Manufacturing & Prototyping

Digital Preassembly Process

Assembly of major elements of large structures is simulated in a CAD environment. Because the International Space Station is being assembled in orbit, there was a need to verify in advance that it could, indeed, be assembled there and that the various assembled parts would function as intended. A digital preassembly process was devised to satisfy this need for verification, without having to perform assembly on Earth. The process enables designers to simulate the assembly of major elements of large structures by use of a computer-aided design (CAD) system. The process could also be applied in any type of manufacturing and in many types of construction.

Posted in: Manufacturing & Prototyping, Briefs

Read More >>

Punches and Dies for Rounding Corners of Metal Sheets

Corners can be formed to desired radii without sawing, snipping, or filing. Punch-and-die sets have been designed for use in rounding corners of rectangular metal sheets to specified radii. One of the traditional procedures for rounding a corner on a rectangular metal sheet is to first make a rough cut with a band saw and/or hand metal snips, then to file the roughly cut edge; this procedure is time-consuming and does not result in an accurate radius. The use of a punch-and-die set of the present type takes less time and results in a corner with an accurate radius.

Posted in: Manufacturing & Prototyping, Briefs, TSP

Read More >>

Expendable Composite-Layup Dies From Rapid-Prototype Masters

Small production runs of intricate parts can be accomplished at relatively low cost. A method that exploits rapid prototyping has been conceived to reduce the time and cost associated with the production of small quantities of composite-material parts that have complex shapes. In this method, mandrels and dies used in forming composite layups are sized and shaped by molding them on rapid-prototype masters and are made of disintegrating mold material (DMM). The method is particularly suitable for manufacturing ventilating air ducts and water ducts for the International Space Station and manifolds and ducts for low-temperature [

Posted in: Manufacturing & Prototyping, Briefs

Read More >>

Hermetic Wafer Bonding by Use of Microwave Heating

Clamping is unnecessary, and the only appreciable heating occurs in the metal bond. Microwave heating is the basis of a simple technique for quickly and gently bonding two metallized dielectric or semiconductor wafers to each other. The technique can be used, for example, to bond a flat, gold-coated silicon wafer to another gold-coated silicon wafer that is flat except for a cavity, in order to hermetically seal the cavity (see figure). The technique has the potential to become a standard one for bonding in the fabrication of microelectromechanical systems (MEMS).

Posted in: Manufacturing & Prototyping, Briefs, TSP

Read More >>

Chemical Machining of Microscopic Holes and Grooves in Glass

This technique overcomes disadvantages of conventional macro- and micromachining. A technique for making precise, microscopic holes and grooves in glass workpieces has been invented. The technique differs from both (1) traditional macroscopic mechanical drilling and milling and (2) conventional micromachining that involves etching through photolithographically patterned masks. The technique can be used, for example, to make holes between 20 µm and 1 mm in diameter.

Posted in: Manufacturing & Prototyping, Briefs

Read More >>

Tool for Installing a Seal Ring Between Pipe Flanges

Sealing surfaces are kept clean and injuries to fingertips are prevented. A tool has been devised to facilitate the accurate placement of a seal ring between the hubs of two pipe flanges that are to be clamped together. Heretofore, technicians have resorted to impro- visations that have included, variously, insertion of a ring with fingertips, lowering a ring into place by use of string or tape, sticking a ring to one hub by use of grease while the other hub is brought into alignment, and/or positioning a ring by use of a screwdriver or knife. All of these improvisations entail susceptibility to incorrect placement of the ring and contamination of sealing surfaces. Moreover, by inserting fingertips in the narrow pinch gap between the hubs, a technician risks injury.

Posted in: Manufacturing & Prototyping, Briefs, TSP

Read More >>

Weld Repair of a Directionally Solidified Superalloy Article

The weld is also directionally solidified to preserve the desired grain structure. An arc-welding technique for repair of a directionally solidified (DS) nickel-base superalloy article (e.g., a turbine blade or vane) has been devised. The technique equally is applicable to a part as cast or a part that has been damaged in use. Unlike ordinary gas tungsten arc (GTA) welding, this technique results in a predominantly DS microstructure in the repaired region, similar to the microstructure of the DS casting. In addition, whereas ordinary GTA welding often involves the use of a filler material different from that of the workpiece, the weld filler material used in the present technique is of the same composition as that of the DS casting, so that undesired localized chemical differences are not introduced into in the repair region.

Posted in: Manufacturing & Prototyping, Briefs, TSP

Read More >>