Onset of selective laser flash sintering of AlN
[1];
[2];
[3]
- Department of Mechanical Engineering University of Texas at Austin Austin Texas USA
- Los Alamos National Laboratory Materials Science and Technology Division Los Alamos New Mexico USA
- Department of Mechanical Engineering University of Texas at Austin Austin Texas USA, Materials Science and Engineering Program University of Texas at Austin Austin Texas USA
Abstract Flash sintering uses a combination of heating and electric fields to rapidly densify ceramics. Previously, it has been shown that a scanning laser can be used to initiate flash sintering in localized regions on an yttria‐stabilized zirconia (YSZ) sample in a process known as selective laser flash sintering (SLFS). In this work, we show using a combination of measurements of electric current flowing through the sample and observations of necks formed between powder particles that aluminum nitride (AlN) can also undergo SLFS. Scan conditions required to initiate SLFS are characterized over a range of laser powers and laser scan speeds in a dry nitrogen environment. It is shown that initiation of SLFS in AlN is governed by both the local input energy density per scan and heat dissipation and a numerical model is developed to predict temperatures during SLFS. Assuming the minimum temperature along the conductive path determines the onset of SLFS, the minimum temperature and time required is 450–670 K in 2–0.25 s for the pressed AlN pellets used in this study for laser scan speeds of 33–300 m/s, laser powers of 10–30 W, and an applied electric field of 3000 V/cm.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1812404
- Journal Information:
- International Journal of Applied Ceramic Technology, Journal Name: International Journal of Applied Ceramic Technology Journal Issue: 6 Vol. 18; ISSN 1546-542X
- Publisher:
- Wiley-BlackwellCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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