Abstract
The role of both laser pulse length and duty cycle in controlling the grain size and crystallographic texture of diode laser-deposited Waspaloy powder is investigated. Thin-walled test structures of Waspaloy have been produced using a range of pulse parameters and analyzed by means of scanning electron microscopy and electron backscatter diffraction. Results have been correlated with a simple analytical model of the effect of the laser pulse on the substrate temperature and melt-pool geometry in order to help explain the trends observed. Findings show that pulse parameters have a marked effect on the resulting grain morphology and crystallographic orientation. Modelling has indicated that this arises because the microstructure is highly dependent on the melt-pool geometry, particularly the inclination angle of the melt-pool boundary. © 2008 Acta Materialia Inc.
Original language | English |
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Pages (from-to) | 1220-1229 |
Number of pages | 9 |
Journal | Acta Materialia |
Volume | 57 |
Issue number | 4 |
DOIs | |
Publication status | Published - Feb 2009 |
Keywords
- Electron backscatter diffraction
- Laser direct metal deposition (LDMD)
- Near-net shape manufacture
- Nickel alloys
- Texture