Saturday, June 12, 2010

DIFFERENT TYPES OF CASTING PROCESS:

1) Investment casting

2) Permanent mold casting

3) Centrifugal casting

4) Continuous casting

5) Sand casting

Investment casting

Investment casting (known as lost-wax casting in art) is a process that has been practiced for thousands of years, with lost wax process being one of the oldest known metal forming techniques. From 5000 years ago, when bees wax formed the pattern, to today’s high technology waxes, refractory materials and specialist alloys, the castings ensure high quality components are produced with the key benefits of accuracy, repeatability, versatility and integrity.

Investment casting derives its name from the fact that the pattern is invested, or surrounded, with a refractory material. The wax patterns require extreme care for they are not strong enough to withstand forces encountered during the mold making. One advantage of investment casting it that the wax can be reused.

The process is suitable for repeatable production of net shape components, from a variety of different metals and high performance alloys. Although generally used for small castings, this process has been used to produce complete aircraft door frames, with steel castings of up to 300 kg and aluminum castings of up to 30 kg. Compared to other casting processes such as die casting or sand casting it can be an expensive process, however the components that can be produced using investment casting can incorporate intricate contours, and in most cases the components are cast near net shape, so requiring little or no rework once cast.

Permanent mold casting

Permanent mold casting (typically for non-ferrous metals) requires a set-up time on the order of weeks to prepare a steel tool, after which production rates of 5-50 pieces/hr-mold are achieved with an upper mass limit of 9 kg per iron alloy item (cf., up to 135 kg for many nonferrous metal parts) and a lower limit of about 0.1 kg. Steel cavities are coated with a refractory wash of acetylene soot before processing to allow easy removal of the workpiece and promote longer tool life. Permanent molds have a limited life before wearing out. Worn molds require either refinishing or replacement. Cast parts from a permanent mold generally show 20% increase in tensile strength and 30% increase in elongation as compared to the products of sand casting.

The only necessary input is the coating applied regularly. Typically, permanent mold casting is used in forming iron, aluminum, magnesium, and copper based alloys. The process is highly automated.

Sub-types of permanent mold casting

1. Gravity Die Casting.

2. Low pressure die casting.(LPDC)

3. High pressure die casting.(PDC)

Centrifugal casting

Centrifugal casting is both gravity- and pressure-independent since it creates its own force feed using a temporary sand mold held in a spinning chamber at up to 900 N (90 g). Lead time varies with the application. Semi- and true-centrifugal processing permit 30-50 pieces/hr-mold to be produced, with a practical limit for batch processing of approximately 9000 kg total mass with a typical per-item limit of 2.3-4.5 kg.

Industrially, the centrifugal casting of railway wheels was an early application of the method developed by German industrial company Krupp and this capability enabled the rapid growth of the enterprise.

Continuous casting

Continuous casting is a refinement of the casting process for the continuous, high-volume production of metal sections with a constant cross-section. Molten metal is poured into an open-ended, water-cooled copper mold, which allows a 'skin' of solid metal to form over the still-liquid centre. The strand, as it is now called, is withdrawn from the mold and passed into a chamber of rollers and water sprays; the rollers support the thin skin of the strand while the sprays remove heat from the strand, gradually solidifying the strand from the outside in. After solidification, predetermined lengths of the strand are cut off by either mechanical shears or travelling oxyacetylene torches and transferred to further forming processes, or to a stockpile. Cast sizes can range from strip (a few millimeters thick by about five metres wide) to billets (90 to 160 mm square) to slabs (1.25 m wide by 230 mm thick). Sometimes, the strand may undergo an initial hot rolling process before being cut.

Continuous casting is used due to the lower costs associated with continuous production of a standard product, and also increases the quality of the final product. Metals such as steel, copper and aluminium are continuously cast, with steel being the metal with the greatest tonnages cast using this method.

Sand casting

Sand casting is one of the most popular and simplest types of casting that has been used for centuries. Sand casting allows for smaller batches to be made compared to permanent mold casting and a very reasonable cost. Not only does this method allow for manufacturers to create products for a good cost there are other benefits to sand casting such as there are very little size operations. From castings that fit in the palm of your hand to train beds (one casting can create the entire bed for one rail car) it can be done with sand casting. Sand casting also allows for most metals to be cast depending in the the type of sand used for the molds.

