Session: 03-28-01: Joint Session on Recent Advances in Advanced Materials Processing and Tribology

Paper Number: 98967

98967 - 3d Printing and Characterization of Alumina 

Ceramics are notoriously difficult materials to manufacture by means of traditional manufacturing methods due to its high manufacturing cost, required complex machining, low flexibility, and limitations in the geometries a mold can produce. Additive manufacturing is a low-cost scalable manufacturing method that has the potential to solve many of these problems. Additive manufacturing known by multiple names such as 3D printing, Solid Freeform Fabrication (SFF) and Rapid Prototyping (RP) can facilitate the fabrication of complex geometries unable to be achieved by more traditional ceramic manufacturing methods. Various low-cost additive manufacturing methods have been adapted to incorporate various ceramics materials. Most notably in recent years there has been in increased vigor in research of light-based manufacturing methods. The two primary methods studied are Stereolithography based printing and Direct Light Processing (DLP) based printing. Both methods print on a layer-by-layer basis, but DLP printing uses a projected UV light to cure an entire cross section at a time while stereolithography uses a laser to cure each point in a cross section individually before moving onto the next layer. As a result, DLP printing is a faster more economic method to manufacture parts. DLP is a highly sought-after additive manufacturing method to produce complex and dense ceramic parts. Alumina is one of the most studied ceramic materials incorporated in DLP photosensitive resins, due to its superior hardness and wear resistance. Additional properties of alumina include its superior dielectric and thermal shock properties making it a good choice for insulation materials. In addition, it is an inert substance and is insoluble in many chemical reagents at room temperature. Due to the aforementioned properties alumina ceramics have applications in solid oxide fuel cells, orthopedics, biomedical implants, passive components in electronics, abrasive and cutting tools, armor plating and enamel coatings. Most studies employ the use of a unitary spherical particle shape but multiple particle sizes to improve the density, which does little to improve other mechanical properties.  This article, we demonstrate the fabrication of highly dense alumina ceramics parts incorporating multiple particle shapes facilitated using a low-cost Digital Light Processing (DLP) printer. The high solid loading alumina photosensitive resin developed uses a 1:1 ratio by weight of both platelets and nanoparticles. One of the major benefits of the low-cost DLP printer used in this paper is that the resin vat can be heated to a controlled temperature. The heated resin vat reduces the viscosity of the resin during printing, thus improving reflow properties in-between layer prints. Rheological measurements were taken ensuring that the viscosity of the ceramic resin remains within a reasonable range for printing. These rheological measurements represent the effect of both temperature and solid loading on viscosity given a variable shear rate. Thermal post processing was optimized for burnout and sintering, resulting in highly dense ceramic parts. The optimized DLP printing process shows that this scalable additive manufacturing method has the potential to produce low- cost alumina ceramics with improved mechanical properties.

Presenting Author: Majid Minary Arizona State University

Presenting Author Biography: Majid Minary is an Associate Professor at Arizona State University.

Authors:

Majid Minary Arizona State University
Ashley Myles Arizona State University
Adam Griffith Arizona State University