Nickel-coated hexagonal boron nitride nanosheet composite powder, preparation and high performance composite ceramic cutting tool material

Patent metadata

Field	Value
Publication number	US-2021214280-A1
Application number	US-201916765131-A
Country	US
Kind code	A1
Filing date	Nov 8, 2019
Priority date	Jan 29, 2019
Publication date	Jul 15, 2021
Grant date	—

Abstract

The invention relates to nickel-coated hexagonal boron nitride nanosheet composite powder, its preparation and high-performance composite ceramic cutting tool material. The composite powder has a core-shell structure with BNNS as the core and Ni as the shell. The self-lubricating ceramic cutting tool material is prepared by wet ball milling mixing and vacuum hot-pressing sintering with a phase alumina as the matrix, tungsten-titanium carbide as the reinforcing phase, nickel-coated hexagonal boron nitride nanosheet composite powder as the solid lubricant and magnesium oxide and yttrium oxide as the sintering aids. The invention also provides preparation methods of the nickel-coated hexagonal boron nitride nanosheet composite powder and the self-lubricating ceramic cutting tool material.

First claim

What is claimed is:

1 . A nickel-coated hexagonal boron nitride nanosheet composite powder (BNNS@Ni), wherein the composite powder has a core-shell structure with BNNS as the core and Ni as the shell.

2 . The nickel-coated hexagonal boron nitride nanosheet composite powder (BNNS@Ni) as claimed in claim 1 , wherein the Ni particles in the nickel-coated hexagonal boron nitride nanosheet composite powder are uniform in size, and uniformly coated on the surface of the BNNS.

3 . The nickel-coated hexagonal boron nitride nanosheet composite powder (BNNS@Ni) as claimed in claim 1 , wherein the average sheet diameter of BNNS in the nickel-coated hexagonal boron nitride nanosheet composite powder is 100-800 nm, and the average sheet thickness is 1-7 nm.

4 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder (BNNS@Ni) as claimed in claim 1 , comprises the following steps:
(1) the BNNS powder is proportionally weighed, added into an appropriate amount of isopropanol, ultrasonically dispersed for 20-30 min, and then centrifugally separate to obtain the dispersed BNNS powder; (2) the dispersed BNNS powder obtained in step (1) is added into the sensitizing solution, ultrasonically oscillated and stirred for 10-15 min, centrifugally separated after the tin particles in the sensitizing solution are filtered out, and washed once with distilled water to obtain sensitized BNNS powder; the components of the sensitizing solution are: 10-15 g/L of stannous chloride dihydrate, the balance is isopropanol, and 3-5 g/L of tin particles are added; (3) the sensitized BNNS powder obtained in step (2) is added into the activating solution, ultrasonically oscillated and stirred for 10-20 min, centrifugally separated and washed to neutrality with distilled water to obtain activated BNNS powder. Then it is added into an appropriate amount of PVP solution, ultrasonically oscillated and stirred for 5-10 min to prepare activated BNNS suspension, which is sealed for later use; the components of the activating solution are: 0.2-0.5 g/L of palladium chloride (PdCl 2 ), 5-10 mL/L of concentrated hydrochloric acid, 5-10 mg/L of polyvinylpyrrolidone (PVP), and the balance is distilled water; (4) electroless plating solution is prepared, and the components of the electroless plating solution are: 15-25 g/L of nickel sulfate hexahydrate, 50-60 g/L of ethylenediamine tetraacetic acid disodium dihydrate, 40-50 g/L of ammonium sulfate, 15-25 mL/L of the first dose of hydrazine hydrate, 5-10 mg/L of polyvinylpyrrolidone, 0.2-0.5 mg/L of potassium iodide, an appropriate amount of pH adjuster makes the pH value of the electroless plating solution at 10-11, and the balance is distilled water; In addition, 15-25 mL/L of the second dose of equal amount of hydrazine hydrate is prepared for later use; the activated BNNS suspension obtained in step (3) is added into the prepared electroless plating solution. First, the plating is carried out for 5-10 min in a constant temperature water bath at 85-90° C. and under ultrasonic oscillation condition, then the second dose of hydrazine hydrate is added dropwise under stirring condition. Afterwards the plating is carried out in a constant temperature water bath at 50-60° C. and under ultrasonic oscillation condition, and the pH adjuster is dripped at any time to keep the pH value of the electroless plating solution at 10-11; (5) after the plating in step (4) is completed, the solid particles are centrifugally separated and washed to neutrality with distilled water, then washed with absolute ethanol for 2-3 times, and dried in a vacuum drying oven at 30-40° C. for 10-15 h to obtain nickel-coated hexagonal boron nitride nanosheet composite powder.

