Search Results

You are looking at 1 - 2 of 2 items for

  • Author: W. Napadłek x
Clear All Modify Search
Open access

W. Napadłek

Abstract

The use of laser ablation phenomenon with the “thermal effect” to produce surface textures, mainly lubricant micro-containers in the form of spherical micro-bowls in the surface layer of 100CrMnSi6-4 alloy of bearing steel. This is interesting research topic. The application the local (zonal) laser hardening of the steel surface layer on the surface of the bearing raceway or casts gives technological opportunities to deploy those technologies in the production process. The article presents the selected results of the own laboratory studies of hardness, microstructure and surface stereometry bearing steel 100CrMnSi6-4 in different states after volume hardening and low tempering, as well as those obtained as a result of laser surface texturing and laser pulsed hardening. The study results can be used to modify the surface layer of 100CrMnSi6-4 bearing steel and in the nearest future use ablative laser texturing of the rolling bearings treadmill surface in the production of lubricanting micro-containers, for improving the wear resistance tribological pair of roller – raceway in the friction conditions.

Open access

B. Grabas, Sz. Tofil and W. Napadłek

Abstract

The paper deals with the laser beam welding of tips to central and side spark plug electrodes made of a nickel-chromium alloy. The tips attached to the central electrodes were made from a solid iridium wire 0.8 mm in diameter and 2 mm in length, while the tips connected to the side electrodes were made from a platinum wire 1.5 mm in diameter and 0.25 mm in thickness. In both cases, accurate positioning of the tips was required before they were resistance welded to the electrodes. Then, a fillet weld was produced with an Nd:YAG laser using single, partly overlapping conductive pulses. The laser welding was performed at different laser power levels and pulse durations. Metallographic sections of the joints were prepared to observe changes in the microstructure and determine their correlation with the changes in the process parameters. The results were used to select appropriate welding parameters for the materials joined. The microscopic analysis indicated welding imperfections such as micro cracks at the interface between the elements joined. The tips welded to the spark plug electrodes can help extend the service life of spark plugs in highly corrosive environments.