Method for plating stainless steel protective cover on NdFeB magnet surface with magnetic controlled electrical arc ion

Abstract

The invention provides a method for plating a stainless steel protective layer on surface magnetic control electric arc ions of NdFeB magnet; wherein, the NdFeB magnet is charged after being polished, and the vacuum of 3 multiplied by 10 <-1> to 10<0>Pa is pumped and argon of 15 - 30 Pa is filled in; a direct current supply is connected, and the negative bias voltage of 400 - 600V is imposed between the NdFeB magnet and a vacuum chamber shell, and the surface of porous magnet is pretreated through the bombardment of glow discharge plasma, and oil films and oxidative films are removed from the surface of the magnet for 3 to 5 minutes; arc light power supply is connected, and arc discharge is generated between a striking hook and stainless steel target materials, and the working current of single targets is 40 - 90A, and target material particles evaporated from magnetic control electric arcs are deposited on the surface of the magnet to form uniformly a plated protective layer for 60 to 120minutes; the arc light power supply and the direct current supply are turned off and the temperature is reduced in the argon protection and the polishing is done after the discharging. The method overcomes the defects of not achieving the function of anticorrosion as plating layers can easily strip off with gaps among the plating layers in the wet plating process of an NdFeB substrate.

Description

technical field

[0001] The invention relates to a method for magnetron arc ion plating of a stainless steel protection layer on the surface of an NdFeB magnet, belonging to the technical field of surface protection of porous magnets. Background technique

[0002] Sintered NdFeB permanent magnet materials have attracted much attention for their excellent magnetic properties and high cost performance, and have been widely used in many high-tech fields. Since the sintered NdFeB magnet is sintered by powder metallurgy, the structure is loose, there are a large number of pores on the surface, and the mass distribution is uneven, and the NdFeB itself is composed of multiphase (Nd2Fe14B main phase, Nd-rich Nd-rich phase and Nd1.1Fe4B4 boron-rich phase), there is a large chemical potential difference between the phases, in a humid environment, it is easy to produce intergranular corrosion, which will cause the dissolution of the neodymium-rich phase, boron-rich phase and the main ph...

Examples

Embodiment 1

[0019] The method of magnetically controlled arc ion plating stainless steel protective layer on the surface of NdFeB magnet is realized according to the following steps:

[0020] The first step is to polish the NdFeB magnet and install it in the furnace, and then vacuumize it to about 3×10 -1 Pa, through argon to 30Pa;

[0021] The second step is to turn on the DC power supply, apply a 400-volt negative bias between the NdFeB magnet and the vacuum chamber shell, and purify and activate the surface of the porous magnet through glow ion bombardment to remove the oil film on the surface of the magnet , oxide film, time 5min;

[0022] The third step is to turn on the arc power supply, arc discharge is generated between the arc hook and the chromium-type stainless steel target, the working current of a single target is 40A, and the target particles evaporated by the magnetron arc are deposited on the surface of the magnet to form a uniform coating. Protective layer, time 120min;...

Embodiment 2

[0025] The method of magnetically controlled arc ion plating stainless steel protective layer on the surface of NdFeB magnet, the method steps are the same as above, and the specific parameters are:

[0026] After polishing the NdFeB permanent magnet, install it in the furnace and vacuumize it to about 6×10 -1 Pa, through argon gas to 20Pa; connect the DC power supply, apply a 500-volt negative bias between the NdFeB magnet and the vacuum chamber shell, and purify and activate the surface of the porous magnet by glow ion bombardment, and remove The oil film and oxide film on the surface of the magnet, the time is 5min; then the arc power is turned on, the arc discharge is generated between the arc hook and the nickel-chromium stainless steel target, the single target operating current is 60A, and the target particles evaporated by the magnetron arc are deposited. On the surface of the magnet, a uniformly coated protective layer is formed for 90 minutes; the arc power supply is...

