*Magnesium Alloys for Sustainable Weight-Saving Approach: A Brief Market Overview, New… DOI: http://dx.doi.org/10.5772/intechopen.102777*

enemy's corridor for several minutes. During the Interwar period, 1919–1939, the interest in strategic magnesium for national armaments industries rose worldwide (**Table 1**). The rise in the magnesium demand was pushed by lightweight structural applications. Alliances were surprised by the German Luftwaffe supremacy of the burning European skies. German airplanes were faster and capable of carrying unexpected bomb shipments. By studying some German planes that crashed, the British discovered that they contained a large percentage of magnesium alloys, the "Elektron metal" as the Germans called it. The weight-saving in German aircraft was the key to such a significant advantage in the European skies. Magnesium was instantly proclaimed as a strategic metal for the second time. The U.S. Government allocated



### **Table 1.**

*History of worldwide magnesium plants before 2000s.*

all of the U.S. nation's total production (at that time produced by Dow Chemical) to national defense. At the beginning of the Second World War, the production of magnesium was 33,500 tons, whereas 5 years later, magnesium production reached a peak of 426,000 tons [1].

Americans developed their own wrought and cast magnesium alloys. Enormous quantities of magnesium were put on military aircraft to curb the weight of liquid and air-cooled engines, wheels, oil tanks, frame structures, instrument housings, gyro frames, and many others. The jet-propelled prototype "Flying Wing" airplane was an aircraft bomber, designed for high speed and maneuverability, made primarily of magnesium (**Figure 1a**). It never entered service in favor of the B-36 bomber (**Figure 1b**) that used a total of 3800 kg of magnesium in castings, forgings, and sheets for airframe parts ad fuselage skin. At the same time, for civilian scope, commercial truck vehicle, body, and motor engine parts, benefited as well from the light-weighting that was made possible by magnesium. Magnesium alloys were extensively used in the airframe skin of the large airplane Convair XC-99 built by the U.S. Air force that remained in activity from the 1940s to 1950s. By 1948, the military aircraft Lockheed F-80C

*Magnesium Alloys for Sustainable Weight-Saving Approach: A Brief Market Overview, New… DOI: http://dx.doi.org/10.5772/intechopen.102777*

**Figure 1.**

*(a) The "Flying Wing" airplane and (b) the B-36 bomber airplane.*

### **Figure 2.**

*The Lockheed F-80C is constructed of magnesium throughout, today visible at the United States Air Force Museum, Ohio.*

"Shooting Star" was the first American project for constructing a combat-ready jet fighter capable of exceeding 500 mph in level flight. One F-80C (47-171) constructed magnesium throughout, redesignated NF-80C-LO, is today visible at the United States Air Force Museum, Ohio (**Figure 2**).

However, following the end of the Second World War, military applications of magnesium lost their strategic importance. The magnesium extractive industry contracted to register a new peak demand in the early '50s because of the Korean War.

The production peak registered during Second World War drawn by U.S. national production was not surpassed until the '70s. Widespread post-war applications of magnesium would be expected in automobiles and civil aircraft to reduce engine weight and dynamic masses. Still, magnesium demand finally decreased till the '70s, not being sustained by aggressive market growth strategies. Magnesium soon revealed losing in front of the prominence of aluminum alloys. The significant factor restricting the growth of magnesium after wartimes can be researched—as a comparison—looking to a good lesson taught by the rival aluminum industry. The primary aluminum industry had a long tradition of cooperation. A group of pioneers in the European aluminum industry set up an "Aluminum Association" way back in 1901,

just 15 years after the modern electrolysis smelting process patents of Charles Martin Hall and Paul Héroult. It was created to promote the widespread use of aluminum (at that time, aluminum was a pioneering material for few applications) to provide economic governance to the nascent aluminum market [2]. The Aluminum Association shared information on markets, feedback from customers on applications, on the quality of the metal. All those information was necessary to align demand requirements and supply features and to encourage the private sector's investments. It was an observatory to analyze the market trends to make the use of aluminum alloys easier. Moreover, the Aluminum Association directed specific actions toward pricing policy based on stable selling prices to promote demand growth. This stability consolidated a nonspeculative market, and it allowed to plan a gradual and programmable extension of the productive capacities of big plants.

