permanent mold Flashcards
What are the three permanent mold casting processes?
- die casting
- squeeze casting
- centrifugal casting
It is a permanent mold-casting process in which the molten metal is injected into the mold cavity under high pressure.
die casting
What is die casting?
It is a permanent mold-casting process in which the molten metal is injected into the mold cavity under high pressure.
In die-casting, the molds are called ______
dies
What are the two main types of die casting?
- hot chamber
- cold chamber
In this type of die casting, the metal is melted in a container attached to the machine, and a piston is used to inject the liquid metal under high pressure into the die.
hot chamber die casting
In this type of die-casting, the molten metal is poured into an unheated chamber from an external melting container, and a piston is used to inject the metal under high pressure into the die cavity.
cold chamber die casting
This process is limited in its application to low-melting point metals that do not chemically attack the plunger and other mechanical components.
hot chamber die casting
In hot chamber die casting, the metals it works on are ___________.
zinc
tin
lead
magnesium
What are the advantages of die-casting?
- high production rates
- economical for large production quantities
- close tolerances possible
- good surface finish and dimensional accuracy
- fine grain structure and good mechanical properties are achieved (due to rapid cooling)
- thin wall parts and intricate shapes may be cast (thin sections)
- small size parts may be produced
What are the disadvantages of die casting?
- high initial cost
- not applicable for high melting points
- large parts cannot be cast
- some gases may be entrapped in form of porosity
It is a combination of casting and forging in which molten metal is poured into a preheated lower die, and the upper die is closed to create the mold cavity after solidification begins.
Squeeze casting
What is squeeze casting?
It is a combination of casting and forging in which molten metal is poured into a preheated lower die, and the upper die is closed to create the mold cavity after solidification begins.
Squeeze casting is also known as __________.
liquid- metal forging
What are the advantages of squeeze casting?
- little or no waste material
- complex designs
- fine microstructure with higher strength components
- good surface texture and low level of porosity
- improve performance of lighter alloys
- products have a long service life
- good surface finish
- low shrinkage
- used for both ferrous and non-ferrous alloys
What is the common application for squeeze casting?
automotive parts
What are the disadvantages of squeeze casting?
- high tooling and die cost
- low flexibility of tooling
- accurate control is needed
It refers to several casting methods in which the mold is rotated at high speed so that centrifugal force distributes the molten metal to the outer regions of the die cavity.
Centrifugal casting
What is centrifugal casting?
It refers to several casting methods in which the mold is rotated at high speed so that centrifugal force distributes the molten metal to the outer regions of the die cavity.
What are the three types of centrifugal casting?
- true centrifuge casting
- semi centrifugal casting
- centrifuge casting
In this type of centrifugal casting, the molten metal is poured into a rotating mold to produce a tubular part.
true centrifugal casting
Examples of parts made by true centrifugal casting:
pipes, tubes, bushings, rings
In this type of centrifugal casting, the centrifugal force is used to produce solid castings, rather than tubular parts.
semi centrifugal casting
Example of casting made by semi-centrifugal casting.
wheels and pulleys
