Patent Application
20170044673
The present invention relates to a material surface wear-resistant coating and preparation thereof, and particularly to a Co3W3C fish-bone-shape hard-phase reinforced Fe-based wear-resistant coating and method for preparing the same.
During use of a mechanical part, most of the wear occurs on the surface part of a workpiece, and especially in a severe working environment, e.g., high corrosion, high friction, high temperature and high pressure and the like, the wear failure of the mechanical part is particularly severe. Therefore, the surface of the mechanical part that has a friction pair is required to have high hardness and wear resistance during use. The surface engineering technology can make a wear-resistant coating with superior performance. The coating material is usually a composite material, and the reinforced phase mainly is carbide, boride and nitride with high hardness and wear resistance. Co3W3C fish-bone-shape hard phase does not exist in the reinforced phase of the current wear-resistance coating and is not used as the reinforced phase of the wear-resistant coating.
The present invention is aimed to provide an Co3W3C fish-bone-shape hard-phase reinforced Fe-based wear-resistant coating and preparation thereof, which has a simple and convenient operation process and a cladding layer that is uneasy to break off.
The technical solution for realizing the purpose of the present invention is as follows: The wear-resistant coating and preparation method thereof: use a plasma cladding process to clad the Fe-based WC alloy powder on the surface of a metal matrix to form a wear-resistant high hardness coating with fish-bone-shape Co3W3C as the reinforced phase;
The Fe-based WC mixed alloy powder has the following components in weight percentage: C: 1.89-3.77%, Cr: 5.4-11.7%, Ni: 3.3-7.15%, W: 28.81-57.83%, Co: 4.2-8.4%, Si: 0.03-0.065%, and the remaining is Fe;
The plasma cladding process has the following specific steps:
(1) Pre-treatment of the matrix:
Polishing the surface of the matrix to remove an oxide layer, placing the treated matrix on a plasma cladding working table, and adjusting its position;
(2) Pre-treatment of the alloy powder:
Screening the WC powder with granularity of 280-320 meshes and the Fe-based alloy powder of 100-200 meshes, preparing the Fe-based WC mixed alloy powder with the mentioned weight percentage, putting in a stirrer to stir for 50-60 min, putting in a drying oven to heat at 150° C., and putting in a plasma cladding machine after finishing the above pre-treatments;
(3) Plasma cladding:
The plasma cladding process includes the following technical parameters: A working current of 135-145 A, a working voltage of 11-12 V, powder feeding gas and protecting gas are argon gas, powder feeding gas pressure of 280-300 MPa, protecting gas pressure of 700-800 MPa, distance from a nozzle to the surface of the matrix is 10 mm, and a scanning speed of 80 mm/min.
(4) Treatment of cladding layer:
After finishing the plasma cladding process, turning off the plasma cladding machine, cutting the side and the front of the cladding layer, grinding and polishing, and fish-bone-shape hard phase can be observed under an optical microscope and an electron microscope; in conjunction with the X ray diffraction analysis result, the hard phase is identified as Co3W3C, which exhibits high performance in a hardness test and a wear resistance test.
The beneficial effects: due to the above-mentioned solution, the metallurgical bonding performance of the cladding layer obtained using the plasma cladding technology and the matrix material is superior, the operation process is simple and convenient, and the cost of equipment is low. The plasma cladding process is used to prepare Fe-based WC alloy powder to obtain the Co3W3C fish-bone-shape hard-phase reinforced Fe-based wear-resistant coating and preparation method thereof, where the reinforced phase is Co3W3C fish-bone-shape carbide, the carbide has high hardness (micro hardness HV=888−1097) and high wear resistance. The following feature is obtained: the cladding layer with the reinforced phase of fish-bone-shape hard phase Co3W3C has high hardness and high wear resistance; and the cladding layer is uneasy to break off. Therefore, the present invention has high application value and innovation significance.
The present invention is advantaged in:
(1) The plasma cladding process is simple, the equipment is convenient to operate, the economic benefit is high, and the process can be widely used for surface reinforcement of a precision parts.
(2) Adopting the above process scheme, the bonding performance of the resulting cladding layer and the matrix is superior, the optimal performance matching between the ceramic phase of the cladding layer and the matrix can be realized, and the comprehensive physical property of the matrix structure is greatly improved.
(3) The fish-bone-shape reinforced phase Co3W3C has features of high hardness and high wear resistance, improves the hardness of the cladding layer, reduces the wear of the matrix structure as the framework of the cladding layer in friction, and efficiently improves the use value of the matrix.
