| Abstract Scope |
Laser direction deposition provides a promising method in printing ceramics but poses great challenges in controlling properties due to prevalent cracking issues. In this paper, a systematic study was performed on the effects of processing conditions and compositions on as-fabricated part density, grain size and distribution, crack prevalence and characteristics, and mechanical properties. In particular, doping with different weight percentages of zirconia was found to be an efficient way of controlling microstructure, densification, and cracking. Near fully dense alumina ceramics were successfully fabricated. Zirconia, segregated into grain boundaries, helped toughen the deposited ceramic samples through crack inhibition and suppression. Increased dopants resulted in grain refinement, which was correlated with the fracture strength of the fabricated specimens. The dopants, in combination of controlled high cooling rates, was demonstrated with promising results in controlling cracking issues inherent in laser direct deposition of ceramics and tailoring their mechanical strength. |