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