Injection Molding and Near-Complete Densification of Monolithic and Al2O3 Fiber-Reinforced Ti2AlC MAX Phase Composites

Materials

Robert Vaßen¹  Jesus Gonzalez-Julian¹  Doris Sebold¹  Rimy Gabriel¹  Olivier Guillon¹  Sylvain Badie¹ 

[1] Institute of Energy and Climate Research, Materials Synthesis and Processing (IEK-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany;

关键词: Ti₂AlC;    MAX phases;    powder injection molding;    ceramic matrix composites;    powder bed sintering;    spark plasma sintering;   

DOI  :  10.3390/ma14133632

来源: DOAJ

【 摘 要 】

Near-net shape components composed of monolithic Ti₂AlC and composites thereof, containing up to 20 vol.% Al₂O₃ fibers, were fabricated by powder injection molding. Fibers were homogeneously dispersed and preferentially oriented, due to flow constriction and shear-induced velocity gradients. After a two-stage debinding procedure, the injection-molded parts were sintered by pressureless sintering at 1250 °C and 1400 °C under argon, leading to relative densities of up to 70% and 92%, respectively. In order to achieve near-complete densification, field assisted sintering technology/spark plasma sintering in a graphite powder bed was used, yielding final relative densities of up to 98.6% and 97.2% for monolithic and composite parts, respectively. While the monolithic parts shrank isotropically, composite assemblies underwent anisotropic densification due to constrained sintering, on account of the ceramic fibers and their specific orientation. No significant increase, either in hardness or in toughness, upon the incorporation of Al₂O₃ fibers was observed. The 20 vol.% Al₂O₃ fiber-reinforced specimen accommodated deformation by producing neat and well-defined pyramidal indents at every load up to a 30 kgf (~294 N).

【 授权许可】

Unknown