Method for preparing ammonium thiomolybdate-porous amorphous carbon composite superlubricity film

Abstract

A method for preparing an ammonium thiomolybdate-porous amorphous carbon composite superlubricity film is disclosed. First, a porous amorphous carbon film is prepared by an anode layer ion source assisted plasma chemical vapor deposition method and a reactive magnetron sputtering method on a substrate. The porous amorphous carbon film is then impregnated in an ammonium thiomolybdate solution, so that the ammonium thiomolybdate is adsorbed on the porous amorphous carbon film, and the impregnated porous amorphous carbon film is air dried. During the friction process, the composited porous amorphous carbon superlubricity film prepared in the present disclosure promotes the in-situ decomposition of ammonium thiomolybdate to generate molybdenum disulfide by utilizing the friction heat at the initial stage of running-in, further to generate a graphene-like structure under the function of a catalyst, thus realizing a macroscopic super lubricity through a heterogeneous incommensurate contact between graphene and molybdenum disulfide.

Claims

1. A method for preparing an ammonium thiomolybdate-porous amorphous carbon composite superlubricity film, comprising: preparing a transition layer by: cleaning a substrate under ultrasound, placing the cleaned substrate in a vacuum chamber, vacuuming the vacuum chamber to 1×10.sup.−3 Pa, performing a deposition for 20 minutes by magnetron sputtering utilizing a Ti.sub.0.7Ni.sub.0.3 target under conditions of a magnetron sputtering current of 5 A, and an argon pressure of 1 Pa, under the conditions, introducing an argon mixture containing nitrogen, and performing another deposition for 40 minutes, to obtain a transition layer on the substrate; preparing a porous amorphous carbon film by: performing reactive magnetron sputtering utilizing an aluminum-carbon composite target containing aluminum, under conditions of reaction gases being argon, carbon tetrafluoride, hydrogen and oxygen with a flow ratio of 2:1:1:0.2, a pressure of 1-3 Pa, a magnetron sputtering current of 4 A, and a deposition time of 40-60 minutes, to obtain a porous amorphous carbon film; preparing an ammonium thiomolybdate solution by: dissolving ammonium thiomolybdate solid powder in deionized water, and stirring the resulting mixture with a magnetic stirrer under ultrasound, to obtain an ammonium thiomolybdate solution with a concentration of 1 to 3% mass/volume; preparing the ammonium thiomolybdate-porous amorphous carbon composite superlubricity film by: impregnating the porous amorphous carbon film in the ammonium thiomolybdate solution for 4 to 5 hours, and taking the impregnated porous amorphous carbon film out and air drying, to obtain the ammonium thiomolybdate-porous amorphous carbon composite superlubricity film.

2. The method for preparing the ammonium thiomolybdate-porous amorphous carbon composite superlubricity film as claimed in claim 1, wherein, in the step of preparation of a transition layer, the substrate is selected from the group consisting of: stainless steel, gear steel, bearing steel, and combinations thereof.

3. The method for preparing the ammonium thiomolybdate-porous amorphous carbon composite superlubricity film as claimed in claim 1, wherein, in the step of preparation of an ammonium thiomolybdate solution, the ammonium thiomolybdate is selected from the group consisting of: ammonium trithiomolybdate, ammonium tetrathiomolybdate, ammonium pentathiomolybdate, and combinations thereof.

4. The method for preparing the ammonium thiomolybdate-porous amorphous carbon composite superlubricity film as claimed in claim 1, wherein, in the step of preparation of an ammonium thiomolybdate solution, the ultrasound has a power of 500 W, and a frequency of 200 Hz, and the stirring is performed at a rotation speed of 10 revolutions per minute.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A shows a scanning electron microscope image illustrating the surface structure of the ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film prepared in some embodiments of the present disclosure.

(2) FIG. 1B shows a scanning electron microscope image illustrating a cross section view of the ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film prepared in some embodiments of the present disclosure.

(3) FIG. 2 shows a friction curve of the ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film prepared in some embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) The preparation and performance of the ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film of the present disclosure will be further illustrated with reference to specific examples below.

Example 1

(5) (1) Preparation of a porous amorphous carbon film: the porous amorphous carbon film was prepared on a substrate by an anode layer ion source assisted plasma chemical vapor deposition method and a reactive magnetron sputtering method. The specific procedures were as follows:

(6) i. cleaning of the substrate: the stainless steel substrate was cleaned under an ultrasonic, and the cleaned stainless steel substrate was put into a vacuum chamber, and then the vacuum chamber was vacuumed to 1×10.sup.−3 Pa to start a deposition;

(7) ii. deposition of a transition layer: deposition was performed by a magnetron sputtering method by utilizing Ti.sub.0.7Ni.sub.0.3 target for 20 minutes, under conditions of a current of 5 A, a deposition bias voltage of 200 V, argon atmosphere, and a pressure of 1 Pa; under the above conditions unchanged, an argon mixture containing nitrogen was introduced, and another deposition was performed for 40 minutes;

(8) iii. preparation of a porous carbon film: a magnetron sputtering was performed by utilizing aluminum-carbon composite target containing aluminum, under conditions of reaction gases being argon, carbon tetrafluoride, hydrogen and oxygen with a flow ratio of 2:1:1:0.2, a pressure of 1 Pa, a magnetron sputtering current of 4 A, and a time of 60 minutes, obtaining a porous carbon film, which comprises a microporous with a diameter of 20-40 nm.