Embodiment 3

[0028] The method of magnetically controlled arc ion plating stainless steel protective layer on the surface of NdFeB magnet, the method steps are the same as above, and the specific parameters are:

[0029] Polish the NdFeB permanent magnet and install it in the furnace, vacuumize it to about 1Pa, pass the argon gas to 30Pa, connect the DC power supply, apply a 600V negative bias voltage between the NdFeB magnet and the vacuum chamber shell, and pass the glow Purify and activate the surface of the porous magnet by photoion bombardment, remove the oil film and oxide film on the surface of the magnet for 4 minutes; The working current is 80A, and the time is 60min; the arc power supply is turned off, the DC power supply is turned off, the temperature is lowered under the protection of argon gas, and the polishing treatment is carried out after being out of the furnace.

technical field

[0001] The invention relates to a method for magnetron arc ion plating of a stainless steel protection layer on the surface of an NdFeB magnet, belonging to the technical field of surface protection of porous magnets. Background technique

[0002] Sintered NdFeB permanent magnet materials have attracted much attention for their excellent magnetic properties and high cost performance, and have been widely used in many high-tech fields. Since the sintered NdFeB magnet is sintered by powder metallurgy, the structure is loose, there are a large number of pores on the surface, and the mass distribution is uneven, and the NdFeB itself is composed of multiphase (Nd2Fe14B main phase, Nd-rich Nd-rich phase and Nd1.1Fe4B4 boron-rich phase), there is a large chemical potential difference between the phases, in a humid environment, it is easy to produce intergranular corrosion, which will cause the dissolution of the neodymium-rich phase, boron-rich phase and the main ph...

Examples

Embodiment 1

[0019] The method of magnetically controlled arc ion plating stainless steel protective layer on the surface of NdFeB magnet is realized according to the following steps:

[0020] The first step is to polish the NdFeB magnet and install it in the furnace, and then vacuumize it to about 3×10 -1 Pa, through argon to 30Pa;

[0021] The second step is to turn on the DC power supply, apply a 400-volt negative bias between the NdFeB magnet and the vacuum chamber shell, and purify and activate the surface of the porous magnet through glow ion bombardment to remove the oil film on the surface of the magnet , oxide film, time 5min;

[0022] The third step is to turn on the arc power supply, arc discharge is generated between the arc hook and the chromium-type stainless steel target, the working current of a single target is 40A, and the target particles evaporated by the magnetron arc are deposited on the surface of the magnet to form a uniform coating. Protective layer, time 120min;...

Embodiment 2

[0025] The method of magnetically controlled arc ion plating stainless steel protective layer on the surface of NdFeB magnet, the method steps are the same as above, and the specific parameters are:

[0026] After polishing the NdFeB permanent magnet, install it in the furnace and vacuumize it to about 6×10 -1 Pa, through argon gas to 20Pa; connect the DC power supply, apply a 500-volt negative bias between the NdFeB magnet and the vacuum chamber shell, and purify and activate the surface of the porous magnet by glow ion bombardment, and remove The oil film and oxide film on the surface of the magnet, the time is 5min; then the arc power is turned on, the arc discharge is generated between the arc hook and the nickel-chromium stainless steel target, the single target operating current is 60A, and the target particles evaporated by the magnetron arc are deposited. On the surface of the magnet, a uniformly coated protective layer is formed for 90 minutes; the arc power supply is...

Embodiment 3

[0028] The method of magnetically controlled arc ion plating stainless steel protective layer on the surface of NdFeB magnet, the method steps are the same as above, and the specific parameters are:

[0029] Polish the NdFeB permanent magnet and install it in the furnace, vacuumize it to about 1Pa, pass the argon gas to 30Pa, connect the DC power supply, apply a 600V negative bias voltage between the NdFeB magnet and the vacuum chamber shell, and pass the glow Purify and activate the surface of the porous magnet by photoion bombardment, remove the oil film and oxide film on the surface of the magnet for 4 minutes; The working current is 80A, and the time is 60min; the arc power supply is turned off, the DC power supply is turned off, the temperature is lowered under the protection of argon gas, and the polishing treatment is carried out after being out of the furnace.