The specific embodiment of the present invention is further described below in conjunction with the accompanying drawings:
The wear-resistant coating and preparation method thereof of the present invention: use a plasma cladding process to clad the Fe-based WC alloy powder on the surface of a metal matrix to form a wear-resistant high hardness coating with fish-bone-shape Co3W3C as the reinforcement phase;
The Fe-based WC mixed alloy powder has the following components in weight percentage: C: 1.89-3.77%, Cr: 5.4-11.7%, Ni: 3.3-7.15%, W: 28.81-57.83%, Co: 4.2-8.4%, Si: 0.03-0.065%, and the remaining is Fe;
The plasma cladding process has the following specific steps:
(1) Pre-treatment of the matrix:
Polishing the surface of the matrix to remove oxide layer, placing the treated matrix on a plasma cladding working table, and adjusting its position;
(2) Pre-treatment of the alloy powder:
Screening the WC powder with granularity of 280-320 meshes and the Fe-based alloy powder of 100-200 meshes, preparing the Fe-based WC mixed alloy powder with the mentioned weight percentage, putting in a stirrer to stir for 50-60 min, putting in a drying oven to heat at 150° C., and putting in a plasma cladding machine after finishing the above pre-treatments;
(3) Plasma cladding:
The plasma cladding process includes the following technical parameters: A working current of 135-145 A, a working voltage of 11-12 V, powder feeding gas and protecting gas are argon gas, powder feeding gas pressure of 280-300 MPa, protecting gas pressure of 700-800 MPa, distance from a nozzle to the surface of the matrix is 10 mm, and a scanning speed of 80 mm/min.
(4) Treatment of a cladding layer:
After finishing the plasma cladding process, turning off the plasma cladding machine, cutting the side and the front of the cladding layer, grinding and polishing, and fish-bone-shape hard phase is observed under optical microscope and electron microscope; in conjunction with the X ray diffraction analysis result, the hard phase is identified as the Co3W3C, which exhibits high performance in a hardness test and a wear resistance test.
The surface of the matrix is polished to remove oxide layer, the treated matrix is placed on a plasma cladding working table, and its position is adjusted.
The WC powder with granularity of 280-320 meshes and the Fe-based alloy powder of 100-200 meshes are screened to prepare the Fe-based WC mixed alloy powder including the following components in weight percentage: C: 3.24%, Cr: 7.2%, Ni: 4.4%, W: 49.56%, Co: 7.2%, Si: 0.04%, and the remaining is Fe. The powder is subjected to pre-treatment, put in a stirrer to stir for 50-60 min, put in a drying oven to heat at 150° C., and put in a powder feeder. The cladding process includes: A working current of 140 A, a working voltage of 11 V, powder feeding gas and protecting gas are argon gas, a powder feeding gas pressure of 300 MPa, a protecting gas pressure of 800 MPa, distance from a nozzle to the surface of the matrix is 10 mm, and a scanning speed of 80 mm/min. The plasma cladding machine is turned off after finishing the cladding, the workpiece is naturally cooled to room temperature in the air.
Mutual-rubbing test is performed on an M-200 wear testing machine for the prepared Co3W3C fish-bone-shape hard-phase reinforced Fe-based wear-resistant coating with a wear time of 40 min and a wear amount of 0.008 g, while under the same conditions, Q235 steel has a wear amount of 0.1996 g, the wear resistance is significantly improved, the highest hardness value is up to 946 HV, and the hardness value is also significantly improved.
In
The pre-treatment process of the matrix is kept the same as that of Example 1, and the prepared Fe-based WC mixed alloy powder includes the following components in weight percentage: C: 3.77%, Cr: 5.4%, Ni: 3.3%, W: 57.83%, Co: 8.4%, Si: 0.03%, and the remaining is Fe. The process parameters of the plasma cladding are the same as those of Example 1, and a cladding layer with a superior performance can be obtained.
Mutual-rubbing test is performed on the M-200 wear testing machine for the prepared Co3W3C fish-bone-shape hard-phase reinforced Fe-based wear-resistant coating with a wear time of 40 min, a wear amount of 0.0032 g and a very superior wear resistance.
The pre-treatment process of the matrix is kept the same as that of Example 1, and the prepared Fe-based WC mixed alloy powder includes the following components in weight percentage: C: 1.89%, Cr: 11.7%, Ni: 7.15%, W: 28.81%, Co: 4.2%, Si: 0.065%, and the remaining is Fe. The process parameters of the plasma cladding are the same as those of Example 1, and a cladding layer with a superior performance can be obtained.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201410610715.9 | Nov 2014 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2015/086199 | 8/6/2015 | WO | 00 |
