 50Pa to 1000 Pa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110914737.4A CN113862604A (en) | 2021-08-10 | 2021-08-10 | Contact probe diagnostic device and method for plasma spraying under low vacuum condition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110914737.4A CN113862604A (en) | 2021-08-10 | 2021-08-10 | Contact probe diagnostic device and method for plasma spraying under low vacuum condition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113862604A true CN113862604A (en) | 2021-12-31 |
Family
ID=78990360
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110914737.4A Pending CN113862604A (en) | 2021-08-10 | 2021-08-10 | Contact probe diagnostic device and method for plasma spraying under low vacuum condition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113862604A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101361176A (en) * | 2005-11-04 | 2009-02-04 | 韩国标准科学研究院 | Plasma diagnostic apparatus and method |
| CN104244555A (en) * | 2014-09-29 | 2014-12-24 | 北京航空航天大学 | Langmuir emitting probe for plasma space potential diagnosing |
| US20150355243A1 (en) * | 2013-01-16 | 2015-12-10 | Universitetet I Oslo | Langmuir probe |
| CN109104805A (en) * | 2018-07-25 | 2018-12-28 | 北京航空航天大学 | Langmuir probe, Langmuir probe diagnostic system and its diagnostic method |
-
2021
- 2021-08-10 CN CN202110914737.4A patent/CN113862604A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101361176A (en) * | 2005-11-04 | 2009-02-04 | 韩国标准科学研究院 | Plasma diagnostic apparatus and method |
| US20150355243A1 (en) * | 2013-01-16 | 2015-12-10 | Universitetet I Oslo | Langmuir probe |
| CN104244555A (en) * | 2014-09-29 | 2014-12-24 | 北京航空航天大学 | Langmuir emitting probe for plasma space potential diagnosing |
| CN109104805A (en) * | 2018-07-25 | 2018-12-28 | 北京航空航天大学 | Langmuir probe, Langmuir probe diagnostic system and its diagnostic method |
Non-Patent Citations (2)
| Title |
|---|
| 毛杰等: "等离子喷涂过程中的等离子射流特性诊断技术", 《材料保护》 * |
| 郭志颖等: "减压直流非转移弧等离子体射流速度的静电探针测量", 《宇航计测技术》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100554911C (en) | By the unique and simple measuring method microstructure change of detection means nondestructively | |
| Fukanuma et al. | In-flight particle velocity measurements with DPV-2000 in cold spray | |
| Fauchais et al. | Heat, mass and momentum transfer in coating formation by plasma spraying | |
| Liu et al. | Low-pressure plasma-induced physical vapor deposition of advanced thermal barrier coatings: microstructures, modelling and mechanisms | |
| CN102667399B (en) | Surface analysis for detecting closed holes, and device | |
| Zavareh et al. | Development and protection evaluation of two new, advanced ceramic composite thermal spray coatings, Al2O3–40TiO2 and Cr3C2–20NiCr on carbon steel petroleum oil piping | |
| Refke et al. | Characterization of LPPS processes under various spray conditions for potential applications | |
| Dolmaire et al. | Benefits of hydrogen in a segmented-anode plasma torch in suspension plasma spraying | |
| CN102409280A (en) | Aluminum oxide ceramic coating with nano crystal structure and preparation method thereof | |
| CN113862604A (en) | Contact probe diagnostic device and method for plasma spraying under low vacuum condition | |
| CN101812657A (en) | Method for preparing ultrahard erosion-resistant amorphous steel coating | |
| Venugopal et al. | Evaluation of arc sprayed coatings for erosion protection of tubes in atmospheric fluidised bed combustion (AFBC) boilers | |
| Zhang et al. | Measurement of specific enthalpy under very low pressure plasma spray condition | |
| Li et al. | Microstructure and property of Al2O3 coating microplasma-sprayed using a novel hollow cathode torch | |
| CN106521393B (en) | A kind of coating production and device based on spark discharge | |
| Li et al. | Effects of spray parameters on the microstructure and property of Al2O3 coatings sprayed by a low power plasma torch with a novel hollow cathode | |
| Wen et al. | The influence of anode inner contour on atmospheric DC plasma spraying process | |
| CN105228327A (en) | Laser Welding aperture plasma electric properties checkout gear and method | |
| ZHOU et al. | Effects of laser scanning welding process on porosity rate of aluminum alloy | |
| CN206368194U (en) | Coating preparation facilities based on spark discharge | |
| Chen et al. | High-Temperature, Wide-Range and Fast-Response Thin Film Anemometer Based on Plasma of Glow Discharge | |
| Fauchais et al. | Wire arc spraying | |
| Marrocco et al. | Comparison of the microstructure of cold sprayed and thermally sprayed IN718 coatings | |
| Yushchenko et al. | Microplasma spraying | |
| Brossa et al. | Plasma spraying—a versatile coating technique |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information |
Inventor after: Guo Hongbo Inventor after: Liu Senhui Inventor after: He Wenting Inventor after: Shi Jia Inventor after: Wei Liangliang Inventor after: Peng Hui Inventor before: Guo Hongbo Inventor before: Liu Senhui Inventor before: He Wenting Inventor before: Shi Jia Inventor before: Wei Liangliang Inventor before: Peng Hui |
|
| CB03 | Change of inventor or designer information |