Crystallographic texture and microstructure of pulsed diode laser-deposited Waspaloy

✍ Scribed by R.J. Moat; A.J. Pinkerton; L. Li; P.J. Withers; M. Preuss

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 809 KB
• Volume: 57
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.11.004

✦ Synopsis

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.