A kind of soft metal powder and hard particles prepare the method and the device of compound coating
Technical field
The present invention relates to the technology of preparing of metal composite coating, specifically is exactly method and device that a kind of soft metal powder and hard particles prepare compound coating.
Background technology
In existing technology, there is several different methods to prepare metal and ceramic composite coating, but always there is a lot of problems, see " pottery " magazine fourth phase in 2008 " present Research of cermet composite coating technology of preparing " for details, when preparing metal-ceramic coating with hot spray process, the spray material utilization ratio is low, be difficult to prepare the bigger coated material of thickness etc.Spreading its shortcoming of high temperature synthetic technology is to be subjected to the restriction of starting material system selection bigger in using, and the dense coating of the big thickness of preparation is difficulty relatively.The one-time investment of laser melting and coating technique equipment is big, and the running cost height especially during the big area cladding, must be taked the lap joint process measure because spot size is little, has increased the probability that metallurgical imperfection produces.Raw materials used majority is an organic compound in sol-gel method, and cost is high and some is harmful, and the treatment time is long, and goods are easy to crack etc.When the vacuum liquid-phase sintering legal system is equipped with the metal-ceramic compound coating, adopt slip coating or spraying coating process usually, the slurry process coating is not owing to fine and close, so the energy force rate powder method coating of resistance to fracture is low.Prepare the problem that also there is the bonding force difference in some soft metals (as fine aluminium coating etc.) with the aerodynamic force spraying method.
Summary of the invention
The object of the present invention is to provide a kind of soft metal powder and hard particles to prepare the method and the isolated plant thereof of compound coating, this method can prepare the compound coating of different components ratio, and the hard particles disperse is distributed in the coating of soft metal, can on the various material base material, directly prepare coating, and thickness is unrestricted; This apparatus structure is simple, easy to operate.
For achieving the above object, technical scheme of the present invention:
A kind of soft metal powder and hard particles prepare the method for compound coating, adopt the aerodynamic force spraying technology, use soft metal powder and hard particles to mix; The source of the gas pressurized gas divides two-way, and one the tunnel enters powder feeder, as carrier powder is introduced superonic flow nozzzle; Another road enters well heater, gas is gone into superonic flow nozzzle through preheating is laggard, inlet mouth at superonic flow nozzzle, two-way gas mixes the gas-solid two-phase flow of formation at inlet mouth, two-phase flow accelerates to velocity of sound in the constriction of superonic flow nozzzle, then continue the acceleration of expanding at the expansion of superonic flow nozzzle by throat, two-phase flow reaches supersonic speed in the exit of nozzle, gas-solid two-phase flow is sprayed to base material, powder deposition at substrate surface, is formed the coating that soft metal powder and hard particles two-phase even dispersion distribute; Its processing parameter is: jet length 5~50mm; Gas pressure intensity 0.5~5.0MPa; In the two-way pressurized gas, the gas temperature that enters powder feeder is a room temperature, and the gas temperature that enters after the heater heats is 150~700 ℃, and the air flow rate of two-way pressurized gas is 10~30g/s, and the granularity of soft metal powder or hard particles is 1~300 μ m.
In the above-mentioned processing parameter, preferable range is as follows: jet length 15~45mm; Gas pressure intensity 1.0~3.0MPa; In the two-way pressurized gas, the gas temperature that enters powder feeder is a room temperature, and the gas temperature that enters after the heater heats is 180~500 ℃, and the air flow rate of two-way pressurized gas is 15~25g/s, and the granularity of soft metal powder or hard particles is 10~50 μ m.
Used powder is the powder of pure soft metal or powdered alloy and the preparation of hard particles employing mechanically mixing method.
Described pure soft metal powder is Al, Cu, Ag, Sn, Zn or Pb; Described powdered alloy is aluminium alloy, copper alloy or terne metal etc.
Described hard particles is Al
2O
3, SnO
2, SiO
2, InO
2Or diamond.
Described gas is air, nitrogen or helium.
Among the present invention, the part by weight of soft metal powder and hard particles is for to mix from 1: 1 to arbitrary proportion the soft metal powder, the part by weight that is soft metal powder and hard particles is 1: (0~1, and be not 0), the preferred weight ratio of soft metal powder and hard particles is (1~100): 1.
