The Benefits of SB Tech's New ECO Al-Mg Raised Access Flooring
The industrial world uses large amounts of Aluminum (Al) and Magnesium (Mg) alloys because of their relative abundance, good strength-to-weight ratios, and in the case of Aluminum, corrosion resistance. Magnesium, however, has a disadvantage that when in a molten state for casting into products, it will oxidize (burn) on contact with the air. To combat this, manufacturers typically use some type of ‘melt protection’, such as a gas or liquid to isolate the molten surface of the magnesium from ambient air conditions.
Unfortunately, the gas that has become the standard for molten magnesium processing (SF6) has significant environmental disadvantages. While exploring a new environmentally friendly gas-free processing method for molten magnesium, SB Tech developed a new aluminum-magnesium alloy that brings substantial benefits to raised access flooring applications.
In the past, to prevent molten magnesium surface oxidation, salt fluxes or concentrated gasses like sulfur dioxide (SO2) were used as the intermediary between the metal and the ambient air. While these solutions worked, they presented other problems in terms of the quality of the end product, corrosion of process machinery and safety of the workplace. In the 1970’s SF6 was introduced as a melt protection medium and has been in use since. SF6 has the benefit of being relatively non-toxic, is non-flammable and non-corrosive.
Unfortunately, while from an industrial standpoint SF6 works well, it has been identified as a very powerful and very persistent greenhouse gas. For comparison, one standard 115 lb. gas cylinder of SF6 is equivalent to 1,243 tons of CO2 greenhouse gases. Courtesy US EPA
As a result, through both regulation and voluntary reductions, the use of SF6 for magnesium melt protection is being phased out. Fortunately, as with many technological advancements, what appears at first to be a problem has actually become an opportunity!
Studies by Sakamoto et al., 1997 and Wiese et al., 2015* showed that the addition of Calcium (Ca) to normal Magnesium (Mg) produced a melt-composition that was encased by an outer shell of Calcium Oxide (CaO) and an inner layer of both Calcium Oxide (CaO) and Magnesium Oxide (MgO). Other stable variants like Mg/Mg2Ca were observed depending on experimental variations. Ultimately, the formation of these stable outer layers proved to function as a melt protect, preventing process problems in Magnesium without having to introduce an additional blanket layer or liquid.
SB Tech in collaboration with the Korea Institute of Industrial Technology has developed a novel alloy based upon these principles, called ECO Al-Mg.
The Winning Formula
General Composition: Mg(l) (+ Al, and other alloying elements) + CaO(s) → Al2Ca(s) + Mg
This new alloy has several key benefits including:
- Mg SF6 melt problems solved with no harmful green house gases
- Increased strength of the final product
- Safer compositions when mixed with other elements
- Light weight
- Less expensive than alternatives
Magnesium has the lowest density among the most common metal alloys, which makes it a desirable compound to mix into an alloy. Its high molten oxidization rate is now safely and effectively corrected with advancements like the ECO Al-Mg alloy.
Furthermore, ECO Al-Mg is stronger and more durable than Aluminum alone while still carrying the benefits of Aluminum's natural corrosion resistance, light weight, and lower cost.
Given these benefits, the new ECO Al-Mg alloy is proving its mettle in the fabrication of raised metal flooring. When used in floor tiles and related components in traditional applications, such as in semiconductor manufacturing and data centers, field-assembly of flooring systems becomes easier because of the lighter weight of the product.
This new alloy also provides substantial opportunities to extend raised metal flooring into areas where it has traditionally not been applied, including heavy-equipment manufacturing applications. As certain types of manufacturing demand more process flexibility, ECO Al-Mg raised access floors have arrived just in time to bear the load while making a significant economic and environmental impact.
NEHP is excited to be introducing ECO Al-Mg raised access flooring to the North American market.
*Source: Melt Protection of Mg-Al Based Alloys María J. Balart *, Jayesh B. Patel * and Zhongyun Fan BCAST, Brunel University, Uxbridge, Middlesex, UB8 3PH, UK; firstname.lastname@example.org * Correspondence: email@example.com (M.J.B.); firstname.lastname@example.org (J.B.P.); Tel.: +44-1895-267105 (M.J.B. & J.B.P.); Fax: +44-1895-269758 (M.J.B. & J.B.P.) Academic Editor: Hugo Lopez Received: 23 March 2016; Accepted: 23 May 2016; Published: 30 May 2016.
*Cross-Ref: Sakamoto, M.; Akiyama, S.; Ogi, K. Suppression of ignition and burning of molten Mg alloys by Ca bearing stable film. J. Mater. Sci. Lett. 1997, 16, 1048–1050.
*Cross-Ref: Wiese, B.; Mendis, C.L.; Ovri, H.; Reichel, H.-P.; Lorenz, U.; Kainer, K.U.; Hort, N. Role of CaO andCover Gases on Protecting the Cast Surface of Mg. In Proceedings of the 10th International Conference onMagnesium Alloys and Their Applications, Jeju, Korea, 11–16 October 2015; pp. 814–819.