Plasma activated sintering of additive-free AlN powders to near-theoretical density in 5 minutes

Abstract

AlN powders (particle size = 0.44 ± 0.08 μm) containing no deliberate sintering additives were consolidated to near theoretical density in 5 min at 2003 K (1730 °C) using a Plasma Activated Sintering (PAS) process. PAS is a novel consolidation method that combines a very short time at high temperature with pressure application in a plasma environment. The in situ cleaning ability of powder particle during plasma activated densification leads to enhanced particle sinterability. The densities of undoped AlN specimens that were PAS consolidated at 2003 K for 5 min under 50 MPa pressure ranged from 97.5 to 99.3% of theoretical. The initial submicron particle size of AlN powders was retained in the final microstructure that consisted of polycrystalline grains with an average size of ≍0.77 ± 0.1 μm.

Effects of heating rate on densification and grain growth during field-assisted sintering of α-Al2O3 and MoSi2 powders

“…observed by high resolution electron microscopy (HREM) in ceramics and metals. [8,9,10] Usually, FAST-sintered materials are characterized by high densities and fine grain sizes. For instance, sintering to full density of AlN at 2000 K for II.…”

“…EXPERIMENTAL 5 minutes maintained the initial submicron grain size (final 0.77 from initial 0.44 m). [8] Fine grain sizes have been Both ␣-Al 2 O 3 powder (Sumitomo Chemical Co., Japan) with a particle size of 0.1 m and MoSi 2 powder (Aldrich typically retained in FAST-sintered nanosize powders. In…”

Inkjet Printing and Alternative Sintering of Narrow Conductive Tracks on Flexible Substrates for Plastic Electronic Applications

“…This thermal sintering method usually requires temperatures above 200 °C (Chou et al, 2005). Other techniques that have been used to for conductive features include LASER sintering (Ko et al, 2007), exposure to UV radiation (Radivojevic et al, 2006), high temperature plasma sintering (Groza et al, 1992) and pulse electric current sintering (Xie et al, 2003). However, most of these techniques are not suitable for polymer substrate materials due to the large overall thermal energy impact.…”

Proton-induced X-ray emission (PIXE) characterization of special glasses and multi-coated lenses

“…PIXE is especially useful for the rapid, nondestructive analysis of high purity materials in air, which is currently being applied to advanced ceramics, such as aluminum nitride, alumina, and zinc oxide formed by plasma-activated sintering of additive free powders [9,10].…”