Sand casting requires a lead time of days for production at high output rates (1-20 pieces/hr-mold), and is unsurpassed for large-part production. Green (moist) sand has almost no part weight limit, whereas dry sand has a practical part mass limit of 2300-2700 kg. Minimum part weight ranges from 0.075-0.1 kg. The sand is bonded together using clays (as in green sand) or chemical binders, or polymerized oils (such as motor oil.) Sand in most operations can be recycled many times and requires little additional input.

21 comments:

  1. This is Pratik Maru, SEO Web Associate of Thomasnet.com. ThomasNet, powered by Thomas Register® and Thomas Regional®, is an industrial search engine that provides one source for finding the exact product, service, or supplier –quickly and efficiently. ThomasNet provides direct access to the detailed information needed to make a purchasing or specifying decision, including line-item product details, CAD drawings, and more. ThomasNet is brought to you by Thomas Industrial Networksm, a wholly owned subsidiary of Thomas Publishing Company. Thomas has been connecting industrial buyers and suppliers for over 100 years.

    While browsing net, I came across an article on your site and was really impressed. We have interest in collaborating with you and your site to help us spread the good information. I look forward to an email regarding the matter, Thanks!


    Regards,

    Pratik Maru,
    pmaru@thomasnet.com

    ReplyDelete
  2. Trident Steels handles a wide variety of metals, such as stainless steels, wear-resistant steels & so on, to produce top-quality Stainless Steel Investment Castings in all common alloys.

    ReplyDelete
  3. Investment Casting uses a mold that has been produced by surrounding an expendable

    pattern with a refractory slurry that sets at room temperature.
    The pattern (usually of wax or plastic) is then melted or burned out, leaving the mold

    cavity.

    Stainless Steel Casting Products | Investment casting,Precision ...
    Investment casting manufacturer in china
    Hot Reaso,stainless steel investment casting ns for You to Cook With
    die casting manufacturer.investment casting manufacturer ...
    Stainless steel investment casting manufacturers


    for more details
    please contact
    http://www.tridentinvestmentcastings.com/

    ReplyDelete
  4. Interesting blog. It would be great if you can provide more details about it. Thanks you
    Pressure Die Casting Manufacturers

    ReplyDelete
  5. I would really like your post ,it would really explain each and every point clearly well thanks for sharing.

    ReplyDelete
  6. Thank You,I have visited so many blog posts,but your post is really unique.All information you have provided about Casting Moulds.

    ReplyDelete
  7. Trident Steels handles a wide variety of metals, such as stainless steels, wear-resistant steels & so on, to produce top-quality Stainless Steel Investment Castings in all common alloys.
    for more details:
    http://www.tridentinvestmentcastings.com/

    ReplyDelete
  8. thank u after refering it i have got good info on production

    ReplyDelete
  9. Thank you for all the information.Also visit cast iron suppliers in nagpur.

    ReplyDelete
  10. this is an awful website

    ReplyDelete
  11. invest casting is precision & accurate for steel alloy

    ReplyDelete
  12. This article is well written. I could refresh most of the information about casting processes.

    ReplyDelete
  13. its nice but u can include some pictures of these types that may understand it easily..

    ReplyDelete
  14. I have been read so many blogs/Article. but this is really good & very useful I would like to see more article/blogs from yours
    Wear resistant casting manufacturers

    ReplyDelete
  15. The information you've got shared is extremely attention-grabbing. this may extremely useful for shooters. Thanks for sharing such a meaty weblog that basically means that sensible for peoples. we tend to promote such meaty things to audience reach, we tend to simply add a background to market your toil.
    Wear Resistant Casting Manufacturers

    ReplyDelete
  16. Alloy die casting

    Are you looking the best die casting company? We are A die casting manufacturer in china that offers aluminum die casting, magnesium die casting, die casting products.

    ReplyDelete
  17. Nice information. The above are the different types of casting process,Here SAIL TMT Bar have higher strength and ductility for safer construction. It will be available in the length of 12 meters initially in sizes with 8mm-20mm diameter

    ReplyDelete
  18. Nice reading, I love your content. This is really a fantastic and informative post. Keep it up and if you are looking for die casting manufacturers then visit pintuu.com.

    ReplyDelete