Abstract: A method of sintering a 17-4PH alloy powder and a sintered 17-4PH sintered part are disclosed. The part is formed by selective laser sintering a 17-4PH alloy powder and binder mixture to form a green part that is sintered to form a part having a substantially pure martensitic structure. The metal powder includes boron. The sintered part may be further processed by shot peening to improve crack resistance.

Abstract: A method of sintering a 17-4PH alloy powder and a sintered 17-4PH sintered part are disclosed. The part is formed by selective laser sintering a 17-4PH alloy powder and binder mixture to form a green part that is sintered to form a part having a substantially pure martensitic structure. The metal powder includes boron. The sintered part may be further processed by shot peening to improve crack resistance.

Abstract: A set of analytic forms provide empirical data used to determine the material properties of a part following its fabrication. Multiple of families of the forms are identically processed to provide a variety of data, including the reaction of the part material to compression, tension and bending stresses. The forms in each family have a structural feature that singularizes the directional effect of gravity on a test cross section of the material. The dimensions of the test cross section progressively vary within each family so that data can be generated for multiple levels of stress.

Abstract: A method of sintering a 17-4PH alloy powder and a sintered 17-4PH sintered part are disclosed. The part is formed by selective laser sintering a 17-4PH alloy powder and binder mixture to form a green part that is sintered to form a part having a substantially pure martensitic structure. The metal powder includes boron. The sintered part may be further processed by shot peening to improve crack resistance.

Abstract: A set of analytic forms provide empirical data used to determine the material properties of a part following its fabrication. Multiple of families of the forms are identically processed to provide a variety of data, including the reaction of the part material to compression, tension and bending stresses. The forms in each family have a structural feature that singularizes the directional effect of gravity on a test cross section of the material. The dimensions of the test cross section progressively vary within each family so that data can be generated for multiple levels of stress.

Abstract: A reduced feed mechanism for a selective laser sintering machine. The machine includes a powder feed source and a first feed piston to push powder from the source. The mechanism includes a spacer with an interior volume, a second piston, and a seal for the second piston. The spacer fits into the source. The first piston moves the second piston and causes powder to move from the interior volume. Preferably, the pistons are coupled by a floating coupling. An access panel may allow a user to view the coupling. The mechanism may include a ballast which can fit inside the source for the first piston. Preferably, the spacer reduces the volume of powder by approximately 70%. An infrared sensor may also be positioned to view the reduced amount of powder. Methods of selective laser sintering are also provided.

Abstract: A temperature control system for use in a selective laser sintering machine is provided that comprises a thermocouple disposed within a part bed of the selective laser sintering machine and a temperature transmitter in communication with the thermocouple. The temperature transmitter is incorporated into existing control circuitry of the selective laser sintering machine, and the control circuitry is in communication with control logic, which controls the part bed temperature, among other process parameters. In operation, the thermocouple senses and communicates the part bed temperature to the temperature transmitter, and the control circuitry communicates the part bed temperature to the control logic to control part bed temperature during a part build.

Abstract: A method for making an article of syntactic foam includes spreading a layer of a mixture including particulate resin and microballoons across a surface. At least a portion of the mixture is selectively heated so as to cause the portion to assume a desired shape for at least part of the article. The heating is performed Until the resin flows and wets the microballoons to form a solid mass. The method allows a finished part to be fabricated in a single sintering operation with little or no subsequent machining.

Abstract: A temperature control system for use in a selective laser sintering machine is provided that comprises a thermocouple disposed within a part bed of the selective laser sintering machine and a temperature transmitter in communication with the thermocouple. The temperature transmitter is incorporated into existing control circuitry of the selective laser sintering machine, and the control circuitry is in communication with control logic, which controls the part bed temperature, among other process parameters. In operation, the thermocouple senses and communicates the part bed temperature to the temperature transmitter, and the control circuitry communicates the part bed temperature to the control logic to control part bed temperature during a part build.