Casting process

Casting processes require the highe.st water contents. Such processes are particularly used for the manufacture of nonrotation symmetrical and complicated components. Casting processes can be divided into hollow casting, cored casting and solid casting (see Fig. 5.5-3). 

Casting processes require high water contents. Can be classified into  

Despite widespread development work, plaster of Paris molds are still utilized today due to their excellent absorptive capacity even taking into account the limited reuse of the molds a maximum of 100 castings being possible. 

A particular prerequisite for the success of the casting process is precise control of particular rheological properties of the casting paste, which is achieved by controlling the water content and adding dispersing agents and deflocculants (such as alkali silicates, alkali phosphates, humic acid or tannic acid). 

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To realize a process integrated quality control the conception shown in fig. 2 was followed. The casting process which is influenced by process parameters like thermal economy, alloy composition or black wash will be pursued with particulary to the problematic nature adjusted sensoring systems. On basic factors orientated sensoring systems like microfocus radioscopy, and tomography will be employed and correlated with sensoring systems which can be applicated under industrial conditions. 

Those, on industrial applications orientated systems, are acoustic emission and the temperature analysis of the casting. Realizing this conception (fig. 2) will enable to develop a process parameter control and consequently to stabilize the casting process. 

More difficult it is to analyse and value the acoustic emission signals which are originated from the casting part and the child mold during the casting process (fig. 6 below). Only an... 

Temperature courses of child mold and casting part Acoustic emission signal of the casting process... 

Stegemann, D, Reimche, W. Schmidtbauer, J. Investigations of Light Metal Casting Processes by Real Time Microfocus Radioscopy. The European Journal of Nondestructive Testing, Vol. l,No. 3, S. 107117, Jan. 1992... 

The reflection tomograms (e) show, as expected, solid material in the Plexiglas specimen. A feed head from the casting process is seen clearly in the AZSi-alloy. The diameter of the feed head is about 6 mm in accordance with Fig. 3. 

Beaulne, M. and Milsoulis, E. 1999. Numerical simulation of the fihn casting process. Int. Poly. Proce.ss. XfV, 261-275. 

Rocket propeUants are made mosdy by a casting process as distinct from the extmsion process used to make the very much smaller and more numerous gun propeUant grains (1,2). 

Alloys developed by processing through the investment casting process had high I 5r strength and design flexibiUty, which led to many further ... 

P/M processing of titanium aluminides results in more consistent product quaHty than the conventional casting process, and offers novel alloy/microstmcture possibiHties and improved ductiHty. Processing trends include use of high (1200—1350°C) temperature sintering to improve mechanical properties of steel and stainless steel parts. 

Methacrylate polymerizations are accompanied by the Hberation of a considerable amount of heat and a substantial decrease in volume. Both of these factors strongly influence most manufacturing processes. Excess heat must be dissipated to avoid uncontrolled exothermic polymerizations. Volume changes are particularly important in sheet-casting processes where the mold must compensate for the decreased volume. In general, the percent shrinkage decreases as the size of the alcohol substituent increases on a molar basis, the shrinkage is relatively constant (35). 

Synthetic Marble. Synthetic marble-like resin products are prepared by casting or molding a highly filled monomer mixture or monomer—polymer symp. When only one smooth surface is required, a continuous casting process using only one endless stainless steel belt can be used (52,53). Typically on the order of 60 wt % inorganic filler is used. The inorganic fillers, such as aluminum hydroxide, calcium carbonate, etc, are selected on the basis of cost, and such properties as the translucence, chemical and water resistance, and ease of subsequent fabrication (54,55). 

By a casting process usiag about one-third acryUc resia, usually methyl methacrylate, and two-thirds ATH, iategrated counter top /bowl units and sheet can be fabricated. These marblelike products are very durable, both retaining their initial appearance and having a renewable surface. 

Tape can be cast on a stainless steel table or belt, glass plate, or a Mylar, Teflon, or ceUulose acetate film carrier. The tape should adhere to the carrier sufficiently to prevent curling, but should be easily removable. In a continuous casting process, the tape is dried by air flowing 1—2 m/min counter to the casting direction. A typical dry green tape contains approximately 35 vol % organics, 50% ceramic powder, and 15% porosity. 

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