Lightweight Titanium Heat Exchangers

"MRi proposes to develop cost effective braze joining methods for the fabrication of lightweight titanium heat exchangers. Such heat exchangers are targeted by the Air Force for use in advanced aircraft fluids heat exchanger systems in order for the weaponssystem to meet weight and cooling requirements. Development of joining processes for fabricating such light weight heat exchangers would increase both the fuel economy and aircraft performance.The proposed Phase I effort would investigate three approaches: i) MRi's new active solder alloys including Sn-Ag-Ti (200¿C) and Zn-Ag-Al (380¿C) and new Cu-Sn-Ag-Ti active filler metals with active metals and rare earth (lanthanides) additions thatpromise to make them more compatible for joining titanium, ii) higher temperature braze fillers that include Al, Cu, CuAg, InCuAgTi, CuNiTi and Ni-based braze alloys and iii) innovative activated diffusion joining methods. MRi will join with Lytron, Inc, aleading specialty heat exchanger company for heat exchanger concepts and testing. Phase I efforts will develop and characterize joining techniques then selectively test to show the feasibility of fabricating reliable plate-fin titanium liquid cooling heatexchangers for use at temperatures from 200 - 500¿F. Titanium fabrications have a wide range of used based on either its high strength to weight ratio and its corrosion resistance. As such, the heat exchanger applications for military aircraft coul