Characterization of a high temperature ceramics produced via two-step additive manufacturing

Abstract

Selective laser sintering (SLS) is a prospective technology to manufacture ceramic of complex geometry. However it is limited by the poor sinterability of ceramics and steady cracks formation. The paper highlights a new strategy to fabricate ceramics produced via two-step procedure: metal-ceramic green body manufacturing by SLS with further conversion into the Al2O3-based ceramics by high-temperature oxidation. Via shrinkage test it was shown that the developed production process could be treated as non-shrinkable since the deviations in the samples linear dimensions are less than 0.3–0.4%. According to XRD results produced material is suitable for a long-term exploitation (>1000 h) at temperatures below 1250 °C and for a short-time (1–2 h) usage at 1300 °C. The thermal expansion of the material is close to that typical for alumina-based ceramics, it is constant up to 1000 °C with a following slight decrease up to 1400 °C due to microamounts of mullite formation.

Keywords

• Selective laser sintering
• Powder bed fusion
• Selective laser melting