Metal Casting Zone Info Blog

Posts Tagged ‘castings’

Information about various Castings Process and Types

Casting history is older than 6000 years. A casting is also known is molding process in which any metal is poured in to the mold. It is one type of manufacturing process in which every metal poured in mold. Generally, casting is uses for creating desired an most intricate of shapes..

Casting can remove other operational processes like machining, forging, and welding. There are different types of casting method or process available today. Generally casting process is divided in to 2 types expendable casting and non-expendable mold casting.Temporary and non-reusable molds are used in expendable casting process. Sand casting, Plaster Casting, Shell Molding, and Investment Castings process are one of the expendable casting processes.

This is oldest metal forming or casting process. Lost wax casting used for to manufacturing of huge parts like turbocharger wheels, golf club heads, elect huge variety of parts ranging from turbocharger wheels to golf club heads, from electronic boxes to hip replacement implants. Lost wax casting used for investment castings. Today investment castings are used for aircraft engine and airframe parts. Lost wax casting is similar to the Lost Foam Casting in which expendable foam patterns are uses for casting productions. Foam pattern is remaining in mold during metal pouring and it’s replaced by molten metal

Die Casting Die casting is one of the non expandable casting process. It’s one type of process in which molten metal is forced under high pressure into mold cavities. In die casting mold dies is used again and again for producing variety of casting size, shape and thickness. Parts, which are manufacturing by die casting are heat resistance and maintaining close tolerances. Die casting produces parts with thinner walls, closer dimensional limits, and smoother surfaces

Sand Casting Sand casting used for make large parts. In sand casting sand used with mold. In sand casting cavity is formed by wood or metal pattern. Using sand casting method, you can cast large iron bell, and alos small automotive parts. In sand casting, two types of sand used like green sand, which is mixture of silica, and olivine sand. Sand casting is uses for high volume production

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Castings without pattern – A new way to produce iron sand castings

Nopatech™ is a new technology developed by Saguenay Foundry. Its purpose is to make very short production runs of gray & ductile iron castings faster and more cost effective by eliminating the need to produce a pattern.

In regular production, patterns are made de create an imprint in a sand mould. Metals are then poured in the “negative” of the part. After cooling, you get a part to the correct dimensions and shape. This technology has been done for hundreds of years to obtain complex shapes that could not otherwise be machine directly in a cost-effective manner.

The problem with patterns is that they are expensive. If you redo the castings dozens or hundreds of even better thousands of time, it can easily be amortized. But in certain situations, one or two castings might be all you need. For instance, prototypes of an unproven design are subject to change after a trial of one or two castings. With a pattern, some change can be made, but not always, so you are always taking a risk.

In this case, a casting that cost 2000$ can require a 5000$ wood pattern do be produced effectively. If you do only one, your casting has cost you 7000$ . Nopatech™ on the other hand might cost you only an extra 1500$ – 2000$ to cast a part without pattern . This is a very substantial gain. The lead time might also go down by half.

To obtain this low cost and fast lead-time, Nopatech™ benefits from the advance in robotic technologies to machine blank sand moulds directly to the final shapes. Cores can also be done, so there is no limit to the complexity of the final shape. Basically, what can be done with wood patterns can be done with Nopatech™.

Also, the quality matches exactly what you get from a casting made with a regular pattern. You reach an average “as cast” RMS figure of 500 and the accuracy of the mould is within 1/16” of an inch, a precision that compares favourably to pattern-made parts. The size limitations is also the same as any other part done at our foundry, with a 115” x 115” maximum flask and a 16,000 lbs gross weight pouring capacity.

Casting ten model cars using a snap flask to make the moulds.

Investment Castings

Investment Casting – 10 Stages of Manufacture

The Lost Wax Investment Castings Process can be used for making Precision Investment Castings in Iron, Steel, Copper or Aluminium Alloys and Aluminium.

The process is almost Identical for each Metal Specification but can vary depending on various requirements in the Investment Casting Industry.

The main benefits are a Precision Investment Casting with closer dimensional tolerances than Sand Casting techniques and exact re-peatability

1)     Construct an Aluminium Die to allow the manufacture of Waxes

2)     Assemble the waxes onto a Runner or Downsprue

3)     Dip the assembly into a Ceramic Slurry

4)     Sprinkle ( by various methods ) grains of a  Refractory Material onto the assembly. Repeat 3 & 4 enough times until you have a thickness of shell to hold the molten metal.

5)     Completely dry the assembly prior to inverting it and placing into a Steam Autoclave to remove the wax.

6)     Place the now hollow assembly or Mould into a Firing Oven to both cure the ceramic and to preheat the mould.

