RHEOCASTING PROCESS PDF

This article illustrates various rheocasting processes. These include new rheocasting, semisolid rheocasting, subliquidus casting, rheo-diecasting, swirled enthalpy equilibration device process, slurry-on-demand process, and continuous rheoconversion processes. Pan, Diran Apelian, John Jorstad, Jorstad, Raymond W. Monroe, Mahi Sahoo, Thomas E.

Author:JoJozahn Tygogal
Country:Bhutan
Language:English (Spanish)
Genre:Photos
Published (Last):1 April 2011
Pages:79
PDF File Size:13.36 Mb
ePub File Size:13.10 Mb
ISBN:937-9-50874-437-7
Downloads:24626
Price:Free* [*Free Regsitration Required]
Uploader:Mubar



Semi-solid metal casting SSM is a near net shape variant of die casting. The process combines the advantages of casting and forging. The process is named after the fluid property thixotropy , which is the phenomenon that allows this process to work. Simply, thixotropic fluids flow when sheared, but thicken when standing. SIMA refers to a specialized process to prepare aluminum alloys for thixocasting using hot and cold working. SSM is done at a temperature that puts the metal between its liquidus and solidus temperature.

The semi-solid mixture must have a low viscosity to be usable, and to reach this low viscosity the material needs a globular primary surrounded by the liquid phase. Semi-solid casting is typically used for high-end applications.

For aluminum alloys, typical parts include structural medical and aerospace parts, pressure containing parts, defense parts, engine mounts, air manifold sensor harnesses, engine blocks, and oil pump filter housings.

There are a number of different techniques to produce semi-solid castings. For aluminum alloys the more common processes are thixocasting and rheocasting. With magnesium alloys, the most common process is molding. Thixocasting utilizes a pre-cast billet with a non-dendritic microstructure that is normally produced by vigorously stirring the melt as the bar is being cast. Induction heating is normally used to re-heat the billets to the semi-solid temperature range, and die casting machines are used to inject the semi-solid material into hardened steel dies.

Thixocasting is being performed commercially in North America, Europe and Asia. Thixocasting has the ability to produce extremely high quality components due to the product consistency that results from using pre-cast billet that is manufactured under the same ideal continuous processing conditions that are employed to make forging or rolling stock.

Other disadvantages include a limited number of alloys, and scrap cannot be directly reused. Unlike thixocasting, which re-heats a billet, rheocasting develops the semi-solid slurry from the molten metal produced in a typical die casting furnace. However, rheocasting also poses process control issues such that after an initial surge of activity, very little material is processed via rheocasting.

For magnesium alloys, thixomolding uses a machine similar to injection molding. In a single step process, room temperature magnesium alloy chips are fed into the back end of a heated barrel through a volumetric feeder. The barrel is maintained under an argon atmosphere to prevent oxidation of the magnesium chips. A screw conveyor located inside the barrel feeds the magnesium chips forward as they are heated into the semi-solid temperature range.

The screw rotation provides the necessary shearing force to generate the globular structure needed for semi-solid casting. Once enough slurry has accumulated, the screw moves forward to inject the slurry into a steel die.

As it nears the solidus temperature the grains recrystallize to form a fine grain structure. After the solidus temperature is passed the grain boundaries melt to form the SSM microstructure. For this method to work the material should be extruded or cold rolled in the half-hard tempered state. The advantages of semi-solid casting are as follows: [11]. High consolidation pressures are used to produce high integrity parts and temperatures required to die cast semi-solid metal are lower than normal casting, conventionla tool steel materials are typically used in production applications.

The lack of suitable high temperature die materials limits the casting of high melting point metals, such as tool steel and stellite only to experimantal applications. Other advantages include: easily automated, consistent, production rates are equal to or better than die casting rates, no air entrapment, low shrinkage rates, and uniform microstructure.

Because thixotropy semi-solid state is a middle state in physical or rheological sense, this process is very sensitive to conditions like ambient temperature. Thus production facilities require a higher degree of control over process conditions, demanding more expensive equipment and better operator training. From Wikipedia, the free encyclopedia. Retrieved Kapranos, Proc.

Midson, Robert K. Kilbert, Stephen E. Forming , fabrication , and finishing. Fabrication Piece work Sheet metal. Brazing Crimping Riveting Soldering Welding. Machining and computing. Heat-affected zone Photokeratitis Residual stress Weldability.

Authority control GND : Categories : Casting manufacturing Metalworking. Hidden categories: Wikipedia articles with GND identifiers. Namespaces Article Talk. Views Read Edit View history. Contribute Help Community portal Recent changes Upload file. By using this site, you agree to the Terms of Use and Privacy Policy.

GND :

GEOMETRIA CLEMENS PDF

The Commercial Breakthrough of Rheocasting

Ion Plasma Nitriding. DataPLUS, a new module providing data subsets covering joints information, lubricants and coolants, material dimensions, tribology, and coatings information helps drive even more accurate material selections! Click here to see more. Total Materia New Application Launch! Total Materia has allowed us to solve in a definite way all problems we had for the search of alternate materials in foreign countries. Thanks to Total Materia we have issued real "international" specs for purchase of steels in foreign countries.

BRUCIATA VIVA SUAD PDF

The Rheo Casting Process

Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. See our User Agreement and Privacy Policy. See our Privacy Policy and User Agreement for details. Published on Feb 24, Prsesnted by Satyaranjan Pattanayak.

DSA4 HELDENBOGEN PDF

Semi-solid metal casting

Semi-solid metal casting SSM is a near net shape variant of die casting. The process combines the advantages of casting and forging. The process is named after the fluid property thixotropy , which is the phenomenon that allows this process to work. Simply, thixotropic fluids flow when sheared, but thicken when standing. SIMA refers to a specialized process to prepare aluminum alloys for thixocasting using hot and cold working. SSM is done at a temperature that puts the metal between its liquidus and solidus temperature.

AAM AADMI PARTY MANIFESTO PDF

.

Related Articles