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[en] A new approach to powder processing is employed in forming titanium aluminide composites. The processing consists of internal heating of a customized powder blend by a fast electrical discharge of a homopolar genertor. The high-energy high-rate lMJ in ls pulse permits rapid heating of an electrically conducting powder mixture in a cold wall die. This short time at temperature approach offers the opportunity to control phase transformations and the degree of microstructural coarsening not readily possible with standard powder processing approaches. This paper describes the consolidation results of titanium alumnide-based powder composite materials. The focus of this study was the definition of microstructure/processing relationships for each of the composite constituents, first as monoliths and then in composite forms

[en] Advances in kinetic energy storage devices have opened up a new approach to powder processing of high temperature composites. The processing consists of internal heating of a customized powder blend by a fast electrical discharge of homopolar generator. The high-energy high rate IMJ in 1s pulse permits rapid heating of a conducting powder in a cold wall die. This short time at temperature approach offers the opportunity to control phase transformations and the degree of microstructural coarsening not readily possible using standard powder processing approaches. This paper describes the consolidation results of two high temperature composite materials, (W-Ni-Fe)B₄C and (Ti₃Al + Nb)/SiC. The focus of this study was the identification of the reaction products formed at the matrix/reinforcement interface as a function of input energy and applied stress. Input energies beyond a threshold value for each system were required to produce detectable reaction products. In the (W-Ni-Fe)/B₄C system, the reaction products formed at 4000 kj/kg input energy under 420 MPa applied stress were a series of complex carbides and borides including W₂C,FeWb,Fe₃C,Fe₆W₆C and Ni₄B₃. The intermetallic Fe₇W₆ was also observed. In the (Ti₃Al + Nb)SiC System, the reaction products observed at 3400 kj/kg and 210 MPa were TiC and TiSi₂