Metal die casting - is the process of forcing molten metal under high pressure into mold cavities (which are machined into dies). Most die castings are made from non-ferrous metals, specifically zinc, copper, aluminum, magnesium, lead, and tin based alloys, although ferrous metal die castings are possible.
The die casting method is especially suited for applications where a large quantity of small to medium sized parts is needed with good detail, a fine surface quality and dimensional consistency. This level of versatility has placed die castings among the highest volume products made in the metalworking industry.
Sand casting or a sand molded casting is a cast part produced by forming a mold from a sand mixture and pouring molten liquid metal into the cavity in the mold. The mold is then cooled until the metal has solidified. In the last stage the casting is separated from the mold. There are six steps in this process:
• Allow the metal to cool.
• Break away the sand mold and remove the casting.
• Fill the mold cavity with molten metal.
• Incorporate a gating system.
• Place a pattern in sand to create a mold.
• Remove the pattern.
Investment casting, also called lost-wax casting, is one of the oldest known metal-forming techniques.From 5,000 years ago, when beeswax formed the pattern, to today’s high-technology waxes, refractory materials and specialist alloys, the castings allow the production of components with accuracy, repeatability, versatility and integrity in a variety of metals and high-performance alloys.
Lost foam casting is a modern form of investment casting that eliminates certain steps in the process. The process is generally used for small castings, but has produced complete aircraft door frames,steel castings of up to 300 kg and aluminum castings of up to 30 kg. It is generally more expensive per unit than die casting or sand casting but with lower equipment cost. It can produce complicated shapes that would be difficult or impossible with die casting, yet like that process, it requires little surface finishing and only minor machining
Permanent mold casting is a metal shaping process in which molten metal is introduced into a permanent (reusable) mold, under gravity or low pressure, and held until solidification occurs. The molds are usually coated with a refractory wash and lampblack, which reduces the chilling effect on the metal and [enables] removal of the casting.
In permanent mold casting, metal is used as the mold material instead of sand. Typically cast iron, steel, bronze, graphite, or other metal alloys are treated and formed into two halves of the mold.Some of the products made using permanent mold casting process are housings, fittings, junction boxes, impellers, valve bodies, flanges, manifolds, actuator bodies, compressor parts, electrical parts, electronic bases/housing or covers to name several.
Permanent mold castings, while not as flexible as sand castings in allowing the use of different patterns (different part designs), lower the cost of producing a part. At a production run of 1000 or more parts, permanent mold castings produce a lower piece cost part. Of course, the break-even point depends on the complexity of the part. Complex parts are commonly made
