Machinists consider Arconic’s MIC-6 the standard for cast aluminum plates owing to its exceptional stability, consistency, and exacting thickness tolerance leading to superior flatness. The consistency of MIC-6 plates is due to casting the plates continuously resulting in a near net thickness in initial production. This is followed by thermal treatment to eliminate internal stresses created within the plate during casting. Finally, the plate is surface ground from its initial near net thickness to its final desired thickness.
MIC-6 is a 7000 series aluminum alloy with zinc as the main element, along with trace amounts of copper, magnesium, iron, silicon, and manganese. These characteristics, along with the thermal treatment of MIC-6, enable high-speed machining with little or no distortion of the plate during the process. The manufacturing process and alloy combined yield aluminum plates with precise control of tolerances and dimensions as well as excellent machining characteristics. Due to these properties, MIC-6 has long been a preferred choice for machining parts and components for precision equipment along with the tooling plate used to support those components during machining. Recent supply chain shortages have left many manufacturers scrambling to find a substitute. Fortunately, metallurgists have developed a range of alloys with similar or even superior characteristics to MIC-6.
Top 4 MIC-6 Alternatives
The most common and frequently used MIC-6 alternatives include Alca-5 from PCP, ACP 5080 from Alimex, K-100S made by Alpase, and ATP 5 made by Vista Metals. All of these are cast aluminum plates with similar properties to MIC-6. They are also all 5000 series aluminum alloys, which is a key weldability difference in MIC-6. This makes them viable alternatives to MIC-6.
Unlike MIC-6 plates that are engineered through a horizontal casting process, Alca-5 plates are built using a vertical direct chill (DC) casting process which leads to a few superior material properties; additionally, no recycled material is used in Alca 5. Alca 5 is used for various applications including construction equipment, machine parts and mounting, index tables, jigs and fixtures, vacuum chambers, and precision applications.
- Lightweight: Alca-5 has a lower density (2.66 g/cm³) than MIC-6. The low weight of the cast aluminum plate helps retain its dimensional stability during fabrication.
- Hardness: The Brinell hardness of Alca-5 is 70 which is slightly higher than that of MIC-6 (65). The hardness of the casting plate resists any permanent or plastic deformation under pressure.
- Ductility: For all the additional hardness, Alca-5 is not a brittle metal. With a tensile yield strength of 18,000 psi compared to MIC-6 15,200 psi, and an elongation at the break of 16% compared to 3% it is substantially more ductile material than MIC-6.
- Width: Compared to MIC-6 which is available at a maximum width of 60.5 inches, precision-milled Alca-5 is available up to a width of 96”.
- Anodizing response: The anodizing properties of MIC-6 are subpar owing to the wide variety of elements used to improve its machinability. In contrast, Alca-5 has an excellent anodizing response due to its porosity-free microstructure and modified alloy composition.
- Weldability: The fair amount of silicon present in MIC-6 plates leads to poor weldability. MIC-6 plates are rarely welded, with MIG opted as the preferred welding process to reduce heat input. Unlike MIC-6, Alca 5 displays very good weldability for both TIG/ MIG and resistance welding.
- Cost savings: Alca-5 has a substantially lower density at .096 lb/in3 than MIC-6 .101 lb/in3. Since aluminum is commonly priced by weight this translates to a significant cost-benefit advantage over MIC-6.
Similar to MIC-6, ACP 5080 is engineered using a horizontal casting process. The double-sided precision-milled ACP 5080 cast aluminum plate has distinct mechanical properties that offer exceptional machinability and makes it a suitable alternative to MIC-6 for applications in the aerospace industry, general engineering, food technology, mold and gauge making, and CNC components
- Anodizing properties: ACP 5080 has a consistent response to anodizing compared to MIC-6 due to an alloy composition that uses less silicon.
- Tensile strength and elongation: ACP 5080 has a typical tensile strength in the range of 240-290 MPa with 15% elongation at break as compared to the relatively low tensile strength of MIC-6 (165 MPa and 3% elongation at break).
- Yield strength: The fine-grain structure of ACP 5080 contributes to its high yield strength (110-130 MPa) as compared to the yield strength (105 MPa) of MIC-6.
- Corrosion resistance: ACP 5080 is alloyed with magnesium to maximize its mechanical properties and corrosion resistance, providing an edge over MIC-6.
- Weldability: ACP 5080 is specially heat-treated, has an excellent coefficient of thermal expansion of 13.5 µin/in-°F, and displays good weldability in contrast to the limited weldability of MIC-6.
- Lower Density: ACP-5080 has a low density equal to Alca-5 at .096 lb/in3 and less than MIC-6 .101 lb/in3. This translates to cost saving on purchases by weight, and savings in transportation as well.
Alpase K-100S cast tooling plate, too, is manufactured using a modified 5083 aluminum alloy in a vertical DC casting process, resulting in its fine-grained structure with minimal internal stresses. The following are some of the superior qualities of K-100S over those of MIC-6 that make K-100S suitable for manufacturing assembly jigs, aircraft parts, vacuum chambers, prototypes, medical instrumentation, automotive tools, and others.
- Micro-structure: The micro-structure of K-100S is virtually porosity free, similar to the micro-structures of Alca 5 and ATP 5 in contrast to the porous microstructure of MIC-6.
- Welding characteristics: Compared to the poor weldability of MIC-6, K-100S has excellent welding characteristics.
- Tensile strength: The tensile strength of K-100S is relatively high (282 MPa) as compared to that of MIC-6 (165 MPa).
- Corrosion resistance: K-100S displays excellent corrosion resistance as compared to the poor corrosion resistance of MIC-6.
- Elongation at break: K-100S has superior elongation properties with 12-15% elongation in 2” whereas MIC-6 has 3% elongation in 2”.
ATP 5 tooling plates are particularly suitable for applications where stringent flatness tolerances and dimensional control are critical. The following properties of ATP 5 make it a preferred alternative to MIC-6 for a range of applications including robotic components, plastic molds, semiconductor and solar manufacturing components, medical testing equipment, packaging machinery, and others.
- Lower density and weight: With a 5% lower density than MIC-6, ATP 5 weighs 5% less than MIC-6, leading to cost savings.
- Higher strength and elongation properties: With a tensile strength of 282 MPa and 15% elongation at break, ATP 5 displays superior strength and elongation properties when compared to MIC-6.
- Superior welding characteristics: Excellent welding characteristics of ATP 5 are in sharp contrast to the poor weldability of MIC-6.
- Anodizing and painting properties: ATP 5 displays a superior anodizing response when compared to MIC-6 and accepts anodized, nickel, and other coatings.
The unique and distinct mechanical, physical, and chemical properties of these MIC-6 alternatives make them suitable for specific applications. Partnering with a trusted metal supplier can help secure a scheduled supply of these alternatives for your production operations.
Partnering With Industrial Metal Service for Sourcing MIC-6 Alternatives
At Industrial Metal Service, we supply new metals like ACP 5080, Alca 5, and others to manufacturers, machinists, fabricators, and hobbyists along with a selection of remnant metals at affordable prices. With our state-of-art aluminum cutting equipment, we can also help you meet your precise dimension requirements without compromising tolerances.