Named after the Titans in Greek mythology, the element titanium hasbeen known to exist since the late 18th Century. The technologicaldevelopment and application of the metal and its alloys, however, haveonly been making significant advancements in the US since the end ofWorld War II. For the past 60 years or so, US industry, academia andgovernment have been engaged in efforts to unravel the refining and fabricationproblems posed by this metal, whichholds several promising properties and characteristics.Processing titanium was a particular challenge,partly because the metal becomes verychemically active at elevated temperatures. Oneof the more notable achievements in the advancementof titanium fabrication technology was thedevelopment of rammed graphite casting. Thiscasting process, which is the subject of the featurearticle in this issue, has been in use for more thanhalf a century.The properties of titanium remained somewhatof a mystery into the early part of the 1900s. Forexample, it was initially believed to have a meltingpoint greater than 6000°F. The General ElectricCompany looked into using the pure metal formfor lamp filaments to replace carbon. This pursuitwas dropped when it was determined that theactual melting point of nearly pure titanium was approximately 3000°F,and the company settled on tungsten instead. In addition, there were severalattempts to develop a large scale process for reducing pure titaniumfrom its naturally occurring ore form. It took until the middle part of the20th Century before a commercial scale process was developed for producingraw titanium stock. By the mid-1950s titanium production grewto significant levels. Ever since, the production of titanium has been dictatedby the demands of the aerospace and defense industries, which cyclethrough highs and lows. The significant technological advancements forthe metal and its alloys have also traditionally been driven by the aerospaceand defense industries.This past spring I came across a historical relic that was very influentialin the development of titanium technology. At the conclusion ofthe Aging Aircraft Conference in Palm Springs, California, I drove toPalmdale to visit my brother and sister-in-law. (Palmdale is a small city inAntelope Valley, which is on the western edge of the Mojave Desert andthe home of Lockheed Martin’s famous Skunk Works ® *.) While theremy brother and I went to Blackbird Airpark, a relatively small, outdooraircraft museum that is now the home of a few very historicaircraft. Among the notable aircraft on display was the A-12 #60-6924,the first A-12 ever flown. The A-12 aircraft (the original Blackbird andpredecessor of the more famous SR-71) was developed in the late 1950sand early 1960s for the Central Intelligence Agency (CIA) under a highlysecret program, Project OXCART; it was designed as a potential replacementfor the U-2, a high-altitude reconnaissance aircraft.A Brief Historyof Titanium(Metal of the Titans)The A-12 #60-6924 – the Original Blackbirdand First Titanium Aircraft – Locatedat Blackbird Airpark in Palmdale, CA.The design and material selection for the A-12 was daunting due to thesupersonic and high altitude performance requirements. The aircraftskin, for instance, would be subjected to high temperatures, which precludedmost common aircraft metals from use. The one metal that couldbring their design concept to reality was titanium, even though there wereseveral technological advancements that would need to occur first. Ultimately,a beta titanium alloy, which had a greatstrength-to-weight ratio and good resistance tohigh temperatures, was selected. Practically theentire aircraft was made from titanium. Machiningof titanium was also especially difficult, and newtooling was developed for the explicit purpose offabricating titanium parts for the A-12.Even though the program was highly secret,President Johnson acknowledged that the US hadbeen engaged in an effort to develop an advancedjet aircraft. (He did intentionally mention the nameof an earlier design, the A-11, rather than identifythe existence of the A-12.) The President also notedduring his public announcement that a “mastery ofthe metallurgy and fabrication of titanium metal”had been achieved to help make the program a success.In this case, the need for an advanced aircraftdesign pushed the technological development oftitanium metallurgy and manufacturing processes, ultimately resulting inthe A-12 – the first aircraft built out of titanium. Its famed successor, theSR-71, was also built out of titanium.The history of advancements and applications of titanium technologyis interesting, especially the era between the late 1940s and early 1960s,and much of this history has been preserved. <strong>AMMTIAC</strong> is a centerthat is the culmination of numerous predecessors, the most notable ofwhich was the first: the Titanium Metallurgical Laboratory, established in1955. Much of the history of the development titanium, therefore, hasbeen preserved in <strong>AMMTIAC</strong>’s library. If you’re interested in any legacyor current information on titanium, do not hesitate to contact me. Andif you’re ever in the Palmdale area, I highly recommend making a stop atBlackbird Airpark.Ben CraigEditorGENERAL REFERENCES AND NOTE:“Titanium Progress to Date,” Titanium Metallurgical Laboratory, March 25, 1957.D. Eylon and S.R. Seagle, “Advances in Titanium Technology – an Overview,”Science and Technology of Light Metals in the 21st Century, Journal of the JapanInstitute of Light Metals, <strong>Vol</strong>. 