You're a mold builder. In a perfect world, you would be able to use one material for every possible project from prototype through production. Everyone would save money; you, your customer and their customer.
That perfect world has arrived in the form of QC-7(R), Alcoa's high strength aluminum mold plate.
First introduced in 1987, QC-7 continues to gain acceptance throughout the plastics industry. Its advantages have been recognized by a wide range of injection and blowmold builders and users producing virtually millions of parts.
Contributing to the success of QC-7 is its high potential to reduce costs for mold builders, mold users and their final customers. But, the brilliant performance of QC-7 doesn't end with just saving money!
QC-7 Reduces Costs, and Improves Productivity
Reduce Production Time
QC-7 aluminum mold plate significantly reduces mold production costs because:
¡EImproved machinability allows cutting speeds up to 40% faster than steel.
¡EGood weldability makes minor changes in mold design and repair of machining errors fast and easy.
¡EFaster finishing reduces polishing time.
¡EYou spend fewer man-hours per mold.
Cut Overhead Costs
QC-7 reduces production overhead costs by:
¡EReducing equipment wear. Its lighter weight and stability reduce equipment wear, so there's less equipment maintenance downtime.
¡EReducing cutting tool wear. Heat developed during machining is largely retained in the chips, so cutting tools stay sharp and last longer.
¡EWeighing less. QC-7 weighs one-third as much as steel, so it's easier and less expensive to handle and transport.
High Thermal Conductivity
QC-7 has four times the thermal conductivity of steel, so using QC-7 reduces cycle time by up to 25%. Because as much as 75% of the heat dissipates in the mold, parts cool more quickly and completely, which allows you to simplify mold design while you improve part quality. Using QC-7 minimizes molded-in stresses due to "hot spots," too. The mold ejects parts closer to room temperature, creating less distortion, warpage and post-mold shrinkage than parts running in steel molds on a comparable cycle.
With its superior thermal conductivity, QC-7 molds heat and cool more quickly than steel molds. As a result, you can cut production costs by reducing energy use and by increasingparts-per-hour with fewer rejections.
YIELD STRENGTH AT ROOM TEMPERATURE AFTER CONSTANT 250¢K EXPOSURE
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80 |  |
QC-7
7075-T651 6061-T651 |
| 70 | |||
| 60 | |||
| 50 | |||
| 40 | |||
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| - | 40 80 120 160 200 240
280 320 360
TIME, HOURS |
Hardness
QC-7 has outstanding hardness for increased mold life. Its consistent hardness, with minimal difference between the surface and center, eliminates problems such as galling or deformation along the parting line.
And, the hardness of QC-7 makes polishing to a mirror-like surface faster and easier. Finishing operations take less time, reducing your production costs.
HARDNESS (Higher Number Indicates Increased Hardness Level)
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AVG. BRINELL HARDNESS QC-7=167HB |
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High Strength
The QC-7 mold plate is up to 54% stronger than 7075 alloy and up to 87% stronger than 6061 alloy. This higher strength is achieved by combining Alcoa-developed alloying technology and manufacturing techniques.
QC-7 superior strength increases durability, resulting in longer mold life. If also allows you to design and manufacture deeper parts from smaller molds. This high strength makes it suitable for use in production injection molds, blowmolds, structured foam molds, RIM molds and aluminum die sets.
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| 80 |  |
QC-7
7075-T651 6061-T651 |
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| 70 | |||
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| 40 | |||
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| - | 1.00 2.00 3.00 *4.00 5.00 **6.00 7.00 ***8.00 | ||
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QC-7 at 4 inch thickness = 87.8% stronger than 6061 |
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QC-7 at 6 inch thickness = 54.2% stronger than 7075 |
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***
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QC-7 at 8 inch thickness = 66.7% stronger than 7075 |
Consistency
Carefully controlled alloying elements and manufacturing techniques make QC-7(R) more consistent throughout the thickness of the plate. By reducing variability in chemical composition, strength and hardness, QC-7 provides outstanding piece-to-piece consistency.
Excellent consistency helps QC-7 improve machinability and finishing. Benching operations are faster, and molds can easily be textured or polished to meet your most demanding surface requirements.
Stability
All QC-7 mold plate is stress relieved to minimize internal stresses and movement during machining, allowing faster machining speeds and fewer set-ups. Because of its stability, you can maintain closer tolerances during rough machining and begin finish machining operations more quickly.
ALUMINUM MOLDS ARE MORE EFFICIENT THAN STEEL MOLDS
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Setting the Standard for Excellence
High-strength QC-7 aluminum mold plate is derived from an alloy and processing technology used extensively in critical aerospace application. Manufacturers use QC-7 to create a wide variety of plastic products including automotive components, computer parts, toys and bottles. Superior in strength, hardness and consistency, QC-7 has the durability you need for longer production runs. You don't need an aluminum mold for prototypes and a steel mold for production any more.
All you need is QC-7(R)
COMPARISON OF MOLD MATERIALS
| MOLD MATERIAL | ADDITIONAL DESCRIPTION | COEFFICIENT
OF EXPANSION
10-6/¢K(SEE NOTE 1) |
THERMAL CONDUCTIVITY(SEE NOTE 2) | DENSITY
LB/CU.IN. |
HARDNESS
(SEE NOTE 3) |
YIELD STRENGTH KSI | WELDABILITY |
| QC-7 | ALUMINUM ALCOA | 12.8 | 91 | .102 | 167HB | 74-79 | NOTE A |
| 7075-T651 | ALUMINUM | 13.1 | 75 | .101 | 150HB | 48-73 | NOTE A |
| 6061-T651 | ALUMINUM | 13.1 | 96 | .098 | 95HB | 40-42 | NOTE B |
| P20 | MOLD STEEL | 7.1 | 20 | .284 | 28-37Rc | 130-135 | NOTE B |
| S7 | ALLOY TOOL STEEL | 6.99 | 21 | .283 | 59-61Rc | 210 | NOTE C |
| H13 | HOTWORK DIE STEEL | 6.1 | 14.4 | .28 | 52-54Rc | 228 | NOTE C |
| 420 | STAINLESS STEEL | 5.7 | 20 | .28 | 52Rc | 215 | NOTE C |
| MOLDMAX(R) | BERYLLIUM COPPER BRUSH WELLMAN | 9.7 | 60-75 | .302 | 30-40Rc | 140-155 | NOTE C |
| AMPCO 940(R) | COPPER AMPCO METAL | 9.7 | 125 | .315 | 210HB | 75 | NOTE D |
Note A¢w¢w Moderately weldable, large repairs should be avoided.
Note B¢w¢w Readily weldable.
Note C¢w¢w Moderately weldable, preheat and post weld heat treat required.
Note D¢w¢w Weldable with proper technology.
Note 1¢w¢w Values are in IN/IN ¢K¢whigher number indicates increased expansion.
Note 2¢w¢w Values are in BTU/ [(Ft.2 Hr ¢K) /Ft.] at 68¢K¢w higher numbers indicate greater Thermal Conductivity.
Note 3¢w¢w HB=Brinell,Rc=Rockwell. Higher numbers indicate increased hardness levels.