Laser engineered surfaces from glass forming alloy powder precursors: Microstructure and wear

Autor: V. Ocelik, David Thomas Allan Matthews, J.Th.M. De Hosson, D. Branagan
Přispěvatelé: Zernike Institute for Advanced Materials
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: Surface & Coatings Technology, 203(13), 1833-1843. Elsevier Science
ISSN: 0257-8972
Popis: Fe-based metallic glass forming powders have been deposited on mild steel substrates using high power laser cladding. Coatings microstructures have been analysed by scanning- and transmission-electron microscopy and at varying substrate dilutions, have been found to comprise a 100 to 500 nm interdendritic austenitic phase and a dendritic dual-phase of ferrite/martensite. The application of double layer coatings has shown microstructural refinement. This leads to a needle-like microstructure resulting in a nanoindentation tested hardness increase from similar to 11 GPa up to almost 15 GPa. The layers have been subjected to both dry sliding wear and 3-body microscale abrasive wear testing. The dry sliding results show the layers to exhibit excellent wear resistance - particularly at high speed (50 cm s(-1)) with wear rate values of similar to 1 x 10(-8) mm(3)/Nm being recorded for the double layer coatings. The single layer coatings reveal a micro-wear mechanism connected with the slip between the ferrite and martensite in the dendritic dual-phase. Microscale abrasive wear testing also reveals that the layers have a good wear resistance, with wear scars exhibiting characteristic material removal by micro-chipping. There is no preferential abrasion of any one phase, nor are track over-lap areas, cracks or pores found to result in varying wear scar dimensions. (C) 2009 Elsevier B.V. All rights reserved.
Databáze: OpenAIRE
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