50, <strong>No</strong>. 8, 2000, pp. 359-370.T.P. McIninch, “The Oxcart Story – Record of a Pioneering Achievement,” CIAHistorical Review Program, Central Intelligence Agency, 1994. (Approved forRelease)* Skunk Works is a registered trademark of the Lockheed Martin Corporation.Editor-in-ChiefBenjamin D. CraigPublication DesignCynthia LongTamara R. GrossmanInformation ProcessingPatricia BissonettePerry OnderdonkInquiry ServicesRichard A. LaneProduct SalesGina NashThe <strong>AMMTIAC</strong> <strong>Quarterly</strong> is published by the <strong>Advanced</strong> <strong>Materials</strong>, Manufacturing, and Testing InformationAnalysis Center (<strong>AMMTIAC</strong>). <strong>AMMTIAC</strong> is a DoD-sponsored Information Analysis Center, administrativelymanaged by the Defense Technical Information Center (DTIC). Policy oversight is provided by the Office of theSecretary of Defense, Director of Defense Research and Engineering (DDR&E). The <strong>AMMTIAC</strong> <strong>Quarterly</strong> isdistributed to more than 18,000 materials, manufacturing, and testing professionals around the world.Inquiries about <strong>AMMTIAC</strong> capabilities, products, and services may be addressed toMicheal J. MorganDirector, <strong>AMMTIAC</strong>937.542.9908EMAIL: ammtiac@alionscience.comURL: http://ammtiac.alionscience.comWe welcome your input! To submit your related articles, photos, notices, or ideas for future issues, please contact:<strong>AMMTIAC</strong>ATTN: BENJAMIN D. CRAIG201 Mill StreetRome, New York 13440PHONE: 315.339.7019FAX: 315.339.7107EMAIL:ammtiac@alionscience.com
Stephanie O’ConnorATI Wah Chang, an Allegheny Technologies CompanyAlbany, ORINTRODUCTIONDesign engineers are faced with multiple considerations when itcomes to component design and fabrication for military applications,including ease of assembly, weight reduction, structuralintegrity, corrosion resistance, long term maintenance costs, andoverall affordability. These considerations often conflict as designengineers begin to weigh the costs and benefits of each option.In the quest to achieve the best cost/benefit scenario, oldertechnologies can get overlooked in favor of newer technologies. Aprime example of an older technology that can meet today’s needsis titanium rammed graphite castings for military applications.HISTORYTitanium rammed graphite castings have been used for commercialand military applications since the late 1950s. Originally, thecast titanium parts were desired because of their superior performancein severe service applications like seawater, but designengineers quickly discovered that other benefits could also berealized by utilizing cast parts. A primary benefit was the abilityto produce near net shapes that required less material, lessmachining, and reduced scrap. Titanium’s weight advantagecompared to steel also became an advantageous characteristic.Over the last 50 years, titanium rammed graphite castingshave been used for multiple military applications, such as firepumps, water pumps, condenser head covers, and hose-to-hosepipe connectors on surface ships, torpedo ejection pumps, largeseawater pumps, various sizes of ball, gate and butterfly valves,and other defense components. Figures 1 and 2 show examplesof four different titanium components made using the rammedgraphite casting process.THE PROCESSPatterns and MoldsTitanium rammed graphite castings are made using wood, metal orplastic patterns to produce a mold, as illustrated in Figure 3. Similarto conventional sand castings (see sidebar), rammed graphite castingsuse the standard cope and drag patterns, with and without cores.Many parts can be cast using the same patterns originally constructedfor the casting of other metals. Standard loose or match-platepatterns made of either wood or metal can be used for titaniumrammed graphite castings. Standard core boxes can also be usedunless they are designed to be used for core blowing only. Most patternsfor ferrous and nickel-based alloys will conform dimensionally.Pattern shops can accommodate modifications or new construction.Generally, pattern equipment designed for sand casting processes canalso be utilized with modifications to gating and riser systems.Titanium is very reactive in the molten state, and thereforegraphite is used as a mold medium. Graphite powder is mixedwith water, pitch syrup, and starch, which act as binders. Thismixture is pneumatically tamped and rammed around the patternto form the mold.Figure 1. Cast Titanium Pump Casing (Left) and a Cast TitaniumSeal Head (Right).http://ammtiac.alionscience.com The <strong>AMMTIAC</strong> <strong>Quarterly</strong>, <strong>Vol</strong>ume 2, Number 1 3
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