Dispersed Ceo2 Nanorods with Low-Speed Mixing for Grain Orientation Refine and Mechanical Properties Promotion of Pta Steel Coatings

Abstract

Alloy coatings had gained considerable importance in recent times for their high wear resistance and exceptional toughness. As a result, there has been a continuous improvement in methods to fabricate alloy coatings with superior properties for advanced applications in industries such as automotive, aerospace, medical treatment, and energy source. Plasma transferred arc (PTA) technology that is seen to promote preferential grain orientation in different directions, leading to nonuniform grain growth within the alloy coating material. Nano oxides can serve as heterogeneous nucleation sites to reduce the preferred orientation of grains. The present study employs a low-speed mixing method to coat highly dispersed CeO2 nanorods (CNRs) onto the surface of 14Cr2NiSiVMn alloy powder particles. The influence of dispersed CNRs on the grain growth orientation in different directions, and the refinement and heterogeneous nucleation effect of CNR additives were analyzed. An addition of 0.5 wt.% CNRs led to refined dendritic grains along the directions perpendicular and parallel to the coating cladding direction, resulting in more uniform equiaxed grains. The Ce combined with Si and V elements to form a submicron particle, which promoted grain nucleation and reduced defects in the coating. Consequently, the mechanical performance of the sample significantly improved. There was an improvement in microhardness (21.4%), tensile strength (97.6%) along the deposition direction, and elongation (59.0%). In the perpendicular deposition direction, the tensile strength and elongation increased by 88.1% and 33.9%, respectively. Additionally, the weight loss due to wear reduced by 44.2%, while the relative wear resistance improved by 79.3%.

Keywords: Plasma transferred arc, Alloy steel coating, CeO2 nanorods, Preferred orientation, mechanical properties