Title
Microstructure, microhardness and fracture toughness of borochromized layers modified with laser beam
Authors
[ 1 ] Instytut Inżynierii Materiałowej, Wydział Inżynierii Materiałowej i Fizyki Technicznej, Politechnika Poznańska | [ 2 ] Instytut Technologii Materiałów, Wydział Inżynierii Mechanicznej, Politechnika Poznańska | [ P ] employee
Scientific discipline (Law 2.0)
Year of publication
2024
Chapter type
chapter in monograph / paper
Publication language
english
Keywords
EN
- Boronized layer
- borochromized layer
- laser modification
- microhardness
- fracture toughness
Abstract
EN The paper presents the influence of laser beam on properties of borochromized surface layers produced on C45 steel. Microstructure, phase composition, microhardness as well as fracture toughness of newly formed layers were studied. Analyzd layers were produced using by three methods. First was galvanic-diffusion method, second was galvanic-diffusion method with additional laser modification, and third was galvanic method with additional laser alloying using boron paste. During all processes the thickness of galvanic coatings was 5 µm. For samples where diffusion boronizing was carried, temperature of 950 °C and process time of 4 h was applied. As a result of this process dual-zone microstructure was obtained. On surface continuous zone was observed while on subsurface needle-like iron borides was identified. For the samples where no diffusion boronizing was used, amorphous boron paste was applied to the galvanic chromium coating. In these studies the CO2 laser beam was used for modification processes. Application of laser beam contributed to obtain three microstructural zones: remelted zone, heat affected zone and substrate. In produced layers phases of iron borides and chromium borides were identified. These phases were in accordance with equilibrium diagrams: Fe-B, and Cr-B. An advantageous effect of laser modification on microhardness of borochromized layers was found. Produced layers were compared with diffusion boronized layers. Microhardness profiles showed gradual transition from the remelted zone, through heat affected zone to the substrate. It was found that brittleness of boronized layer decreases after modification with chromium and the laser beam.
Date of online publication
02.12.2024
Pages (from - to)
299 - 304
License type
CC BY (attribution alone)
Open Access Mode
publisher's website
Open Access Text Version
final published version
Date of Open Access to the publication
at the time of publication
Ministry points / chapter
5
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