3d Printing

June 25, 2016

Essay 2

        3D printing has been successfully used to create rapid prototyping, in many different applications. 3D printing is also known as Additive Manufacturing, because it forms objects by adding material instead of subtracting material as we are familiar in traditional manufacturing. Most common materials used for making the parts in additive manufacturing are metals and plastics. The one area in which 3D printing was not able to get in for a while was Ceramic Industry, because the parts manufactured with 3D printing did not meet the high levels of strength and density attained by the conventional way of manufacturing. In 2006 two graduate students, Johannes Benedikt and Johannes Homa, after 4 plus years of research were able to find a way to create ceramic parts with additive printing that are comparable to the ones manufactured with conventional techniques. When they realized that the potential of this technology is high they continued to work on improving it, and in 2011 they started a company named Lithoz GmbH. In this article Monika Homa, the communications officer at Lithoz GmbH, promotes the new patented technology and investigates some new areas that the technology can be used. Additive manufacturing of ceramic parts is using a unique technology, and it creates parts with high precision and density, and can be also used in a wide range of applications.

        Additive manufacturing for creating ceramics parts described in the article is a 2 step^[a] process called Lithography-based ceramic manufacturing (LCM) which is patented by Lithoz GmbH. Homa describes  the LCM technology as “a slurry-based process, where ceramic powder is homogenously dispersed in a photocurable monomer system and selectively polymerized through mask exposure to produce initially the green part. These green parts are basically composites of ceramic particles within a photopolymer matrix, which acts as a binder for ceramic particles. During thermal posttreatment, processors remove the organic matrix via pyrolysis, and particles densify during sintering to give the dense ceramic body.^[b]”(Homa, 24). This 2 step process is mimicking the traditional way of manufacturing, but “the ability to fabricate dense, high-strength parts with complex geometries allows engineers to design parts based on functional requirements rather than design systems around available parts.” (Homa, 23). Additive manufacturing in ceramics industry has been slow

        The LCM technology produces ceramic parts which are precise and have high strength. ^[c]

“The LCM technology process precisely fabricates strong ceramic objects layer-by-layer. A high-resolution optical system controls production of very precise and complex geometries with minimum feature sizes down to 100 μm.” (Homa, 24). Homa claims” Manufactured components also have an excellent surface quality. Unfinished surface roughness for alumina is Ra of ~0.4 μm and for zirconia Ra of ~0.6 μm.”(Homa, 25). The parts are made off the same materials used in the conventional manufacturing and that is how their density and strength are comparable to the parts formed in traditional way. “For example, alumina parts show values of >99.4% theoretical density (>3.96 g/cm3) and four-point bending strength of 430 MPa. Zirconia components show theoretical density of 99.6% and strength of 650 MPa.” (Homa, 24). ^[d]