A kind of soft metal powder and hard particles prepare the isolated plant of the method for compound coating, this device is provided with high-pressure air source, well heater, powder feeder, the superonic flow nozzzle that links to each other with inlet pipe, the inlet pipe of described connection high-pressure air source is connected with superonic flow nozzzle with well heater through powder feeder respectively, and the pipe section that places well heater is a helix structure.
Among the present invention, superonic flow nozzzle is made up of contraction section, throat and expansion segment three parts, and the sectional area of the sectional area of nozzle inlet mouth, throat, air outlet must meet certain ratio, can reach supersonic speed to guarantee pressurized gas by after the nozzle.Superonic flow nozzzle of the present invention adopts disclosed patent application, and the denomination of invention of this patent application is a cold air driven spray painter, and application number is 01128130.8, and publication number is CN1403210A.
Compared with prior art, the present invention has the following advantages:
1. the present invention adopts the aerodynamic force spraying technology, only by mechanical uniform mixing powder, just can utilize high velocity air that soft metal powder and hard particles directly are sprayed at workpiece surface, by parameters such as control spray angles, make powder deposition on workpiece, form the NEW TYPE OF COMPOSITE coating that even dispersion distributes, can realize that low-temperature and high-speed deposition soft metal powder and hard particles form compound coating, have changed the way that traditional preparation method must be heated to melted state earlier.
2. the present invention can directly prepare soft metal powder and hard particles blended compound coating in surfaces of various materials, for example prepares wear-resisting and conductive coating etc.
3. the present invention can adopt soft metal powder and hard particles mechanically mixing powder; do not need the coating of powder to handle as raw material; the compound coating that therefore can prepare the arbitrary element ratio easily; that is to say that soft metal powder and hard particles content can be arbitrary value, solved traditional method restricted problem on some constituent content.
4. the compound coating process of preparation soft metal powder of the present invention and hard particles can have been avoided the harm to operator of some toxic metal such as lead, more compliance with environmental protection requirements being lower than fusing point even can at room temperature carrying out.
5. the soft metal powder of the method for the invention preparation has composition with the hard particles compound coating and is evenly distributed the advantage that microstructure is tiny mutually.
6. the inventive method is simple, cost is low, efficient is high, and it is simple in structure, practical, easy to operate to prepare its isolated plant of multiple compound coating.
7. the used powder of the present invention is soft metal powder and hard particles mixed powder, and these powder systems comprise: abrasion-resistant material, and as Al-Al
2O
3, Cu-C (diamond) etc.; Electrical material, as with Ag, Cu, Al as matrix, InO
2, SnO
2Deng as the disperse phase element, form the structure of conduction and heat conduction, to improve the intensity and the high conductivity of material.
Description of drawings
Fig. 1 is apparatus of the present invention synoptic diagram.Among the figure, 1 inlet pipe; 2 powder feeders; 3 well heaters; 4 superonic flow nozzzles; 5 base materials; 6 Gas controllers.
Fig. 2 is embodiment 1 a coating SEM microstructure section photo.
Embodiment
As shown in Figure 1, the preparation method's of soft metal powder and hard particles compound coating isolated plant, have the high-pressure air source that links to each other with inlet pipe 1, powder feeder 2, well heater 3, superonic flow nozzzle 4, Gas controller 6 etc., the inlet pipe 1 that connects high-pressure air source is connected with Gas controller 6, Gas controller 6 is connected by pipeline with powder feeder 2 and well heater 3 respectively, powder feeder 2 is connected with superonic flow nozzzle 4 by pipeline respectively with well heater 3, the pipe section that places well heater 3 is a helix structure, and base material 5 is relative with superonic flow nozzzle 4 outlets.
The present invention adopts the aerodynamic force spraying technology, use mechanical uniform mixing soft metal powder and hard particles, high pressure gas enter powder feeder 2 and well heater 3 through inlet pipe 1, the portion gas that enters powder feeder 2 carries powder by powder feeder and is mixed into gas-solid two-phase flow in the ingress of superonic flow nozzzle and the preheating gas of process well heater 3, through accelerator, two-phase flow reaches the supersonic speed state in the exit of nozzle to gas-solid two-phase flow in superonic flow nozzzle.Metallic particles in the two-phase flow has very high kinetic energy, is adhered to substrate surface taking place in the process of bump serious viscous deformation to take place with substrate surface, and follow-up kinetic energy particle repeats this process and forms alloy or coating.Thereby, utilize high velocity air with powder deposition at substrate surface, form the compound coating of even dispersion.
