Master of Science (MS)
The objective of this research was to manufacture and evaluate three-dimensional (3D) ceramic parts with microstructures, characterize the ceramic injection molding process used for it along with fabrication and evaluation of various mold insert formats, electroplated patterns and X-ray masks used in the process. The patterns were electroplated in nickel on two formats of mold insert substrates. The first format was a modified 1” diameter stainless/tool steel plug suitable for test structures and for complete penetration by melt during injection. The molding was done by CoorsTekâ (Golden CO) as they possessed the required wherewithal and the mold base. The second format consisted of a pair of 3” square nickel plates designed to mount on the standard Battenfeld machines used at CoorsTekâ and at LSU. The patterns for electroplated structures were in three groups. The first group consisted of two patterns for producing ceramic molds with serpentine walls/channels and posts of various geometrical shapes in different sizes. These patterns were electroplated in five different heights of 100 µm, 250 µm, 500 µm, 750 µm and 1000 µm to cover a range of aspect ratios from 0.5 to 20 to characterize the shrinkage and other geometrical variations along the ceramic injection molding process. The second group had concentric ring/disk patterns. These patterns in two different heights of 100 µm & 500 µm produced ceramic disks in two diameters and a ring. The disks were for interference fit and exact fit with the ring. These were assembled and cofired to test the resultant ceramic bond. The third group comprised of patterns for the two sides of a prototype ceramic micro fuel injector. The results from the first two groups were used to mold, machine, drill, assemble and sinter the two sides to yield the required fuel injector. Kapton and graphite were used as membranes for the various X-ray masks used in this research to examine the effects of mask membrane on the sidewall roughness of electroplated nickel structures.
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Palaparti, Dinakar, "Micro molding of 3 D ceramic parts" (2003). LSU Master's Theses. 28.
Michael C. Murphy