Types of Casting (Youtube)

• Sand Casting

  • perfect for creating large components such as engine block
  • products resulting to rougher surface finish
• Gravity Die Casting

  • employs reusable molds made of sturdy materials such as steel and graphite
  • in this process, molten metal is poured directly into the mold cavity under the influence of gravity
• Gravity Die Casting

  • particularly suitable for materials like, lead, zinc, aluminum, magnesium alloy, bronzes and cast iron
  • gears, gear housing, pipe fitting, wheels, and engine pistons
• 2 Types of Pressure die casting

  • Low Pressure
  • High Pressure
• High Pressure die casting

  • ideal for mass-producing intricate, precise components
• Low pressure die casting

  • ideal for mass producing larger and simpler parts
• Pressure die casting

  • uses high pressure injection of molten metal into the metal mold
  • the molten metal is then solidified rapidly to produce the required product
• Investment Casting (lost-Wax Casting)

  • invests wax patterns w/ refractory materials and binding agent to shape a disposable ceramic mold, then metals are poured to the mold to make castings
• Investment casting

  • Expensive and labor intensive process and can be used for mass production or in complex castings to produce metal casting products
  • gears, biycle trunks, motodisks, spear parts in blasting machine
• Plaster Casting

  • uses a plaster of Paris' mold which cools the metal more slowly allowing for high accuracy especially with thin cross section parts however its not suitable for high temperature ferrous material
• Centrifugal Casting (Rotocasting)

  • industrial method for producing cylindrical parts using centrifugal forces
  • molten metal is poured in pre-heated spinning dye and the centrifugal forces distribute the metal within the dye under high pressure
• 3 variations of centrifugal casting

  • true centrifugal casting
  • semi-centrifugal casting
  • vertical centrifugal casting
• Centrifugal casting

  • produces rotational shapes like cylinders
  • bush bearings, clutch plates, piston rings, cylindrical liners
• Centrifugal casting

  • pouring of the molten metal in the center of the mold in reducing defects such as blowholes shrinkage and gas pockets
  • It is not suitable for all kinds of metal alloys
• Lost-Foam Casting

  • similar to investment casting but uses foam for pattern
  • once the pattern is formed, coating with a refractory ceramic takes place by dipping, coating, spraying or brushing, then the molten metal is poured into the mold to form the desired product
• Lost-Foam Casting

  • suitable for alloys, steel, carbon-steels
  • pump housing, fire hydrants, valves
• Vacuum casting

  • takes place under vacuum pressure to eliminate bubbles and air pockets
  • used for structural chassis components and automotive body parts
• Squeezing Casting

  • hybrid process that merges permanent mold casting and dye forging
  • a specific amount of molten metal alloy is injected into a dye and pressure is applied to shape it, then the metal part is heated over melting temperature and extracted from the dye
• Squeezing Casting

  • ideal for producing safety critical parts in automotive system like space frame joints, aluminum front steering knuckles
• Continuous Casting

  • allows consistent mass production of metal profiles with a constant cross section making it popular in the production of steel bars
• Shell Molding

  • expendable mold casting process
  • it uses a finer sand mixed with resin to create molds
• Shell Molding

  • perfect for producing industrial products like gear box housing, connecting rods, truck hoods, cylindrical heads
• Duration of casting process can vary significantly and affected by the following factors:

  • product's size
  • type of casting
  • production scale
  • labor involved
• Cast metal products (heat treated)

  • known for their durability
  • few months to several decades depends on metal alloy and application
• Advantages of Sand Casting

  • Relatively inexpensive in terms of production costs, especially in low-volume production
  • Processing of metals with high melting temperatures, such as, steel and titanium
  • Recycling ability
  • Casting both ferrous and non ferrous alloys
  • Fabrication of large components
• Disadvantages of Sand Casting

  • Lower degree of accuracy as compared to alternate methods
  • The process yields products with a rough surface finish
  • Difficult to use this method for products with pre-determined size and weight specifications
• Disadvantages of Gravity Die Casting

  • Casting complex objects is difficult
  • At times, the ejection mechanism to remove the casting from the mold forms a dent in the product
  • Manufacturing costs of molds are higher
• Advantages of Gravity Die Casting

  • Provides better surface quality of products due to rapid solidification
  • Production f thin walled products
  • The products possess better mechanical properties
  • Reusable molds save time and incréase productivity which reduces production costs
  • Casting products have high precision and tight tolerance
• Advantages of Pressure Die Casting

  • High precision and dimensional tolerance
  • The process can run for longer hours without the need to replace the die
  • Rapid cooling of molten metal pertaining to faster production rates
  • Reduced need for post-casting machining
  • High efficiency and good product quality
• Disadvantages of Pressure Die Casting

  • Relatively high tool costs
  • Complete setup requires a large capital investment
  • Difficult to ensure the mechanical properties of products, therefore, it is not used for structural parts
  • Limited to non-ferrous materials
• Advantages of Investment Casting

  • It can produce parts with thin walls, more complexity and high surface quality
  • Shrinkage allowance in the mold
  • High dimensional accuracy in products
  • 90-degree angles
  • Due to breaking away of the shell mold, it allows for castings with
  • Can cast hard-to-melt alloys such as stainless steel, thin steel, etc.
  • Reduces the need for post-casting machining
• Disadvantages of Investment Casting

  • Requires labor for use
  • New die requirement for the creation of wax latterns for each casting cycle
  • Higher manufacturing costs of mold
  • Production cycle is longer
• Advantages of Plaster Casting

  • Smooth surface finish
  • The ability to cast complex shapes with thin walls
  • Greater dimensional accuracy than sand casting
• Disadvantages of Pressure Casting

  • The process tends to be more expensive than most casting operations.
  • Unstable material as compared to sand, which can affect the complete process
  • Longer cooling times, effecting production rates
  • Not suitable for high melting materials
  • May require frequent replacements of the plaster molding material
  • Limited applications to aluminum and copper-based alloys
• Advantages of Centrifugal Casting

  • Improved process yields and reduced wastage
  • No requirement of gates and risers
  • The process is convenient to manufacture barrel and sleeve composite metal castings
  • Casting has high density and almost no defects
• Disadvantages of Centrifugal Casting

  • requires high investments
  • Specific shapes production
  • Requirement of skilled labor
• Advantages of Lost Foam Casting

  • High precision casting
  • Economic for high volume production
  • Clean production
  • Allows flexible design
• Disadvantages of Lost Foam Casting

  • High pattern costs for low volume production
  • Many production processes and longer delivery time
  • Low strength causes distortion or damage of the pattern
• Advantages of Vacuum Casting

  • Reduce porosity, improve mechanical properties and surface quality of die casting
  • Diminishes air pockets and bubbles at early stages
  • No requirement for expensive hard tool finishing
  • Suitable for low volume production
  • Welding and heat treatment of products is possible
  • Production of thin walled products
• Disadvantages of Vacuum Casting

  • High tooling cost
  • Potential hollowness issue
  • The mold used in the process has a a short life