High Production Rate Tooling Case Western Reserve University David Schwam John 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 m 3 /hr (1.5 gal/min) HTC of 500 W/m 2 K Water line run at 20 ºC Flow rate of 0.7 m 3 /hr. (3.0 gal / min) HTC of 5500 W/m 2 K Shot tip - HTC of W/m 2 K 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 m 3 /hr (1.5 gal/min) HTC of 500 W/m 2 K Water line run at 20 ºC Flow rate of 0.7 m 3 /hr. (3.0 gal / min) HTC of 5500 W/m 2 K Die Steel initial temp 300 ºC (600 º F)

Section Though Die Cover die cooling 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 V04 Click on image

Thermocouple Result During Cycle V04 At 30 seconds thermocouple is  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 m 3 /hr. (3.0 gal / min) HTC of 5500 W/m 2 K Shot tip - HTC of W/m 2 K 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 m 3 /hr. (3.0 gal / min) HTC of 5500 W/m 2 K Die Steel initial temp 150 ºC (300 º F)

Section Though Die Cover die cooling 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 A & B lines run with water sec

Oil (V04) vs. Water (V05) Comparison V05 with waterV04 with Oil TC =  30 secTC =  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 Tooling DLA - POC: Dan Gearing ) 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