The document provides an overview of die casting, focusing on cold chamber and hot chamber processes used with various metal alloys such as aluminum, brass, magnesium, zinc, tin, and lead. It details the advantages and disadvantages of die casting, including production rates, part complexity, and potential defects during the casting process. Additionally, it highlights the application of die casting in manufacturing engine components and other mechanical parts.

1. DIE CASTING
Lecture 3

2. RECAP

3. Courtesy: CustomPartNet
Materials: Aluminum, Brass and Magnesium
COLD CHAMBER DIE CASTING MACHINE

4. COLD CHAMBER DIE CASTING MACHINE
https://slideplayer.com/slide/8962123/

6.  Cold chamber die casting is a type of die casting that is used for alloys with
high melting temperatures (i.e. Aluminum and Magnesium alloys).
 Molten metal is poured into unheated chamber from external melting
container, and a piston injects metal under high pressure into die cavity
 Molten metal is ladled from the furnace into the shot chamber through a
pouring hole.
 High production but not usually as fast as hot - chamber machines because of
pouring step
 Casting metals: aluminum, brass, and magnesium alloys
COLD CHAMBER DIE CASTING MACHINE
https://cwmdiecast.com/2016/05/27/die-casting-101-hot-chamber-vs-cold-chamber/

7. Courtesy: CustomPartNet
Materials: Zinc, Tin and Lead
HOT CHAMBER DIE CASTING MACHINE

8. HOT CHAMBER DIE CASTING MACHINE
https://cwmdiecast.com/2016/05/27/die-casting-101-hot-chamber-vs-cold-chamber/

10.  Hot chamber die casting is a type of die casting that uses alloys with low
melting temperatures (i.e. Zinc, some Magnesium alloys).
 Using alloys with high melting temperatures would result in damage to the
gooseneck, nozzle, and other components.
 Hot-Chamber Die Casting Metal is melted in a container, and a piston
injects liquid metal under high pressure into the die
 High production rates - 500 parts per hour not uncommon
 Applications limited to low melting - point metals that do not chemically
attack plunger and other mechanical components
 Casting metals: zinc, tin, lead, and magnesium
HOT CHAMBER DIE CASTING MACHINE
https://slideplayer.com/slide/8962123/

11. One-piece Die-cast Chassis for a
High-speed Serial Electronic Printer
Die-cast Aluminum Components
Courtesy: Aluminum Industrie Vaasen

12. Materials Properties
Aluminum alloys
• Low density
• Good corrosion resistance
• High thermal and electrical conductivity
• High dimensional stability
• Relatively easy to cast
• Requires use of a cold chamber machine
Copper alloys
• High strength and toughness
• High corrosion and wear resistance
• High dimensional stability
• Highest cost
• Low die life due to high melting temperature
• Requires use of a cold chamber machine
DIE CASTING MATERIALS

13. Magnesium alloys
• Very low density
• High strength-to-weight ratio
• Excellent machinability after casting
• Use of both hot and cold chamber machines
Zinc alloys
• High density
• High ductility
• Good impact strength
• Excellent surface smoothness allowing for painting or plating
• Requires such coating due to susceptibility to corrosion
• Easiest to cast
• Can form very thin walls
• Long die life due to low melting point
• Use of a hot chamber machine
Materials Properties

14. Defect Causes
Flash
• Injection pressure too high
• Clamp force too low
Unfilled sections
• Insufficient shot volume
• Slow injection
• Low pouring temperature
Bubbles
• Injection temperature too high
• Non-uniform cooling rate
Hot tearing • Non-uniform cooling rate
Ejector marks
• Cooling time too short
• Ejection force too high
POSSIBLE DIE CASTING DEFECTS

15. Advantages
 Can produce large parts
 Can form complex shapes
 High strength parts
 Very good surface finish and accuracy
 High production rate
 Low labor cost
 Scrap can be recycled
Disadvantages
 Trimming is required
 High tooling and equipment cost
 Limited die life
 Long lead time
Applications
Engine components : pistons, cylinder heads, and
engine blocks; propellers, gears, bushings, pumps,
and valves
DIE CASTING