Publication presents an analysis of possibility of applying ablation laser texturing of 100CrMnSi6-4 bearing steel in the tribological aspect. Selection of different variants of laser micromachining, including pulsed radiation (λ=1.064 μm), and different variants of geometric surface texture, characteristic surface stereometry was obtained with regular arranged lubrication microchannels on the surface roller bearing steel. Maximal hardness in the melted and laser hardened zone, inside the micro-container and in its nearby zone, increased up to 800÷1000 HV0.05 (about 60÷75% increase) in comparison to the core hardness (610÷660 HV0.05). Local hardness increase even up to 1100 HV0.05 was noticed. No micro-cracks in the surface layer neither in the lubricant micro-containers were found. Moreover, no material degradation in the cross-sections in the micro-containers was noticed.
The paper presents the results of laboratory tests of test specimens produced by multi-layer laser padding alloy Stellit Co-6 powder on a substrate with heat-treated X22CrMoV12-1 alloy steel. Multilayer laser padding was performed on a TRUMPF TruLaser Cell 3008. The formed weld overlays surface was studied using an optical microscope. Selected usable properties, such as surface topography, microstructure, hardness and erosion resistance were studied. During the analysis, areas of cross-sections test specimens after multilayer laser padded, in the connection zone of the substrate material with weld overlay, no cracks and no discontinuities in weld overlay were found in the substrate. As a result of conducted experiments, regular, repetitive weld overlays with characteristic directional crystallization were obtained. A microstructure with different growth directions with respect to the surface of the substrate shaped coniferous dendrites was obtained. The hardness of the weld overlays was in the range from 420 to 620 HV0.1, and in the heat affected zone, in the range of 320 to 420 HV0.1. Significant increases in erosion resistance of the surface layer of Stellite type Co-6 weld overlay produced by laser in comparison with the parent material after hardening were found.
In this paper, selected examples of the laser texturing of the surface layer patterning of the elements of the combustion engines were presented. A laser oil micro-container fabrication method was presented. Finishing cylinder liner, spigot of the camshaft, spigot of the crankshaft, rod and piston pin of the combustions engine were patterned. Laser patterning was done with the Nd: YAG laser with wavelength of λ=1064 nm. The manufactured micro-containers provide better lubrication of the friction associations. The conducted experiments allowed obtaining very regular surface texture what was found to be advantageous to the tribological processes and decrease of the wear of the frictional association in the combustions engines. Micro-bowls and micro-grooves were formed on the selected elements of the crank-piston elements and timing gear elements, including: the main spigots and rod spigots of the crankshaft, side surfaces of the base and the connecting rod head, piston pin and peg of the camshaft of the ZI type 126A1 engine. Textured elements of the piston-rod system and the camshaft were then successfully applied in a real object in so-called "cold ignitions" in low temperature chamber. With the use of laser ablation texturing, at optimized experimental parameters, it is possible to form on the piston-rod and timing gear elements oil micro-containers with varied shapes and surface coverage. It allows improving the association conditions in these systems, especially due to the formation of oil microfilm, which efficiently separates mentioned elements even while under high thermal, heat and mechanical load.
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