presentation by: sachin bhatia - ryerson universityrravindr/common defects on high pressure...
Post on 05-Mar-2018
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TRANSCRIPT
PRESENTATION
BY:
SACHIN BHATIA
� OBJECTIVE
� INTRODUCTION
� DIE CASTING – ADVANTAGES & DISADVANTAGES
� DANA CORP’S THERMAL MANAGEMENT UNIT (TMU)
� HIGH PRESSURE DIE CASTING (HPDC)
� DEFECTS FOR HPDC
� RESULTS & CONCLUSIONS
� Study about High Pressure Die Casting manufacturing process
� Common defects that are encountered with the process
� Conduct some literature reviews to know the cause of the defects
� Compare the literature reviews with the casting manufactured at Dana Corporation
� Provide some results and conclusions to minimize the defects
� Die casting -> metal casting process for producing engineered metal parts
� Non ferrous metals are used like Aluminum and Magnesium
� Highest Volume of mass produced items manufactured
� Can be used for large quantity of small to medium sized components
� Castings have good surface finish and have good dimensional accuracy compared to different casting methods
� Efficient and economical process compared to other manufacturing processes/techniques
� High speed production
� Dimensional Accuracy and stability
� Strength and weight
� Multiple finishing techniques
� Simplified Assembly
� High initial cost
� Limited to high fluidity metals
� Porosity defects
� Large production volume is needed to make the process viable
� Designed and manufactured at Dana Canada Corporation
� More fuel is utilized at the cold phase of the engine compared to when its warm
� TMU heats up the coolant using hot oil from the transmission -> making the engine warm faster and increasing efficiency
� TMU can also be used as a traditional cooler that cools up the coolant once the engine is warm enough
� The TMU has 2 components:
� Active Warmer Unit (AWU)
� Thermal Bypass Valve (TBV)
� AWU is the warmer that warms the coolant initially as required
� TBV is the valve that controls the flow of the coolant between the warmer and cooler
� HPDC is a process wherein the molten metal is pushed through a sleeve using a plunger
� Metal starts with a low velocity and the speed gradually increases in the second and third stage
� Entrapped air / gases are the major contributor to the porosity defects
� There are many defects for HPDC
� Unfilled sections
� Hot tearing
� Ejector marks
� Porosity� Due to Shrinkage
� Due to entrapped gases
� Galvanic Corrosion
� Porosity is the trapped air inside the die casting parts
� 2 kinds� Due to shrinkage
� Due to trapped gases
� Porosity due to shrinkage� Occurs in HPDC
� Voids are formed as metal freezes and shrinks
� Various design techniques are used to avoid this form of defect
� Flexible molds, Chills, Using a Runner/Gate system
� Heating or cooling certain areas would also allow for uniform cooling thus reducing shrinkage porosity
� Porosity due to trapped gases� Occurs in HPDC due to entrapped gases� Gases are created as the molten metal comes in contact with
the lubricants inside the mold� Runners and gates are used to avoid turbulence and entrap
air as the metal gets poured in� Addition of metallic elements such as steels react with gases
to prevent porosity� Vents and vent blocks are used to release the entrapped air� Vacuum also helps in pulling the entrapped air/gases
� The casting designed at dana also encountered porosity as shown in the figure
� The casting designed at dana also encountered galvanic corrosion
� Galvanic corrosion is caused between the aluminum and copper in the A380 alloy used for casting
� The corrosion was affecting the 5052 base plate by decomposing it and causing early failures and leaks
� The galvanic corrosion was eliminated by using a proprietary K-alloy developed by Delphi
� It has minimum copper content < 0.08 wt %
� Can resist salt spray tests for more than 3000 hours
� Research does match with the results of the analysis
� Porosity in castings results because of improper design of the part
� Galvanic corrosion between copper and aluminum within the Al alloy is caused because of improper material selection for casting
� Porosity was eliminated by the redesigning the casting
� Galvanic corrosion was eliminated by changing the material of the casting to a proprietary Aluminum alloy also known as K-alloy manufactured by Dephi
� K-alloy showed massive improvements and testing with 3000+ hours of salt test
� www.dana.com
� "About Die Casting." FAQ. Web. 27 Feb. 2012. <http://www.diecasting.org/faq/>.
� "Die Casting." Web. 27 Feb. 2012. <http://www.efunda.com/processes/metal_processing/die_casting.cfm>.
� "Die Cast Porosity Control: The Part vs. The Process." Sealants and Sealing Services for Metal Castings and Powder Metal Parts, Leak Testing, Cleaning. Web. 27 Feb. 2012. <http://www.impco-inc.com/page215.html>.
� http://delphi.com/manufacturers/dti/available-technologies/engineered-materials-for-license/k-alloy-k-alloy-sp/
� "Advantages and Disadvantages of Die Casting." First-Rate MOLD SOLUTION CO.LTD|Mold Design & Manufacturing. Web. 05 Feb. 2012. <http://www.firstratemold.com/about-us/newsshows/711-advantages-and-disadvantages-of-die-casting.html>.
� www.me.gatech.edu/jonathan.colton/me4210/castdefect.pdf
� http://www.mdwtech.com/kalloy/Diecasting_Engineer.pdf
� www.flow3d.com/pdfs/tp/cast_tp/FloSci-Bib37-11.pdf
� http://optimumdesigntech.com/~midlandt/reducing-gas-porosity-in-high-pressure-die-castings.pdf
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