Development of Nanostructured Composite Coatings on Metallic Surfaces

摘要: Abstract Theoretical research and some experimental work published in the scientific literature have shown that as grain structure of a material is reduced from micron- to nanoscale, size inherent defects also reduced. Furthermore, micromechanisms plastic deformation change presence boundaries triple junctions become very large compared conventional materials. This has effect changing mechanical properties nanostructured materials by increasing fracture toughness strength However, challenge arises how successfully develop surface order utilize unique superior offer. One technique with considerable potential thermal spraying. spraying process must be such flame temperature should controllable provide final coating minimum microstructural changes. Recent used high velocity oxy-fuel (HVOF) spray compare microstructured cermet coatings based on WC-Co system. HVOF suitable for powder feed onto steel surfaces changes decarburization/oxidation effects coating. The this chapter reviews use techniques method producing thick (300-500 μm) composite metallic surfaces. Previous control parameters route retaining nanostructure feedstock during presented. An alternative known cold gas dynamic (CGDS) compared. CGDS uses much lower process, can offer way reducing extent WC dissolution cobalt matrix produce enhanced tribological properties.