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High Production Rate ToolingCase Western Reserve University
David SchwamJohn F. Wallace
Castings for Improved Defense Readiness
NADCA DMC February 2008
Chicago, IL
Objectives
• Production rate determines profitability of metal mold processes. Increasing production rate is therefore a high priority, boosting profits and competitiveness.
• A key aspect of increased production rate is shorter cycle times by faster removal of heat from the casting.
• Advances in modern die steels should allow more aggressive use of cooling line size and distance from the cavity.
• The project will evaluate effectiveness of new cooling line design and provide guidelines that account for higher strength and toughness of advanced die steels.
Needs & Benefits
Benefits to:
• DoD– Shorter production lead times and lower cost
parts for DoD weapon systems
• Industry– Increased profitability and competitiveness
of metal mold casting industry
Process Specifications
IN SIMULATION THIS OCCURS AT THE SAME TIME.
Spray time is:
(5) Seconds on large inserts
(3) seconds on cores
Some additional time:
(5) seconds blow off
(2) seconds wait
Cover Side Cooling Lines – V4
Cover Cores
Green shows cooling line bubblers in cores. Material Water
Cover cooling lines. Material - Oil
Oil lines 157 ºC (300 –325 ºF)
Flow rate of 0.34 m3/hr (1.5 gal/min)
HTC of 500 W/m2K
Water line run at 20 ºC
Flow rate of 0.7 m3/hr. (3.0 gal / min)
HTC of 5500 W/m2K
Shot tip - HTC of 10000 W/m2K
Shot Tip cooling Material – Water Not shown
Die Steel initial temp 300 ºC (600 º F)
Ejector Side Cooling Lines V4
Green shows cooling line bubbler in ejector inserts. Material Water
Ejector cooling lines. Material - Oil
Ejector Runner block cooling lines. Material - Water
Oil lines 157 ºC (300 –325 ºF)
Flow rate of 0.34 m3/hr (1.5 gal/min)
HTC of 500 W/m2K
Water line run at 20 ºC
Flow rate of 0.7 m3/hr. (3.0 gal / min)
HTC of 5500 W/m2KDie Steel initial temp 300 ºC (600 º F)
Section Though Die
Cover die cooling lines
Ejector die bubbler lines.
Ejector die bubbler lines.
COVER SIDE
EJECTOR SIDE
Cover core bubbler lines.
Thermocouple placed in center of the part spaced ½ way between the cores (length wise).
A
B
0.30”
0.50”
Current Design
A= 0.87”
B= 0.69”
Part during solidification V4 (open die at 30 sec.)Click on image
Section though the die steel during solidification V04Click on image
Thermocouple Result During Cycle V04
At 30 seconds thermocouple is 545.6 C
Cover Side Cooling Lines – V5 Cover Cores
Green shows cooling line bubblers in cores. Material Water
Cover cooling lines. Material - Water
Oil lines NONE
Water line run at 20 ºC
Flow rate of 0.7 m3/hr. (3.0 gal / min)
HTC of 5500 W/m2K
Shot tip - HTC of 10000 W/m2K
Shot Tip cooling Material – Water Not shown
Die Steel initial temp 150 ºC (300 º F)
Ejector Side Cooling Lines - V5
Green shows cooling line bubbler in ejector inserts. Material Water
Ejector cooling lines. Material - Water
Ejector Runner block cooling lines. Material - Water
Oil lines NONE
Water line run at 20 ºC
Flow rate of 0.7 m3/hr. (3.0 gal / min)
HTC of 5500 W/m2K
Die Steel initial temp 150 ºC (300 º F)
Section Though Die
Cover die cooling lines
Ejector die bubbler lines.
Ejector die bubbler lines.
COVER SIDE
EJECTOR SIDE
Cover core bubbler lines.
Thermocouple placed in center of the part spaced ½ way between the cores (length wise).
A
B
0.30”
0.50”
Modified Design
A= 0.50”
B= 0.50”
Thermocouple Result During V05
•V5 was run with these conditions.
•Initial Die Steel initial temp 150 ºC (300 º F)
•A and B dimensions changed to 0.500
•A & B lines run with water.23.9 sec
Oil (V04) vs. Water (V05) Comparison
V05 with waterV04 with Oil
TC = 545.6 C @ 30 sec TC = 545.6 C @23.9 sec
Predicted cycle time reduction: 6.1/30=20%
Project and Implementation Plan
• Fabricate and test die casting inserts with larger cooling lines and/or closer to the casting.
• Monitor production of parts and determine new cycle time.
• Evaluate effect of modified cooling line system on die life.
• A good baseline for the study is available from extensive database of previous production.
• Results will be disseminated through NADCA meetings, NADCA publications for industry, and the Metalcasting Congress
Acknowledgements
• AMC’s Castings for Improved Defense Readiness program is sponsored the Armaments Research and Development Engineering Center, Picatinny, NJ and Benet Laboratories, Watervliet, NY.
• The support of St. Clair Die Casting is gratefully acknowledged.
High Production Rate ToolingDLA - POC: Dan Gearing ([email protected], 703-767-1418)
Warfighter Relevance: Increased productivity of metal mold components for weapon systems
• Problem: High cycle times in the production of metal mold castings
• Objective: Evaluate advanced cooling techniques for casting dies in order to reduce cycle times for metal mold castings
• Benefits: 10% reduction in cycle time associated with the production of a die casting
• Reduced production lead time
• Improved productivity
• Reduced operating costs
• Milestones / Deliverables– Revised guideline for cooling line placement
• Transition Plan– The revised guidelines will be added to the NADCA Die
Cooling Systems Engineering Course and accompanying text
Partners:– Case Western Reserve University,
NADCA, St. Clair Die Casting, Premier Tool & Die Casting