Tribological Properties of ZrO2 Coating on the Ball Joint of an Axial Piston Pump in High Water-Based Emulsion Medium

Baofu Kou,Zhang Zhang,Zhenshun Li,Ruiqing Li,Zhigang Tao

doi:10.1155/2021/9978006

Baofu Kou, Zhang Zhang + Show 3 more

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https://doi.org/10.1155/2021/9978006

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Abstract

This paper studies the tribological properties of the ZrO2-coated spherical joint pair of the axial piston pump in a high water-based emulsion medium. Firstly, atmospheric plasma spraying was used to prepare the ZrO2 coating on the surface of the spherical joint pair. Secondly, the tribological characteristics of the steel-steel pair and ceramic-ceramic pair were analyzed by the friction and wear testing machine under the conditions of a high water-based emulsion concentration, load size, and load frequency. White light interference three-dimensional surface profiler and scanning electron microscope were used to analyze the original and worn surfaces of the samples, and then the friction and wear of the different material pairs were discussed. The results show that the friction reduction and wear resistance of the ceramic ball joint are superior to those of the steel ball joint. When the load is 100 N, the frequency is 1 Hz, and the emulsion concentration is 5%, and the friction coefficient and wear loss of the ceramic-ceramic ball joint pair are the lowest. The emulsion concentration and load have great influence on the friction coefficient and wear amount, while the frequency has little influence on them. With increasing concentration of the emulsion, the friction coefficient decreases and tends to be stable, but with increasing of load, the friction coefficient and wear increase. The friction coefficient and wear loss of the ceramic-ceramic ball joint in pure water are 0.25 times higher than those of the steel ball joint under the same working conditions. Therefore, when the concentration of the high water-based emulsion is 5%, 100 N load, 1 Hz frequency, the ceramic-ceramic ball joints display the best friction and wear resistance of the two. The research results provide a theoretical basis for the design, manufacture, and application of the ceramic coating hydraulic components in a high water-based emulsion medium.

Highlights

High water-based emulsion boasts good economy, viscositytemperature performance, rust resistance, and lubricity [1,2,3,4]. erefore, it is widely used in the hydraulic system valve groups of high mining equipment [5,6,7,8]
One of the most important systems is the application of the axial piston pump. e ball joint pair consists of a pair of key friction pairs in the axial piston pump, which is composed of a plunger ball head and a slipper ball concave
The plunger ball head bears all the pressure from the plunger, while moving relative to the slipper ball concave [13,14,15]. erefore, there is wear and mechanical efficiency loss in the ball joint pair, which in turn has a great impact on the thickness of the oil film and the tilting of the slipper pair

Summary

Introduction

High water-based emulsion boasts good economy, viscositytemperature performance, rust resistance, and lubricity [1,2,3,4]. erefore, it is widely used in the hydraulic system valve groups of high mining equipment [5,6,7,8]. Ball-block contact mode is used to carry out the friction and wear tests in different loads and frequencies, and with a high water-based emulsion concentration.

Results

Conclusion