Metal-based/diamond laser composite coating and preparation method thereof

• US 9,945,034 B2
• Filed: 07/01/2014
• Issued: 04/17/2018
• Est. Priority Date: 06/18/2014
• Status: Active Grant

• Current Assignee: Hangzhou Bohua Laser Technology Co., Ltd., Zhejiang University Of Technology (Province of Zhejiang)
• Original Assignee: Hangzhou Bohua Laser Technology Co., Ltd., Zhejiang University Of Technology (Province of Zhejiang)
• Inventors: Yao, Jianhua, Li, Bo, Chen, Zhijun, Zhang, Qunli, Hu, Xiaodong, Dong, Gang, Wu, Guolong, Wang, Liang, Kovalenko, Volodymyr
• Primary Examiner(s): Turocy, David P
• Assistant Examiner(s): Mayy, Mohammad
• Application Number:
  US15/301,718
• Publication Number:
  US 20170145568A1
• Time in Patent Office: 1,386 Days
• CPC Class Codes: B05B 3/00 Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements
• CPC Class Codes: B23K 26/00 Working by laser beam, e.g. welding, cutting or boring
• CPC Class Codes: C23C 24/04 Impact or kinetic deposition of particles
• CPC Class Codes: C23C 24/10 with intermediate formation of a liquid phase in the layer

Abstract

A metal-based/diamond laser composite coating preparation method includes: first selecting high-hardness metal powder and diamond powder of a proper grain size and shape; then uniformly mixing the high-hardness metal powder and diamond powder via a ball-milling method; and finally preparing a composite coating on a substrate by synchronously combining laser texturing technology, laser thermal treatment technology and cold spraying technology. The thickness of the composite coating is greater than 1 mm, and the volume content of diamond in the coating is greater than 45%. A metal-based/diamond laser composite coating is also provided.

Claims

1. A preparation method of a metal-based/diamond laser composite coating, comprising steps as follows:

1) uniformly mixing a high-hardness metal powder and a diamond powder to form a composite powder via a ball-milling method;

a hardness of the high-hardness metal powder is greater than 50 HRC, a shape of the high-hardness metal powder is spherical or spherical-like, a granularity of the high-hardness metal powder is 10 μ

m to 20 μ

m;

the diamond powder is in an irregular shape, and has a granularity of 30 μ

m to 50 μ

m;

2) reducing the composite powder being, which has been ball milled, in a reduction furnace;

3) performing a pre-treatment on a substrate;

4) performing a treatment on a surface of the substrate by utilizing a texturing technology of a pulse laser, in order to increase a roughness of the surface;

utilizing a cold spraying method assisted with a continuous laser to synchronously deposit a high-hardness metal-based/diamond composite coating on the substrate treated by the pulse laser texturing, wherein, a distance, at which a pulse laser speckle is in front of a sprayed powder speckle in step

     4), is less than 15 mm, a continuous laser speckle and the sprayed powder speckle is overlapped, an angle between a continuous laser beam and a cold spraying nozzle is 20°

to 30°

, the pulse laser speckle, the continuous laser speckle and the sprayed powder speckle keep moving synchronously at a moving velocity of 30 mm/s to 50 mm/s.

2. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein the high-hardness metal powder is one or more of a nickel-based powder and a cobalt-based powder.

3. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein utilizing a planetary mixing in the ball-milling method in the step 1), a ball/powder ratio is 30:

1 to 100;

1, a ball-milling rotational speed is 200 r/min to 600 r/min, a ball-milling time is 2 h to 24 h, a ball-milling atmosphere is nitrogen gas or argon gas.

4. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein utilizing a vibratory mixing in the ball-milling method in the step 1), a ball/powder ratio is 30:

1 to 100;

1, a vibration frequency is 1200 r/min, a ball-milling time is 20 min to 60 min, a ball-milling atmosphere is nitrogen gas or argon gas.

5. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein the composite powder is reduced in a muffle furnace, a reducing atmosphere is hydrogen gas, a reducing time is 30 min, a reducing temperature is 200°

C. to 400°

C.

6. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein the substrate is an iron-based material with an arbitrary shape, a method of the pre-treatment on the substrate is a supersonic surface cleaning.

7. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein an energy density of the pulse laser is 104 W/cm² to 108 W/cm², a pulse width is 0.5 ms to 2 ms, a wavelength is 1460 nm to 1610 nm, an energy density of the continuous laser of a semiconductor is 3×

10⁵ W/cm² to 5×

10⁵ W/cm², a wavelength is 960 nm to 1064 nm, an output power of the continuous laser of the semiconductor is adjusted in real time through a closed loop feedback temperature control mode, a deposition temperature is selected according to a melting point of the high-hardness metal powder, to be lower than the melting point of the metal powder, so as to soften the metal powder but not to melt it.

8. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein a technic parameter of a carrier gas pressure of the cold spraying is 2 Mpa to 3 Mpa, a pre-heating temperature of the carrier gas is 300°

C. to 600°

C., a spraying distance is 15 mm to 40 mm, a powder feeding amount is 40 g/min to 80 g/min, the carrier gas is one of a compressed air or nitrogen gas.

9. The preparation method of the metal-based/diamond laser composite coating as claimed in claim 1, wherein the high-hardness metal powder is utilized to serve as a binding phase of the diamond composite coating;

a thickness of the composite coating is greater than 1 mm, and a volume content of diamond in the coating is greater than 45%.