Embodiment 1
The soft metal powder and the hard particles compound coating of present embodiment preparation are anti-scuff coating Al-Al
2O
3System, used powder are the mixed powder of fine aluminium and aluminum oxide, and the part by weight of fine aluminium and aluminum oxide is 3: 1, and base material is a magnesium alloy.Spraying parameter is as follows: jet length 10mm; Gas pressure intensity 1.9MPa; In the two-way pressurized gas, the gas temperature that enters powder feeder is a room temperature, and the gas temperature that enters after the heater heats is 220 ℃; The air flow rate of two-way pressurized gas is 15g/s; The powder size of soft metal powder and hard particles is 5~50 microns.The result has obtained Al-Al
2O
3Coating, through scanning electron microscopic observation, Al-Al
2O
3Be evenly distributed mutually, do not have poly-partially phenomenon and occur, see Fig. 2.
Embodiment 2
Difference from Example 1 is:
Soft metal powder and the hard particles compound coating wear-resistant coating copper and the diamond coatings of present embodiment preparation, No. 45 steel are as matrix, copper and diamond powder are coated material, copper and adamantine part by weight 10: 1, and spraying parameter is as follows: jet length 20mm; Gas pressure intensity 2.0MPa; In the two-way pressurized gas, the gas temperature that enters powder feeder is a room temperature, and the gas temperature that enters after the heater heats is 350 ℃; The air flow rate of two-way pressurized gas is 30g/s; The powder mean particle sizes of soft metal powder and hard particles is 50 microns.The result has obtained copper and diamond coatings, and through scanning electron microscopic observation, copper and diamond coatings two-phase are evenly distributed compact structure.
Embodiment 3
Difference from Example 1 is:
The soft metal powder and the hard particles compound coating of present embodiment preparation are high conductive coating Ag-SnO
2Coating, Ag and SnO
2Mixed powder, Ag and SnO
2Part by weight 20: 1, base material is a copper.Spraying parameter is as follows: jet length 40mm; Gas pressure intensity 1.8MPa; In the two-way pressurized gas, the gas temperature that enters powder feeder is a room temperature, and the gas temperature that enters after the heater heats is 500 ℃; The air flow rate of two-way pressurized gas is 30g/s; The powder mean particle sizes of soft metal powder and hard particles is 5 microns.The result has obtained Ag-SnO
2Coating, through scanning electron microscopic observation, Ag-SnO
2Two-phase is evenly distributed, and does not have poly-partially phenomenon and occurs.
Embodiment 4
Difference from Example 1 is:
The soft metal powder and the hard particles compound coating of present embodiment preparation are Cu-InO
2Coating, Cu and InO
2Mixed powder, Cu and InO
2Part by weight 5: 1, base material is an aluminium.Spraying parameter is as follows: jet length 15mm; Gas pressure intensity 3.0MPa; In the two-way pressurized gas, the gas temperature that enters powder feeder is a room temperature, and the gas temperature that enters after the heater heats is 330 ℃; The air flow rate of two-way pressurized gas is 20g/s; The powder mean particle sizes of soft metal powder and hard particles is 50 microns.The result has obtained Cu-InO
2Coating, through scanning electron microscopic observation, Cu-InO
2Two-phase is evenly distributed, and does not have poly-partially phenomenon and occurs.
Embodiment result shows that the present invention can effectively improve Bond Strength of Coating by using the method for mixing hard particles in the soft metal, the preparation thick coating, and the preparation coating is with low cost, simultaneously the recyclable utilization of powder.The hardness etc. that can effectively improve Bond Strength of Coating and increase coating by the method for use mixing hard particles has plurality of advantages.This compound coating has a wide range of applications in the following aspects.
1. abrasion-resistant material is that compound coating has application prospect most and obtained the field of widespread use, this class material is usually by two phase composites, hard particles carry load wherein, softer metal is uniformly distributed in the matrix as antifriction material, the wide range of this class material is general, such as: copper diamond composite coating, aluminum aluminum oxide compound coating or the like.
2. in compound coating, contain a kind of such as Ag, Cu and Al, SnO as matrix
2,InO
2Deng as complex element, form the structure of conduction and heat conduction.This compound coating can improve the conduction and the capacity of heat transmission, increases the intensity of coating, improves coating's adhesion.
In addition, soft metal powder and hard particles prepare compound coating and also thirst for using widely other all many-sided acquisition.