Method for forming aluminum coating on surface of neodymium iron boron magnet

Abstract

The invention relates to a method for forming an aluminum coating on the surface of a neodymium iron boron magnet and belongs to the technical field of magnet surface treatment. An adopted mechanical aluminum-plating process comprises the following steps of: colliding an impacting medium having aluminum coating powder on the surface thereof with the surface of a plated piece under an action of external mechanical vibration, thereby transferring the aluminum coating powder from the surface of the impacting medium to the surface of the plated piece; heating and solidifying the plated piece; and finally, forming a corrosion-resistance coating on the surface of the plated piece. The method provided by the invention has the advantages that the process is simpler and has a shorter time, the consumption of resources such as water, electricity and the like is low, and the raw materials used in the method, such as aluminum, epoxy resins and the like are low in costs, so that the total cost is greatly lowered.

Description

technical field

[0001] The invention belongs to the technical field of magnet surface treatment, and in particular provides a method for forming an aluminum coating on the surface of a neodymium-iron-boron (NdFeB) magnet. The final formed coating has good corrosion resistance and has no magnetic shielding effect . Background technique

[0002] Neodymium iron boron (NdFeB) permanent magnet material is a functional material with a wide range of applications, and has played an important role in the fields of motors, communications, IT, and wind power generation. NdFeB magnets have a multi-phase structure, and the problem of intergranular corrosion must be overcome by its surface protection. Since surface protection is the last link in magnet production, the quality of electroplating will directly affect the final quality of products. Electroplating technology is NdFeB The most critical technology in the production technology of boron products.

[0003] At present, the surface...

Examples

Embodiment 1

[0035] Take 1 kg of 5*3.5*2mm NdFeB magnet workpiece, chamfer it in the chamfering machine, and then perform rolling sandblasting in the sandblasting machine for 20 minutes. After the sample was taken out, it was simply cleaned, soaked in the phosphating solution for 30s, and then dried.

[0036] On the other hand, 30 kg of steel balls with a diameter of 1.5 mm were put into the vibration container. Weigh out 12g of epoxy resin and 28g of aluminum powder with an average particle size of 28μm with a balance, and mix them evenly. Start the power supply, and when the vibrating container and steel balls are in a vibrating state, slowly put in the mixed powder of epoxy resin and aluminum, and finally put in all of them. Continue to vibrate for about half an hour until the mixed powder is mixed with steel balls.

[0037] Use a balance to measure out 30g of acrylic resin and 180g of thinner (its composition is as above), pour into an empty container and mix and stir until the acryl...

Embodiment 2

[0041] Take 1 kg of 5*3.5*2mm NdFeB magnet workpiece, chamfer, sandblast, and phosphate according to the method in Example 1.

[0042] On the other hand, 40 kg of steel balls with a diameter of 1.5 mm were put into the vibration container. Weigh 28g of epoxy resin and 28g of aluminum powder with an average particle diameter of 10 microns with a balance, and mix them uniformly. According to the method in Example 1, the mixed powder and steel balls were mixed evenly.

[0043] In the same manner as in Example 1, a liquid resin solution was formulated and mechanically plated and baked for curing. Repeat the treatment process 3 times to finally obtain the aluminum powder coating.

[0044] The average thickness of the coating is about 15 microns, and it does not rust for 120 hours in the SST test, and does not rust for 48 hours in the PCT test.

Embodiment 3

[0046] Take 1 kg of 5*3.5*2mm NdFeB magnet workpiece, chamfer, sandblast, and phosphate according to the method in Example 1.

[0047] Put 50 kg of steel balls with a diameter of 0.8 mm into the vibrating container. Weigh 84g of epoxy resin and 28g of aluminum powder with an average particle diameter of 28 microns with a balance, and mix them uniformly. Mix the mixed powder and steel balls according to the method in Example 1.