These efforts were not completely replicated in the nascent magnesium market to sustain post-war demand. It is true that a prominent American producer, the Dow company, broadened civilian markets by the '1950s. Precisely, the date 1954 was when the Dow company started the mass production of Samsonite Ultralite luggage bag, 20% lighter than other luggage bags, entering in operativity a mammoth large-scale magnesium sheet mill. At that time, several advancements in magnesium alloys were made. New coatings (anodic, electroless-Ni, and Cr-plating) were produced in the 1950s to protect the magnesium alloys from corrosion; viable ceramic and porcelain coatings for magnesium were developed, processes for cladding magnesium sheet and plate alloys with other magnesium alloys and aluminum.

At Dow company, people frequently told that Dow's metallurgists within the 1960s probably had alloyed magnesium with any possible element with good wettability like Li, Al, Si, Ca, Mn, Cu, Zn, Sr, Y, Zr, Ag, and Rare Earth [3]. Researchers soon focused on the overall properties of a fabricated Mg-alloy component as a result of microstructure [4] finally realized by alloy chemistry and processing parameters to promote beneficial solid solution distribution, dispersoids, intermetallic precipitation by heat treatments, grain refining.

Corrosion behavior of Mg alloys developed was enormously improved by limiting impurities Fe, Ni, and Cu that largely influence corrosion resistance of Mg because of the formation (and dispersion) of micro-galvanic cells. New Mg-RE, Mg-Th, and Mg-Th-Zr high-temperature alloys were developed at the beginning of the '60s for use at temperatures of 200–350°C but were limited to their high costs to jet aircraft and military missiles. Following the first hot chamber die-casting process developed at Dow Chemical Company [5], further die-casting techniques were improved and widely used to make engine-driven tools (chain saws, post hole diggers, etc.). Researchers and metallurgy laboratories at magnesium companies provided many answers to questions about phase equilibria, alloying effects, and the relationship of structure and properties for their potential customers (casters, forgers, extruders). During the 1960s in Europe, 20,000–25,000 tons, supplied mainly by Norwegian Norsk Hydro, were being used in the Volkswagen Beetle's air-cooled engine and gearbox. Those components were installed above and behind the rear wheels, and this required the German engineers to produce a drive system as light as possible so that the front wheels gripped the road adequately. The 1960s were also the Cold War years, and several magnesium sheets were used in the lightweight intercontinental ballistic missiles. A machined magnesium-lithium alloy LA 141 was chosen for its high stiffness, low weight, and sound vibration damping characteristics for manufacturing the chassis of the Launch Vehicle Digital Computer (LVDC) that provided the autopilot for the Saturn V, the liquid-fueled rocket developed under the Apollo program for human

*Magnesium Alloys for Sustainable Weight-Saving Approach: A Brief Market Overview, New… DOI: http://dx.doi.org/10.5772/intechopen.102777*

### **Figure 3.**

*The Gemini spacecraft with the centered, white-painted portion in magnesium alloy.*

exploration of the Moon. High-temperature magnesium-thorium alloys in sheet and extrusion form constituted a large part of the large conical structure of the Retro-Rocket Modules of the Gemini spacecraft (the white-painted portions in **Figure 3**, just near the black-painted cone).

However, it was symbolic of what president Roger Wheeler said at the 23rd Annual Meeting of the Magnesium Association (still, International Magnesium Association) in 1966. He said that the magnesium industry had failed in the previous 15 years to take its place as a fundamental industrial commodity metal in the U.S. [6]. At that time, magnesium consumption was one order less than forecast one decade earlier. The Magnesium Association recognized that the future of magnesium growth in North America could depend on the automotive market, and automotive engineers needed to lose their concerns about magnesium, following the example of Germans [7]. In Germany, likewise the air-cooled Volkswagen Beetle die-cast engines, in 1967 Porsche developed the 166 kg crankcase for their six-cylinder 911 series (**Figure 4a**), following visionary forecast in the post-wartime (**Figure 4b**).

