Joining Metals and Ceramics that Exhibit a Large Mismatch in Coefficient of Thermal Expansion

This proposal for the U.S. Army addresses the challenges of brazing dissimilar materials, initially silicon carbide to titanium alloy Ti-6A1-4V, while achieving the minimum attachment shear strength of 2x (76MPa, 11,000psi) that of epoxy glues. TechnologyInternational, Inc. (TII) recently developed novel microwave and combustion synthesis methods for brazing polycrystalline diamond and tungsten carbide for commercial abrasive applications. These brazing techniques were developed by TII, Colorado School ofMines (CSM), and NASA JPL, with financial support from the Massachusetts Institute of Technology (MIT) Institute, the U.S. Department of Energy (DOE), and the Gas Technology Institute (GTI). The joining of dissimilar material pairs for lightweight armorusage, with coefficient of thermal expansion (CTE) ratios similar to that of diamond and tungsten carbide, can be applied with confidence using similar scientific methods and brazing techniques. TII has demonstrated the ability to control residual thermalstress while achieving attachment shear strength in excess of 345 MPa (50,000 psi). TII respectfully submits a proposal for a six-month Phase I and four-month Phase I Option project as follows:Task 1 - Materials and ProcessingTask 2 - Microwave BrazingTask 3 - Visual, Ultrasonic, Impact and Shear TestingTask 4 - Reports and Presentations 1.2. Anticipated Benefits and Potential Commercial ApplicationsHigh-strength bonding of dissimilar materials, particularly with high-performance ceramics to low and high-density metals, has commercial appeal and application in many industries. Obviously, the primary purpose of this proposal is to increase protectionof U.S. Army military hardware and personnel. Broader applications are numerous, including power turbines, heat exchangers, nozzles, commercial aircraft, automobiles, mining, and earth moving equipment, metal refining, oil refining, chemical processingfacilities, petroleum drilling and production, medical devices, and abrasives. Some of these private sector applications will require higher temperature metal substrates, such as steel, molybdenum and tungsten carbide, a modest extension of the scope ofthis proposal.Once technically successful, the economics for the market place must be addressed. For military hardware, superior ballistic performance is paramount. The tactical importance of superior lightweight armor is under the national security umbrella andoutweighs industrial commercial considerations. For military purposes, field fabrication and servicing units are well within expectations. Nevertheless, the proposed development of equipment and processes to join dissimilar materials for lightweightarmor, does not entail huge capital investment or unwieldy production components. Power requirements for this technology are less than 5 KW and the system can be designed to become modular for deployment.For private-sector applications, new product cycles and scalability are consistent with the natural flow of microwave brazing process development. Interest in licensing the process and equipment for diamond- abrasive applications has already beenexpressed. The initial size of the commercial market for an advanced method for dissimilar brazing would be 50 - 100 millions of dollars. Capital investment would be substantial in meeting what is perceived as accelerating double-digit demand and wouldmost likely be accomplished employing some or all of the following: cash flow from operations, interim financing, venture capital, partnerships, and licensing arrangements. Peripheral growth in the manufacture and servicing of processing equipment wouldfollow. Furthermore, no hazardous by-products are created, exploitation of resources is low, and other environmental impacts are negligible or non-existent.Because of TII's prior work and experience in this area, the likelihood for new discovery during a Phase I project is high and success likely. After consulting with Resource Marketing International, Inc., a Houston market research company, theconservatively estimated initial market components are shown below. For new, practical, cost effective technology where demand already exists, annual revenue growth rates are typically 20 - 30%.Estimated Annual World-wide Market PotentialCommercial Aircraft & Stationary Power Turbines $15,000,000Nozzles, valves, abrasives, slurries handling $10,000,000Oilfield and mining drilling and downhole tools $ 5,000,000Tar Sand and Oil Shell Production (synthetic oils) $ 2,000,000Earth moving and ore handling $10,000,000Automobiles, brakes, wear surfaces $ 1,000,000Heat treating, heat exchangers $ 2,000,000Wear components in automated processes $ 5,000,000Military applications $50,000,000