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Nickel-aluminum-based self-lubricating abrasion-resistant coating on surface of piston ring and preparation method

A wear-resistant coating and piston ring technology, which is applied in the coating, metal material coating process, fusion spraying, etc., can solve the problems of poor bearing capacity, poor wear-resistant and wear-reducing performance, and difficult to store lubricating oil, etc., to achieve Reduce friction and wear, good lubricating performance, improve the effect of public conditions

Inactive Publication Date: 2017-12-15
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The coating prepared by the two methods can improve the service life of the piston ring, but the coating is relatively dense, the porosity is low, it is difficult to store lubricating oil, and the friction coefficient under dry friction is relatively high, so the coating performance needs to be further improved
The invention patent with the publication number CN 1320767A uses physical vapor deposition (PVD) technology to form a TiCN or TiAlZr(CN) or TiCrNi(CN) titanium-based nano-ceramic coating on the piston ring. The dry friction coefficient of the coating is low. It can improve the service life of the piston ring, but the coating is thin and has poor bearing capacity, which is difficult to meet the requirements of high load and high speed of the engine
The invention patent with publication number CN101430004A uses PVD technology to prepare a composite coating with Cr bonding layer, Cr / CrN multi-layer coating and Cr / Cr2O3 multi-layer coating for wear-reducing layer. The coating is relatively thick. Good bearing capacity, but its friction coefficient is relatively high, and its wear resistance and wear reduction performance are poor

Method used

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Examples

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Effect test

preparation example Construction

[0025] The invention provides a coating preparation method, comprising: using nitrogen as powder to transport protective gas, argon and hydrogen as plasma spraying gas, using plasma flame to melt and spray formula materials on the surface of piston ring to obtain a piston ring surface coating . The present invention adopts thermal spraying process, and has certain requirements on spraying distance and spraying time. The spraying distance is controlled at 80-120mm, preferably at 90-100mm, and the spraying time is controlled at 10-20min. The spraying distance described in the present invention is the distance from the center of the plasma flame flow to the surface of the piston ring, and the temperature is the actual temperature of the piston ring during the coating preparation process.

[0026] When using the plasma spraying process to spray, the pressure of argon gas is 0.5-0.8 MPa; the pressure of nitrogen gas is 0.5-0.75 MPa; the pressure of hydrogen gas is 0.3-0.6 MPa. Th...

Embodiment 1

[0028] Ni powder with an average particle size of 30 μm, Mo powder with an average particle size of 22 μm, Al powder with an average particle size of 25 μm, Ag powder with an average particle size of 20 μm, and h-BN powder with an average particle size of 18 μm, according to 77wt%Ni, 4wt%Mo, 4wt%Al, 10wt%Ag, 5wt%h-BN were mechanically ball milled, mixed evenly, dried in a vacuum dryer to remove moisture;

[0029] The dry mixed powder is sprayed on the surface of the piston ring by a plasma spraying process to form a coating with a thickness of 200 μm. The specific spraying parameters are as follows: the air pressures of argon, nitrogen and hydrogen are 0.75MPa, 0.7MPa and 0.5MPa respectively; the powder flow rate is 15g / min; the spraying distance is 120mm; the spraying time is controlled as 15min; the rotation frequency of the piston ring is 25Hz ; The axial moving speed of the piston ring is 3mm / s.

[0030] The coating that obtains, adopts high-temperature ball-on-disk frict...

Embodiment 2

[0032] Ni powder with an average particle size of 35 μm, Mo powder with an average particle size of 20 μm, Al powder with an average particle size of 22 μm, Ag powder with an average particle size of 25 μm, and h-BN powder with an average particle size of 19 μm, according to 77wt %Ni, 4wt%Mo, 5wt%Al, 10wt%Ag, 4wt%h-BN were ball milled and mixed;

[0033] The mixed powder is sprayed on the surface of the piston ring by using a plasma spraying process to form a coating with a thickness of 200 μm. The specific spraying parameters are as follows: the pressures of argon, nitrogen and hydrogen are respectively 0.7MPa, 0.6MPa and 0.4MPa; the powder flow rate is 10g / min. The spraying distance is 100mm; the time is 10min, the rotation frequency of the piston ring is 20Hz, and the axial movement speed of the piston ring is 4mm / s.

[0034] The coating that obtains adopts high-temperature ball-on-disk friction and wear testing machine to measure the friction coefficient and wear resistan...

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Abstract

The present invention discloses a nickel-aluminum-based self-lubricating abrasion-resistant coating on the surface of a piston ring and a preparation method. The coating comprises 75wt%-78wt% of Ni, 4wt%-4.5wt% of Mo, 4wt%-4.5wt% of Al, 10wt%-12wt% of Ag and 3wt%-5wt% of h-BN; and the preparation method includes the preparation steps that Ni, Mo, Al, Ag and h-BN powder is subjected to mechanical ball-milling, and composite powder is prepared after drying; and the composite powder is sprayed on the surface of the outer circle of the piston ring by means of a plasma spraying method, and the coating is obtained. The coating obtained through the preparation method has a low friction coefficient and good lubricating performance, and the requirements of an engine for high efficiency, high load, long service life and the like are met; and the coating can form a new lubricating phase under high temperature, the friction abrasion can be effectively lowered, and the work condition of the piston ring is improved.

Description

technical field [0001] The invention relates to a nickel-aluminum-based self-lubricating wear-resistant coating on the surface of a piston ring and a preparation method thereof, belonging to the field of surface modification of engineering application materials. Background technique [0002] The piston ring is a metal ring embedded in the piston groove, which is the core component of the engine and directly affects the engine power and life. The surface modification technology of piston rings includes electroplating, nitriding, phosphating, etc. Among them, the electroplating Cr process consumes more energy and pollutes, and the Cr layer has higher hardness, but its porosity is low and the oil storage capacity is poor. Its brittleness and hardness produce hard particles, causing the engine to scuff; the nitriding process is stable and reliable, but the hardness of the nitriding layer is not high, and the thickness of the permeable layer cannot meet the requirements of the en...

Claims

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Application Information

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IPC IPC(8): C23C4/06C23C4/134C22C19/03
CPCC23C4/06C22C19/03
Inventor 李建亮李航熊党生何勇季钰涓
Owner NANJING UNIV OF SCI & TECH