By the 1970s, developments were extended to new composite magnesium-based materials, new high-temperature magnesium alloys, new fluxing methods, squeeze casting, recycling methods, and new anodizing processes for magnesium [8]. They were good news for the magnesium industry, but, in reality, in the middle 1970s, world demand for magnesium was about not more than 2% of the aluminum. Economic uncertainties by the oil crisis caused the rapid decrease in sales of the Beetle caused German automakers to curtail magnesium consumption [9]. Despite aluminum pricing that remained steady, the rising magnesium price made aluminum much more competitive. Whether during the late 1970s and beginning 1980s, the need for cutting fuel cost of automobiles could represent an opportunity for the magnesium industry, desulphurization and deoxidation of steel were (unfortunately) still considered the most favorable growth market for magnesium [10]. Magnesium for aluminum alloying was expanding market sector as it consumed almost half of the magnesium production, and it was expected to grow at about 5% per year, while some other markets such as desulphurization and die casting were expected to grow more rapidly [10]. Many efforts were made by researchers to develop high-performance alloys for automotive applications to curb as much weight as possible from massive

**Figure 4.**

*(a) The Porsche 166 kg crankcase for the six-cylinder 911 series; (b) the November 1944 issue of Light Metal Age presented an image of "Tomorrow's light metal car." In the associated article, the writers talk about the use of aluminum and magnesium in the sleek-lined, spaced-aged cars of the future.*

engine blocks, including advanced rapidly solidified magnesium alloys [11] and magnesium alloy composites [12].

Over the second half of the 1980s and early 1990s years, the period was a time of great ferment for magnesium potentialities in the automotive sector [8]. The dominant technology for magnesium production was still electrolysis with giant plants, and the leading producer countries were the United States, Canada, and Norway. Die casting consumption with different magnesium die-cast components in automobile sectors drove the significant annual growth rate of North America—thus more or less the total world magnesium demand at that time. General Motors die-casted in a single-shot, a large part an instrument panel beam for the GMC Savana and Chevrolet Express van. It was a 12 kg part 4 mm thick, which provided 32% mass saving compared to the steel design with improved crashworthiness and high vibration damping. It was less costly thanks to a few parts assemblies, 25 parts in the magnesium design compared to the 67-parts in the steel-made product [13]. To shape much more complex parts made of magnesium, in 1991, the Dow Company registered the Patent for a method and apparatus for the injection molding of magnesium metal, a process based on the foundation of the fundamental discoveries on semi-solid metals by Flemings and his students at Massachusetts Institute of Technology, MIT [14].

During that golden age for magnesium, the US Dow Company increased its almost monopolistic control of the magnesium market thanks to the economy of scale of its giant and old electrolytic plants powered by low-cost power sources available in Texas. In 1991 Dow could produce 109,000 tons per year, namely around 35% of the world's entire output. But the cost of making magnesium in Texas began to rise gradually as the time of cheap natural gas ended. With almost 20 kW-h of electricity to produce a kilogram of magnesium, a lot of power was available, but all that power had been contracted for by the big aluminum producers like Alcoa, Kaiser, and Reynolds [3]. The old Dow plant became soon antiquated, and to stay in business at a competitive level, the most significant World producer would have had to build a new efficient plant, as planned at the Great Salt Lake, a project that never started. Factors leading to Dow's success, and that driven till the early 1990s all magnesium market, have been: early entry, cost efficiency, and strategic deterrence behavior [3]. The biggest world's magnesium producer started to hand over its 60 years of harvests by the early 1970s when Dow began to reap the benefits of its magnesium business rather than investing beyond its old plants in Texas. Dow company switched from a