(9) (2) 0.1 g of ammonium tetrathiomolybdate solid powder was dissolved in 10 mL of deionized water, and they were stirred with a magnetic stirrer under an ultrasonic, obtaining an ammonium tetrathiomolybdate solution with a concentration of 1%, wherein the ultrasonic has a power of 500 W, and a frequency of 200 Hz, and the stirring was performed at a rotation speed of 10 revolutions per minute.

(10) (3) The prepared porous amorphous carbon film was impregnated in the ammonium tetrathiomolybdate solution with a concentration of 1% for 5 hours, and the impregnated porous amorphous carbon film was air dried, obtaining an ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film.

(11) (4) The ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film was subjected to a friction test under conditions of a load of 5 N, a frequency of 5 Hz, a diameter of counterpart balls of 6 mm, a testing sustaining time of 30 min, and a reciprocating distance of 5 mm, and the results showed that the average friction coefficient was 0.0057, as shown in FIG. 2.

Example 2

(12) (1) Preparation of a porous amorphous carbon film: the porous amorphous carbon film was prepared on a substrate by an anode layer ion source assisted plasma chemical vapor deposition method and a reactive magnetron sputtering method. The specific procedures were as follows:

(13) i. cleaning of the substrate: a gear steel substrate was cleaned under an ultrasonic, and the cleaned stainless steel substrate was put into a vacuum chamber, and then the vacuum chamber was vacuumed to 1×10.sup.−3 Pa to start a deposition;

(14) ii. deposition of a transition layer: deposition was performed by a magnetron sputtering method by utilizing Ti.sub.0.7Ni.sub.0.3 target for 20 minutes, under conditions of a current of 5 A, a deposition bias voltage of 200 V, argon atmosphere, and a pressure of 1 Pa; under the above conditions unchanged, an argon mixture containing nitrogen was introduced, and another deposition was performed for 40 minutes;

(15) iii. preparation of a porous carbon film: a magnetron sputtering was performed by utilizing aluminum-carbon composite target containing aluminum, under conditions of reaction gases being argon, carbon tetrafluoride, hydrogen and oxygen with a flow ratio of 2:1:1:0.2, a pressure of 1 Pa, a magnetron sputtering current of 4 A, and a deposition time of 60 minutes, obtaining a porous carbon film, which comprises a microporous with a diameter of 20-40 nm.

(16) (2) 0.2 g of ammonium tetrathiomolybdate solid powder was dissolved in 10 mL of deionized water, and they were stirred with a magnetic stirrer under an ultrasonic, obtaining an ammonium tetrathiomolybdate solution with a concentration of 1%, wherein the ultrasonic has a power of 500 W, and a frequency of 200 Hz, and the stirring was performed at a rotation speed of 10 revolutions per minute.

(17) (3) The prepared porous amorphous carbon film was impregnated in the ammonium tetrathiomolybdate solution with a concentration of 1% for 5 hours, and the impregnated porous amorphous carbon film was air dried, obtaining an ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film.

(18) (4) The ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film was subjected to a friction test under conditions of a load of 5 N, a frequency of 5 Hz, a diameter of counterpart balls of 6 mm, a testing sustaining time of 30 min, and a reciprocating distance of 5 mm, and the results showed that the average friction coefficient was 0.0053.

Example 3

(19) (1) Preparation of a porous amorphous carbon film: the porous amorphous carbon film was prepared on a substrate by an anode layer ion source assisted plasma chemical vapor deposition method and a reactive magnetron sputtering method. The specific procedures were as follows:

(20) i. cleaning of the substrate: a bearing steel substrate was cleaned under an ultrasonic, and the cleaned stainless steel substrate was put into a vacuum chamber, and then the vacuum chamber was vacuumed to 1×10.sup.−3 Pa to start a deposition;

(21) ii. deposition of a transition layer: deposition was performed by a magnetron sputtering by utilizing Ti.sub.0.7Ni.sub.0.3 target for 20 minutes, under conditions of a current of 5 A, a deposition bias voltage of 200 V, argon atmosphere, and a pressure of 1 Pa; under the above conditions unchanged, an argon mixture containing nitrogen was introduced, and another deposition was performed for 40 minutes;

(22) iii. preparation of a porous carbon film: a magnetron sputtering was performed by utilizing aluminum-carbon composite target containing aluminum, under conditions of reaction gases being argon, carbon tetrafluoride, hydrogen and oxygen with a flow ratio of 2:1:1:0.2, a pressure of 1 Pa, a magnetron sputtering current of 4 A, and a deposition time of 60 minutes, obtaining a porous carbon film, which comprises a microporous with a diameter of 20-40 nm.

(23) (2) 0.3 g of ammonium tetrathiomolybdate solid powder was dissolved in 10 mL of deionized water, and they were stirred with a magnetic stirrer under an ultrasonic, obtaining an ammonium tetrathiomolybdate solution with a concentration of 1%, wherein the ultrasonic has a power of 500 W, and a frequency of 200 Hz, and the stirring was performed at a rotation speed of 10 revolutions per minute.

(24) (3) The prepared porous amorphous carbon film was impregnated in the ammonium tetrathiomolybdate solution with a concentration of 1% for 5 hours, and the impregnated porous amorphous carbon film was air dried, obtaining an ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film.

(25) (4) The ammonium tetrathiomolybdate-porous amorphous carbon composite superlubricity film was subjected to a friction test under conditions of a load of 5 N, a frequency of 5 Hz, counterpart balls having a diameter of 6 mm, a testing sustaining time of 30 min, and a reciprocating distance of 5 mm, and the results showed that the average friction coefficient was 0.0052.