Lecture 3_Die Casting,sand casting .pptx

Die casting

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/

5. 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/

6. Courtesy: CustomPartNet Materials: Zinc, Tin and Lead Hot Chamber Die Casting Machine

7. Hot Chamber Die Casting Machine https://cwmdiecast.com/2016/05/27/die-casting-101-hot-chamber-vs-cold-chamber/

8. 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/

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

10. 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

11. 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

12. 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

13. 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