ADDITIVE MANUFACTURING (3D PRINTING) OF CERAMICS: MICROSTRUCTURE, PROPERTIES, AND PRODUCT EXAMPLES

摘要

Additive manufacturing offers significant advantages (over conventional processing) including enabling design freedom, complex shape capability (e.g. cooling channels), near-net shape capability, the resultant ability to eliminate joining and reduce part count, elimination of some machining, reduced raw material consumption, reduced tooling cost, reduced prototyping and production time, and overall lower cost. However, several challenges have to be overcome to make additive manufacturing a viable production process including achieving the same composition, material properties (static, dynamic, mechanical, physical, chemical, electrical, etc.), isotropy of properties, feature definition, and overall production cost. Also, for some simple shapes (e.g. blocks, ingots) and extremely high volume (100s of thousands/month) small parts, other processes can be more cost effective. In this work, microstructure and properties of additively manufactured (3D printed) reaction bonded (RB) ceramics are presented. The ability to systematically vary process parameters to produce RB ceramics of varying compositions and properties is demonstrated. The properties and microstructures of additively manufactured RB ceramics are compared with the properties and microstructure of the RB ceramics made by conventional processing. Finally, the ability to produce complex-shaped components is demonstrated with some examples.