Abstract
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 ~ 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 ~ 1 × 10- 8 mm3/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.
Original language | English |
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Pages (from-to) | 1833-1843 |
Number of pages | 11 |
Journal | Surface and coatings technology |
Volume | 203 |
Issue number | 13 |
Early online date | 19 Jan 2009 |
DOIs | |
Publication status | Published - 25 Mar 2009 |
Externally published | Yes |
Keywords
- Laser
- Metallic glass
- Microscopy
- Nanosteel
- Wear resistance