Case Western Reserve University

James D Cawley

Arthur H Heuer

Wyatt S Newman

Brian D Kernan

William H Glime

In a process for producing powder metallurgy objects containing two or more individually formed pieces, the individual formed pieces or powder compacts which are comprised of powder and a binder are joined together. A polymer compatible with the binder is sandwiched between two such powder compacts. A lamination joint is formed. The polymer is then softened, and a resultant aggregate body is thermally processed to remove the binder and polymer. The resulting object has no residual interface between the original individually formed pieces. There is no discernable boundary at the lamination joint. The final part is homogeneous and uniform with no foreign material or structural imperfections at the joint.

Process for joining powder metallurgy objects in the green (or brown)

An apparatus for forming an integral three-dimensional object from a plurality of individual laminations includes a cutting surface on which each of the laminations is individually deposited. A concentrated energy source cuts each of the plurality of laminations into a shape required for assembly of the laminations into the integral three-dimensional object. A transfer mechanism removes each of the cut laminations from the cutting surface and stacks each of the cut laminations on an assembly surface. The transfer mechanism includes a gripper face having a peripheral portion and a central portion. A mask is positioned on the gripper face. The mask has an apertured central portion corresponding to the cut lamination. A source of suction communicates with the gripper face and a valve mechanism selectively draws a suction on the gripper face peripheral portion, the gripper face central portion, both or neither. An electronic control device is provided for controlling the operation of the cutting surface, the concentrated energy cutter and the transfer mechanism.

Selective vacuum gripper

A method for manufacturing an integral three dimensional object from laminations includes the steps of fabricating a plurality of first sheets of a first material composition, cutting each of the first sheets to form a contoured layer representing a cross-section of the three dimensional object and to form a waste material and discarding the waste material. The contoured layers are stacked in a desired sequence to form a stack of contoured layers which are then laminated. Subsequently, the contoured layers of the stack are secured to each other to form the integral three dimensional object. This method works particularly well with ceramic material sheets. If desired, a second type of sheet made of a fugitive material can also be cut to form a contoured layer representing a void in a cross-section of the three dimensional object. The contoured layers of the second sheets are then stacked along with the contoured layers of the first sheets to form the object. The laminated stack of contoured layers is then sintered. During processing, fugitive material can be removed, leaving voids in the three dimensional object.

Growing community of inventors

Shaker Heights, OH, United States of America

James D Cawley