LLC “Zakamskaya Casting Company” is working on ecologically clean, industrial technology of obtaining castings of high accuracy and complexity – Casting on gasified models (LOST-FOAM). Having equipment which allows to obtain high-quality castings of steel (GOST 977-88), grey iron(1412-85), high-strength cast iron (GOST 7293-85), and special alloys according to customer's requirement.Technical characteristics of the castings:
- - surface finish Rz 40;
- - accuracy in size and weight to 8 class (GOST 26645-85)
THE TECHNOLOGICAL PROCESS
Modern high-precision equipment, which has LLC “Zakamskaya Casting Company”, allows to produce the most popular castings of any complexity:
- -cast iron (grey /high-strength cast iron, high alloyed of cast iron brand);
- -steel (carbon/ low alloyed / high alloyed steel grades);
- -alloys based on Nickel (Nikodim, nikarin);
- -special alloys (according to technical conditions of the customer).
For the production of castings with raised mechanical characteristics, we are using materials with different chemical properties. Specifications of all grades of metals that we use for product production, you can see under ALLOYS section.
Let us consider the main stages of production of castings:
1. PRODUCING OF MODELS
At this stage, the most important task is to obtain the polystyrene models in accordance with Customer's drawings.
Producing of model in LOST-FOAM-technology is the most time consuming and responsible part of the whole technological process of production of castings. The quality of model from froth, its geometrical precision determines the quality of cast detail.
For the manufacture of thin-walled models of complex configuration is used polystyrene with a pellet size of 0.3-0.5 mm In mass production the models are made of expanded polystyrene in two stages. At the first stage granules of the original polystyrene foam frothing to a predetermined bulk mass and aged for a certain time for maturation. In the second stage is carried out heating of the expanded granules in a closed volume of the mold, as a result, get formation of the model with given technological and mechanical properties.
The polystyrene which is used for the manufacture of gasified models, are subjected control, as the granulometric texture of the polystyrene has essential for obtaining models with high-quality surface.
The finished models are assembled in blocks (bushes). Finishing before the forming of model unit is applying of non-stick coating to which the LOST-FOAM is subject to special requirements arising from the production technology of castings and processes which are take place in the forms when you fill them by the metal. Non-stick coating is applied to a model surface by dipping or dousing.
Prepared blocks are molded in a special flask, the next, important operation, providing receiving of geometric shape of the casting predetermined shape. Forming of models are made on vibro table. Under influence of vertical and horizontal vibrations, of quartz sand fills all the cavities and channels of models. At our production we use a vibrating table of own design and production.
After the sand will fill all technological cavities, is held by vacuuming – which ensures the strength of the sand and allows to navigate directly to the fill.
Filling of the flasks takes place directly into the shapes of polystyrene. Red-hot metal when come into contact with Styrofoam, gasify it, fills the form. Allocates gases are removed through sand vacuum system.
Metal accurately reproduces the shape of polystyrene block with models. In the future, the castings are cooled from several minutes to several hours, depending on mass of details, thickness of the casting and the technical conditions stipulated technological process.
5. FINAL OPERATIONAL DEVELOPMENT
Produced parts are removed from the flask, separated from the Gating system and shot-blasting drum, get cleaned from the non-stick coating.
Due to strict quality control at every stage of the production process, we get castings in strict accordance with Customer's drawings.
THE ADVANTAGES OF THE LOST-FOAM METHOD
QUALITYThe level of modern production machine tool industry, mechanical engineering, and other technical industries are require high quality items. Parts made by casting on gasified models, fully respond the high technical characteristics. It's all in the features of this method of casting:
- - filling the form with metal occurs under negative pressure, that is metal, under the influence of vacuum, as if "sucked in", making the structure becoming much tighter;
- - the possibility of obtaining the geometry of the castings of high complexity without the use of rods;
- - no displacement of the connectors in the manufacture of the model and during molding;
- - the metal is not in contact with the surface of the form, which is inevitable with the traditional method of casting in sand-clay molds;
LOST-FOAM technology allows to produce castings roughness ..3,2 6,3; accurate to 8 class according to GOST 26645-85.
HIGH FABRICABILITY OF PRODUCED DETAILS
1. Casting on gasified models can be characterized as a high technological method. Through his use of you can get parts of high precision, complex geometric shapes without additional processing, exactly as provided the drawings of the Customers. LOST-FOAM in serial and mass productions is applied for receiving castings of 3-5 grades of complexity, which are characterized having a flat curved outer surfaces, threadolet, flanges with holes, dimples of complex configuration, the internal cavities of the closed or semi-closed type with curved surfaces, whereas by the traditional method to receive such a complicated castings is simply impossible.
2. Unlike traditional methods, LOST-FOAM allows to obtain in the castings technological holes and cavity, specified in drawings, which allow to eliminate completely or minimize the cost of subsequent processing.
3. Up to 90% lower machining allowance for processing, since the casting defects are minimized. Decreases the weight of the casting, because casting is not required foundry bias (or use minimal).
4. Due to the high precision of castings and minimal final machining, cost of auxiliary materials and labor costs are reduced.
The customers highly appreciate the technological production process, high quality of produced parts and their exact compliance with the provided drawings. The finished products differed of high characteristics.
The method has almost no harmful impact on the environment, as for the fabrication of forms are not used toxic materials and resins and production is almost waste-free.
|Carbonic oxide, kg||250||-|
|Sulphur oxide, kg||1,5-2||0,2-0,3|
|Solid waste, kg||1200-1500||0,05 — 0,1|
|Wasted water, m3||0,3-0,5||-|
Usage of technology of casting on gasified models the worldwide justified not only by the high quality of the products, but also a minimum impact on the environment.
Impacts are due to different production methods and different materials for making forms for casting.
In traditional foundry production for manufacturing molds and cores are used binder materials and synthetic resins, which when pouring allocating toxic substances to the air of industrial premises. In the future air purification is quite difficult measure
In the casting process of gasified models for obtaining castings is used polystyrene, and for filling the flasks - quartz sand. Polystyrene, in the process of burning off completely decomposes into gaseous constituents. Since of the flask with models for fill are connected to a vacuum system, all harmful gases are supplied to a purification system, almost not falling into the rooms.
Casting on gasified models is accepted to attributed usually to low-waste production. For example: quartz sand is used in production repeatedly, returning to the forming after cooling and careful sifting. The non-stick coatings used for coating model blocks, gases and dust are removed from sand by sieving. Several times a year we are cleaning sand method of thermal regeneration. To remove dust at the production territory are installed and used suction plant and cyclones with a high degree of purification.