Characterization of Thermal Spray Coatings for Cylinder Running Surfaces of Diesel Engines

Abstract

Future demands of diesel engines are about low-friction and wear-resistant materials in order to increase the efficiency and achieve environmentally sound solutions. Thus, thermally sprayed Fe-base coatings are investigated for application as cylinder running surfaces in cast aluminum crankcases. They should allow the desired combination of structural, productional, and topographical properties required in Diesel engines. To understand the influence of the characteristic microstructures on the integrity of the composites the coatings have to be examined in laboratory tests in terms of different loading situations. Cavitation tests were carried out where the tribological stability of these coatings and their ability to resist high-frequency cyclic impact stresses are revealed. Composite samples (base material and coating) were investigated in terms of crack initiation in a scanning electron microscope with an in situ 3-pointbending test. The endurance under cyclic mechanical stresses was tested with a 4-point-bending stress controlled test.

Effects of post annealing on the microstructure, mechanical properties and cavitation erosion behavior of arc-sprayed FeNiCrBSiNbW coatings

“…A series of Fe-based amorphous coatings were prepared by arc spraying process recently. The investigation showed they had higher hardness, better corrosion, wear and cavitation erosion resistance compared to the conventional crystalline materials [9][10][11][12][14][15][16][17][18].…”

CFD Enhanced Thermal Spray Process for Coating of Cylinder Bores of Car Engines

“…By replacing the heavy gray cast iron liners with the typical honing structure with a thin, smooth cylinder coating, friction losses can be significantly decreased. Due to the small layer thickness of the cylinder coating, the crankcase can be downsized, thus further reducing the weight ( Ref 7,[9][10][11][12]. There are various technologies to coat the internal diameter of cylinder bores, e.g., plasma-transferred wire arc (PTWA) (Ref [13][14][15], rotation single wire (RSW) (Ref 16), cold spray (CS) (Ref 17), high-velocity oxygen fuel (HVOF) ( Ref 12,18) or atmospheric plasma spraying (APS) ( Ref 18).…”

Effect of Initial Surface Roughness on Cavitation Erosion Resistance of Arc-Sprayed Fe-Based Amorphous/Nanocrystalline Coatings

“…In recent years, considerable efforts have been devoted to investigate the cavitation erosion behavior of Fe-based amorphous/nanocrystalline coatings [13][14][15][16][17][18][19][20][21]. According to [13,18], the high-velocity oxygen-fuel (HVOF) sprayed Fe-based amorphous/nanocrystalline coatings with dense structure and high microhardness were preferable to improve the resistance of cavitation erosion in deionized water.…”