7)     Fill the mould with molten Steel, Iron, Copper Alloy or Aluminium.

8)     Vibrate the Castings inside the assembly to break down the ceramic.

9)     Cut the castings off the assembly, grind where required.

10)Always inspect the castings prior to despatch.

Engineers or Buyers should be aware that there are many technical considerations to be added to these 10 stages. For example the contraction of Iron, Steel, Copper Alloys and Aluminium are different and these factors will have to be considered when making the Tool or Die.

Investment Castings are available at Jade Trading

Metal Castings- Techniques and Applications

Metal castings are idea for complicated and intricate designs that are difficult or unviable by other methods. The best part is that it does not involve the various time- consuming steps like machining, forging, and welding. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods Casting ensures better finish to the products than assembled products and is well suited for a range of metals and alloys.

Sand casting is another type of casting process where molds of sand are used to hold the molten metal. It is one of the most popular methods because of the easy availability of raw materials and cost effectiveness. The molten metal is poured into the cavity made in the shape of the casting to be made. When the molten metal solidifies the mold is broken to remove the castings. These days, chemicals and adhesives are being used to bind the aggregate instead of using the wet sand method because of the low cost factor.

Gravity Die casting is a process in which the molten metal is poured into metallic moulds under gravity without any external pressure, which makes it different from High Pressure Die Casting (HPDC), where the molten metal is  forced into the metal mould under very high pressures. Gravity die casting is used for producing smooth and sharply defined products. This method is well suited for mass production or reproduction, perfect finish and smooth surface. It is faster than other methods like sand casting and the process can also be automated.

Aluminium Castings are popular and versatile techniques for manufacturing semi- or finished products with complicated shapes in industries like automobile and engineering sectors.  Aluminium castings are of two types Ingot casting or Mould casting.  In the former process, aluminium is cast into rolling ingot and wire bar ingot to get semi- and finished products; whereas in mould casting molten metal is poured into specific shaped molds to get products.

The online B2B platforms are great places to get connected with other suppliers and buyers in this product line and also to get updates on international trade fairs, exhibitions and business leads.

Manufacture of Sand Castings

Manufacture of Sand Castings

Engineers have required metal castings for over 5000 years.

As the technical ability of man has progressed, so have the techniques for making a Sand Casting.

Before a foundry can start producing Sand Castings, a number of decisions has to be made regards the Sand Casting Process :

a ) Metal Type

b) Contraction Rate. Ex if the finished product is to be 48″ long, then the pattern / mould cavity, will be approx. 49″long

c) Quality of the finished product, ie manhole cover or Nuclear Submarine part

1)    A pattern is required; this can be made from a cheap timber for single items, or metal for very large quantities.

2)     Cores will be required, if the casting is to have any internal shape

3)    A Foundry Engineer will determine how to ensure the casting is sound.

4)    His final determination is called the Runner System / Method

5)     To form the bottom half of the Mould, sand is now compacted around the bottom half of the pattern.

6)    A joint line is made between the top and bottom half of the mould. 3 dowels or pins are used to ensure the 2 halves of the mould can be put together exactly in the correct position.

7)    Sand is then compacted around the top half of the pattern.

8)    Split the 2 halves of the mould

9)    Carefully take the Pattern out of the sand.

Place any Cores in the mould.

10)   The top and bottom half moulds are clamped or  weighted down

leaving a cavity inside the mould

11) Molten metal is poured down the runner until the mould is full.

12) When cool the casting can be taken out of the mould

For further information on Sand Castings Tolerances please visit jade-trading.com

Introduction for Sand Casting Process with Philip White and Jenny Dunseath in the foundry at Camberwell college of Art London. Video by Chris Follows part of the Process Arts Project – process.arts.ac.uk NOTE: Because the sand is used in a damp condition there is minimal sand dust,and this occurs at the mould face immediately arround the hot metal casting ,clearly visible when the casting is knocked out. At this stage a small watering can or spray will help to stableize this dry material.A standard dust mask could be worn.It is always worth taking sensible precautions with all processes.With sand casting on the scale immagined here keep a water spray handy and use it when cleanig away any dry material. Text Information supplied by Jenny Dunseath: Pattern Making: The Pattern is a full size model of the part that makes an impression in the sand mold, with dimensional allocation for shrinkage and finishing. If the casting is hollow, additional patterns called cores are used to create these cavities in the finished product. Patterns are usually made of wood, plastic, metal, or plaster; however, other materials or combinations of materials are used if there are additional specific properties required of the pattern. Every Pattern must have a draft angle of approximately 2° – 3° to all walls parallel to the parting direction to facilitate removing the part from the mold. Paint the surface of the Pattern with Varnish or Shellac to make it water tight and to ensure that the sand …
Video Rating: 4 / 5

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Castings : Generating Uniqueness and filling needs

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There are many innovative and attractive shapes of different sizes which are present in our homes, shops, organizations etc. Many smart and distinct shapes are fabricated which for the particular usage and application. A funnels which can be taken as instance are used used for fine, smooth and fast transferring of fluids or any other substances from one container to other vessel having smaller opening. The use of funnel can avoid spillage. Casting operations have created such magnificent shapes. List for such kind of substances which are furnished using castings are endless.

