International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The article reveals a new method that relates to the treatment of active surfaces of agricultural working bodies, in particular harrow discs, by applying nanostructured coatings using atmospheric plasma jet spraying (APS). The process consists of preparing the surface by corundum blasting at a pressure of 5.5 bar, followed by preheating to 150°C and depositing a nanostructured powder of the WC-Co 88/12 type.
The technical novelty lies in the synergetic optimization of the deposition parameters: current intensity of 550 A, hydrogen flow rate of 9 L/min, spraying distance of 100 mm and a high scanning speed of 500 mm/s, under forced post-deposition cooling.
The technical result obtained by applying this process consists of creating a protective layer with porosity below 1.2%, adhesion of over 65 MPa and a hardness of 1150-1250 HV0.3, ensuring an increase in the durability of the working element of up to 2.8 times under conditions of severe abrasive wear.

A comparative analysis of wear performance of coated harrow discs by plasma-jet thermal deposition was evaluated under agricultural conditions to assess the performance of atmospheric plasma spraying systems. This paper presents a long-term comparative field evaluation under identical operating conditions on a quartz-rich argic luvisol soil. Disc wear was quantified by periodic measurements of mass loss and diameter of the studied discs.
The uncoated disc showed the most severe degradation, with a total mass loss of approximately 700 g and a rapid acceleration of wear after the first 5-10 ha of harrowing. The results obtained under field conditions demonstrate that the microstructural integrity of the coating is more critical than the nominal hardness and highlight the superior effectiveness of APS ceramic coatings for extending disc life in abrasive agricultural soils.

The results of tribological tests of the active area of harrow disks with coatings obtained by the plasma spay thermal method are presented. This study is based on scanning electron microscopy of coated harrow disc samples undergoing standard tribological tests that focuses on the mechanical properties of coatings using tribological methodology. Tribological studies were conducted to determine the following main parameters of the harrow disc material such as: adhesion to the substrate, coefficient of friction, Young’s modulus, stiffness and hardness of coated samples and the base material. As the result, improving the mechanical and chemical properties of materials used to manufacture the working bodies of coated harrow discs allows for increased resistance to abrasive wear in modern agricultural machinery.

This study presents a comparative analysis of three types of coatings taken from the active area of the coted harrow disks using atmospheric plasma spray deposition method (APS). The resulting coatings increase the durability of the harrow discs and the inclusion in the componence of coatings of carbides and powdered ceramic compounds will enhance the mechanical characteristics. This study focused on scanning electron microscopy of the coated samples from the harrow discs and their tribological properties. SEM imaging and EDS analysis have been carried out to clarify the morphological characteristics and study of disc cross-section. Tribological tests were carried out to determine the following main parameters: adhesion to the substrate, coefficient of friction (COF), modulus of elasticity and hardness of the material.
The development and implementation of modern technologies for improving the mechanical and chemical properties of materials for
coated harrow discs will increase resistance to abrasive wear in modern agricultural conditions.