Effect of slight short fiber aluminosilicate proportion on alumina slurry devoted to additive manufacturing: Rheological behaviour and final properties of sintered materials

Lithography based additive manufacturing (L-AMT) is a widely used additive manufacturing technique for the fabrication of ceramics like Al2O3. Al2O3 shows many favorable properties e.g. high temperature resistance, high hardness, and good corrosion and erosion resistance As a drawback, ceramics are generally brittle, limiting the achievable strength and toughness of the material. One approach to increase fracture toughness is by short fiber reinforcements. The scope of this work focuses on the processing of short aluminosilicate fiber reinforced alumina by lithography based ceramic manufacturing (LCM). As fibers tend to agglomerate when incorporating them into a ceramic slurry, different dispersing additives and amounts were investigated. Using 5 wt% Disperbyk 2155, a slurry containing 1 wt% of aluminosilicate fibers could be processed, showing a viscosity of 11 Pa s at 10 s(-1) and agglomerates of maximal (45 +/- 17) mu m. This viscosity makes the material processable in L-AMT.