Castings’ applications are benefiting many commercial activities and processes. The creations are useful objects which are of great advantages. The urge to look for ways and options which can save the efforts of human have given birth to creativeness to discover things and the result for which is aluminum casting. Casting is the process in which liquid matter is poured into the hollow cavity molds that are of different shapes. The mold is then kept for sometime which after solidifying take the shape of the structure and the cooled matter can then be carefully removed off from the mold.

The industrial scenario is dominated by few major casting processes of which are extensively used in the industries for creating objects for various purposes. Though there are several processes, but metal casting is highly preferred operation for many manufacturing processes which are also laced with numerous advantages.

Being the third most commonly found metal, Aluminum is extensively used for creating several items. From the beginning of 19th century aluminum castings made up roaring development in the aluminium industry at global aluminum industry. The items which are fabricated using aluminum reflect novelty and beauty along with functionality. Aluminum castings application are not just limited to particular usage but have also propagated to various fields of engineering.

The intelligent minds have also devised another method which is Gravity die casting. This one ismanufacturing process which have capability to fabricate the accurately dimensioned, precisely defined, smooth or textured surface parts. In this entire procedure the liquid metal is positioned into metallic molds without caring about the external pressure. Gravity make the molten material to properly house the cavity. This type die casting vary from pressure die casting, in this the molten metal is injected into the molds under force of very high pressure. The outcome differ in the sense that the products has better dimensional accuracy and surface finish.

The another highly practiced methods across the globe is sand casting. Binders have big hand to play in the whole process which are acknowledged for managing the shape of the mold. There are numerous range of binders which are brought into usage of sand casting process. Largest casting sizes and low cost method make it more preferable over other casting processes. Less waste is produced during the entire techniques.

Casting sectors are being refined with the new foundries and inventions which are uplifting the process. Blast furnaces have also invited many benefits with their characteristics. Various methods of casting have to acknowledged for producing beautiful and innovative shapes. Technology has also played its own role in revolutionizing the face of this sector.

Aluminum die casting automated robotic cell using a kawasaki robot and auto ladle to produce a die cast part. This video shows the die cast process including pouring molten aluminum and automatic extraction of the die casting. Premier Die Casting is located in New Jersey. Web site is www.diecasting.com. Phone is 800-394-3006: call us for die casting design assistance.

More Aluminium Pressure Die Casting Articles

Introduction to Steel Castings

Steel casting is a kind of process which involves casting of various types of steel. Steel castings are mainly used when cast irons can’t provide enough strength and stun resistance. Hydroelectric turbine wheels, forging presses, gears, railroad truck frames, valve bodies, pump castings, mining machinery, marine equipment and engine castings are some of the example of high level steel castings.

Steel Castings are mainly categorized into two groups as Carbon Steels and Alloy Steels:

Carbon steel is one with main alloying constituent is Carbon. The American Iron and Steel Institute (AISI) defines carbon steel as: “Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 percent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60.”

The term “carbon steel” may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels. Steel with a low carbon content has properties similar to iron. As the carbon content rises, the metal becomes harder and stronger but less ductile and more difficult to weld. In general, higher carbon content lowers the melting point and its temperature resistance. Carbon content influences the yield strength of steel because carbon atoms fit into the interstitial crystalline lattice sites of the body-centered cubic (BCC) arrangement of the iron atoms. The interstitial carbon reduces the mobility of dislocations, which in turn has a hardening effect on the iron. To get dislocations to move, a high enough stress level must be applied in order for the dislocations to “break away”. This is because the interstitial carbon atoms cause some of the iron BCC lattice cells to distort.

1st of 5 in a video series featuring a simple evaluation comparing wheel impact absorption between an 8×2 polyurethane on cast iron core and Durastar’s 8×2 polyurethane on glass-filled nylon (fiberglass) core. This video features 26 of 87 hits to destroy this wheel. www.durastarcasters.com

Casting ten model cars using a snap flask to make the moulds.