Improvement of Wear Resistance in Toothed Harrows Coated with HVOF and PVD Methods

Surfaces of the toothed harrow were improved by using different coating materials and methods. Four different coating methods and special alloy powders were used as coating materials. TiCN was applied with PVD, and the WC-Ni-Co-Cr-Si-Fe-B powder mixture was applied with HVOF. The coating thicknesses was ۲ µm and ۵ µm in PVD, ۵۰۰ µm in the HVOF, and ۵۰۰+۲ µm in the application where HVOF + PVD were used together. The wear trials were carried out in the laboratory, at a ۵۰ km distance, in a double-speed trial pattern that converted circular motion to linear motion. The trial model was used to simulate the wear that occurs under real operating conditions in the soil. As a result of the wear trials carried out under the same operating conditions, a total material loss of ۳.۹۹ g occurred in the control (uncoated) harrow, the wear resistance increased, and less material loss was observed in the coated harrows. The sample coated with the PVD method had the lowest value with a material loss of ۰.۱۴ g. Material loss for other coated samples PVD-۵µ, HVOF-۵۰۰µ, and PVD-۲µ+HVOF-۵۰۰µ was ۰.۱۹, ۰.۲۸, and ۰.۱۸ g, respectively. When the amount of wear in the uncoated sample was ۱۰۰%, the proportional loss in PVD-۲µ, PVD-۵µ, HVOF-۵۰۰µ, and PVD-۲µ+HVOF-۵۰۰µ coated samples was calculated as ۳.۴۱, ۴.۸۵, ۷.۱۶, and ۴.۵۷%, respectively.

Keywords:

Agricultural Machinery , Abrasion , Material loss , Coating.