5 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder as claimed in claim 4 , wherein the average particle size of the tin particles in step (2) is 1-2 mm; when the BNNS powder is sensitized in step (2), the addition amount of BNNS powder is 1-2 g/L per liter of the sensitizing solution.

6 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder as claimed in claim 4 , wherein when the BNNS powder is activated in step (3), the addition amount of BNNS powder is 0.5-1 g/L per liter of the activating solution.

7 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder as claimed in claim 4 , wherein the concentration of the PVP solution in step (3) is 5-10 mg/L; It is prepared with distilled water.

8 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder as claimed in claim 4 , wherein in step (4), the pH adjuster of the electroless plating solution is NaOH solution with a mass fraction of 7-8%.

9 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder as claimed in claim 4 , wherein in step (4), the components of the electroless plating solution are: 20 g/L of nickel sulfate hexahydrate, 55 g/L of ethylenediamine tetraacetic acid disodium dihydrate, 45 g/L of ammonium sulfate, 20 mL/L of the first dose of hydrazine hydrate, 7 mg/L of PVP, 0.3 mg/L of potassium iodide, an appropriate amount of pH adjuster makes the pH value of the electroless plating solution at 10-11, and the balance is distilled water; In addition, 20 mL/L of the second dose of equal amount of hydrazine hydrate is prepared for later use;

10 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder as claimed in claim 4 , wherein the preparation steps of the electroless plating solution in step (4) are as follows:
1) NiSO 4 .6H 2 O and Na 2 C 10 H 14 N 2 O 8 .2H 2 O are proportionally weighed, respectively added into an appropriate amount of distilled water, ultrasonically oscillated and stirred for dissolution to obtain NiSO 4 .6H 2 O solution and Na 2 C 10 H 14 N 2 O 8 .2H 2 O solution, respectively; 2) under ultrasonically oscillating and stirring conditions, NiSO 4 .6H 2 O solution is slowly added into Na 2 C 10 H 14 N 2 O 8 .2H 2 O solution to obtain solution a; 3) (NH 4 ) 2504 is weighed in proportion, added into solution a, ultrasonically oscillated and stirred for dissolution to obtain solution b; 4) NaOH is weighed in proportion, added into distilled water measured in proportion, ultrasonically oscillated and stirred for dissolution to prepare NaOH solution with mass fraction of 7-8%; 5) under the conditions of ultrasonically oscillating and stirring, the NaOH solution obtained in step 4) is added dropwise to solution b until the pH value reaches 10-11 to obtain solution c; 6) the first dose of hydrazine hydrate is measured in proportion, dripped into the solution c under the conditions of ultrasonically oscillating and stirring, and then distilled water is added to the total volume of the electroless plating solution to obtain solution d; 7) PVP and KI are weighed in proportion, added into the solution d successively, ultrasonically oscillated and stirred for dissolution to obtain the electroless plating solution.

11 . The preparation method of the nickel-coated hexagonal boron nitride nanosheet composite powder as claimed in claim 4 , wherein during the electroless plating in step (4), the addition amount of BNNS powder is 0.2-0.5 g/L per liter of the electroless plating solution.

12 . The application of the nickel-coated hexagonal boron nitride nanosheet composite powder (BNNS@Ni) as claimed in claim 1 is used as a solid lubricant in self-lubricating ceramic cutting tool materials.

13 . A self-lubricating ceramic cutting tool material add

Assignees

• Univ Qilu Technology

Inventors

• Xu Chonghai
• Wu Guangyong
• Xiao Guangchun
• Yi Mingdong
• Chen Zhaoqiang
• Zhang Jingjie

Classifications

• B22F1/18

  Non-metallic particles coated with metal · CPC title

• C23C18/34

  using reducing agents · CPC title

• C23C18/1689

  After-treatment · CPC title

• C23C18/1675

  Process conditions · CPC title

• C23C18/1889

  with use of metal first · CPC title