Three-dimensional printing of TiAl₃/Al₂O₃ composites

Abstract

Intermetallic/ceramic composites were fabricated by reactive infiltration of an Al melt into a porous TiO2 preform which was prepared by indirect three-dimensional printing. At 1450°C the highly negative Gibbs energy of reaction (Gr=–279.950kJ/mol) is the driving force for the redox reaction 13/2 Al+3/2 TiO23/2 TiAl3+Al2O3 to take place. Wetting of molten Al on the preform surface was improved by adding a carbon-bearing binder ((C6H10O5)n, dextrin) to the powder blend, which decomposed to amorphous carbon (carbon yield 25wt.% of initial dextrin weight) after being heat-treated up to 800°C in an inert atmosphere. During annealing to 1400°C, carbon partially reduced TiO2 at least on the surface of the grains to form Ti3O5 and Ti2O3, which exhibit a significantly lower wetting angle compared to TiO2. In a low-oxygen-containing inert atmosphere and at 1200°C, Al melt spontaneously penetrated into the printed preform via inter-agglomerate pores (mean size 8lm) and intra-agglomerate pores (mean size 1lm). A fine-grained TiAl3/Al2O3 composite microstructure was produced with a residual porosity of 9%.

Additive Manufacturing of Ceramic‐Based Materials

“…[85] Several research groups have intensively investigated the potential of manufacturing intermetallic/ceramic composites using a near-net-shape fabrication process involving infiltration of porous preforms fabricated by means of 3DP. Yin et al applied agglomerated powders [86] and freeze-dried granules [53,54] from TiC/TiO2/dextrin mixtures with varying blending ratios. Although the particle size of the feedstocks was comparable, the use of freeze-dried granules reduced the porosity of printed objects from 65% to 55%.…”

Three-dimensional printing of SiSiC lattice truss structures

“…Dense SiSiC was obtained by subsequent pyrolysis and pressureless liquid silicon melt infiltration [18]. Yin et al [19] built TiAl 3 /Al 2 O 3 composites by reactive infiltration of an Al melt into a porous TiO 2 preform which was prepared by indirect three-dimensional printing. Nan et al [20] reported the near-net-shape manufacturing of Ti 3 SiC 2 -based ceramics by three-dimensional printing combined with liquid silicon infiltration.…”

Near net-shape/net-dimension ZrC/W-based composites with complex geometries via rapid prototyping and Displacive Compensation of Porosity

“…While rapid prototyping methods have been used to prepare porous preforms for other reactive infiltration processes, no work has been conducted to date on the integration of rapid prototyping methods with a reactive infiltration process capable of generating dense, near net-dimension, ultrahigh-melting (>2500 • C) ceramic/metal composites. [38][39][40][41][42] The purpose of this paper is to evaluate the use of two rapid prototyping methods, 3D printing and computernumerical-controlled (CNC) machining, for fabricating shaped, porous WC preforms for subsequent conversion into dense, near net-shape/net-dimension ZrC/W-based composites.…”