[0048] Measure 20g of acrylic resin and 200g of thinner with a balance, mix and prepare the liquid resin in the same manner as in Example 1, and coat the magnet workpiece.

[0049] After performing mechanical plating in the same manner as in Example 1, bake in an oven at a temperature of 160° C. for half an hour. Carry out the same treatment process as above three times to the magnet workpiece, and finally obtain the aluminum powder coating.

[0050] The average thickness of the coating is about 10 microns. After the SST test, there is no rust in 72...

technical field

[0001] The invention belongs to the technical field of magnet surface treatment, and in particular provides a method for forming an aluminum coating on the surface of a neodymium-iron-boron (NdFeB) magnet. The final formed coating has good corrosion resistance and has no magnetic shielding effect . Background technique

[0002] Neodymium iron boron (NdFeB) permanent magnet material is a functional material with a wide range of applications, and has played an important role in the fields of motors, communications, IT, and wind power generation. NdFeB magnets have a multi-phase structure, and the problem of intergranular corrosion must be overcome by its surface protection. Since surface protection is the last link in magnet production, the quality of electroplating will directly affect the final quality of products. Electroplating technology is NdFeB The most critical technology in the production technology of boron products.

[0003] At present, the surface...

Examples

Embodiment 1

[0035] Take 1 kg of 5*3.5*2mm NdFeB magnet workpiece, chamfer it in the chamfering machine, and then perform rolling sandblasting in the sandblasting machine for 20 minutes. After the sample was taken out, it was simply cleaned, soaked in the phosphating solution for 30s, and then dried.

[0036] On the other hand, 30 kg of steel balls with a diameter of 1.5 mm were put into the vibration container. Weigh out 12g of epoxy resin and 28g of aluminum powder with an average particle size of 28μm with a balance, and mix them evenly. Start the power supply, and when the vibrating container and steel balls are in a vibrating state, slowly put in the mixed powder of epoxy resin and aluminum, and finally put in all of them. Continue to vibrate for about half an hour until the mixed powder is mixed with steel balls.

[0037] Use a balance to measure out 30g of acrylic resin and 180g of thinner (its composition is as above), pour into an empty container and mix and stir until the acryl...

Embodiment 2

[0041] Take 1 kg of 5*3.5*2mm NdFeB magnet workpiece, chamfer, sandblast, and phosphate according to the method in Example 1.

[0042] On the other hand, 40 kg of steel balls with a diameter of 1.5 mm were put into the vibration container. Weigh 28g of epoxy resin and 28g of aluminum powder with an average particle diameter of 10 microns with a balance, and mix them uniformly. According to the method in Example 1, the mixed powder and steel balls were mixed evenly.

[0043] In the same manner as in Example 1, a liquid resin solution was formulated and mechanically plated and baked for curing. Repeat the treatment process 3 times to finally obtain the aluminum powder coating.

[0044] The average thickness of the coating is about 15 microns, and it does not rust for 120 hours in the SST test, and does not rust for 48 hours in the PCT test.

Embodiment 3

[0046] Take 1 kg of 5*3.5*2mm NdFeB magnet workpiece, chamfer, sandblast, and phosphate according to the method in Example 1.

[0047] Put 50 kg of steel balls with a diameter of 0.8 mm into the vibrating container. Weigh 84g of epoxy resin and 28g of aluminum powder with an average particle diameter of 28 microns with a balance, and mix them uniformly. Mix the mixed powder and steel balls according to the method in Example 1.

[0048] Measure 20g of acrylic resin and 200g of thinner with a balance, mix and prepare the liquid resin in the same manner as in Example 1, and coat the magnet workpiece.

[0049] After performing mechanical plating in the same manner as in Example 1, bake in an oven at a temperature of 160° C. for half an hour. Carry out the same treatment process as above three times to the magnet workpiece, and finally obtain the aluminum powder coating.

[0050] The average thickness of the coating is about 10 microns. After the SST test, there is no rust in 72...

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