Abstract: An improved process for the manufacture of uniformly and accurately sized metal spheres, particularly copper spheres, which comprises the steps of classifying a starting lot of spheres into closely sized fractions; separately electroplating each size fraction to a desired final mean diameter and size distribution; and then combining the plated fractions to give a metal sphere product having the requisite mean particles size and size distribution. The electroplating build-up step is characterized by a high level of precision. Additional benefits derive from the high hardness of copper electroplate on relatively soft copper starting particles which facilitates grinding or polishing irregularly shaped plated particles down to the desired sphericity and mean diameter, from the ability of metal such as copper electroplate to cover and envelop contaminated surfaces of starting particles, and from the ability to produce spheres having a unique combination of bulk and surface properties.

Abstract: A process is provided for the manufacture of thin walled ceramic structures, particularly conical or near conical shaped structures. The process involves a tape casting technique wherein a green tape is prepared from a colloidal suspension containing a ceramic powder, a binder system, a plasticizer and a solvent. The suspension is cast into a thin sheet and dried to form a pliable tape. The tape is cut into planar, shaped pieces. Non-planar components of the final structure are preformed from the cut planar tape pieces into predetermined three dimensional shapes. The planar and preformed components are sequentially assembled within a die and compacted under pressure to form a green body. The green body is subjected first, to a burnout cycle to form a brown body, and then sintered to form the unitary, cohesive, thin walled ceramic structure.