Showing papers on "Hydroforming published in 1989"

Analysis of Forming Parts from Advanced Thermoplastic Composite Sheet Materials

Abstract: Thermoforming of advanced thermoplastic composite sheets offers several advantages over traditional processing of these materials, such as tape laying However, some important processing issues have to be resolved before this can become a viable economical process. These include fiber placement control, low cycle times for molding and wrinkle-free complex shape forming.Some of the work that has been reported in the literature so far is reviewed. The major processing considerations that have to be dealt with in going from the design to the thermoforming of a part are discussed. In particular, emphasis is placed on the different processing techniques such as matched-metal forming, hydroforming and diaphragm forming (superplastic aluminum and polymeric) and on material forms such as woven fabrics, angle-plied unidirectional tapes and the newly developed ordered staple formable sheet based on aligned discontinuous fibers. The forming of several shapes using these techniques is presented to illustrate the poten...

Method of making tubular construction parts

Abstract: The invention relates to a method of making tubular construction parts, a tube being formed starting from a sheet and the two ends being welded to one another and the tube thus obtained being subjected to an expanding process The object of the invention is to provide a method of making tubular construction parts with which high-quality tubular construction parts, for example for baking tubes, can be made in a cost-effective and operationally reliable manner The invention essentially consists in the tube being mechanically pre-expanded before the expanding process and in the pre-expanded tube, with its two ends sealed, being subjected in a closed manner to a hydroforming expanding process The advantages achieved consist in particular in the fact that, when the method is used, there is a considerable saving of material with regard to the body to be made and virtually no scrap arises in the course of the manufacturing process Furthermore, low tool costs result for the changeover if various types of tubular construction parts are made There is also no problem in using sheets of the most varied quality, eg normal deep-drawing steel as well as austenitic and ferritic stainless steel Different sheet thicknesses can also be readily processed

Fully hydroformed RF cavities

Abstract: Niobium-coated copper cavities are an attractive solution for RF superconducting structures. The copper parts are usually obtained by spinning and subsequent weldings. However, the defects of welded surfaces may create local coating problems. One way to minimize them is to hydroform monolithic cavities starting from OFHC (oxygen-free high-conductivity) copper tubes. Manufacturing procedures are presented. The very encouraging results obtained on multicell pieces for frequencies of 2.1 GHz and 1.5 GHz are correlated with theoretical computations. Extrapolation to the hundreds of megahertz frequency range is discussed from the technical and financial points of view. On the technical side, the main advantages of hydroforming over the present manufacturing technique are the suppression of the critical welds, a better geometrical accuracy, and better thickness repartition. On the financial side, the proposed fabrication is easier and shorter per cavity and the large initial investment is quickly amortized even in the case of a small series production. >