Effects of titanium and zirconium upon the formation and properties of W-Cu pseudoalloys

Contact interaction, structure, and properties of W(Mo, Cr)-Cu composites with additives

“…At the same we studied the structure and phase composition of the boundaries of the components of the composites, which were made by impregnating porous tungsten, molybdenum, or chromium compacts with copper or a melt of copper and an alloying element (the content of additives was determined with allowance for the results of experiments on spreading) by the method described in [11][12][13]. At the same we studied the structure and phase composition of the boundaries of the components of the composites, which were made by impregnating porous tungsten, molybdenum, or chromium compacts with copper or a melt of copper and an alloying element (the content of additives was determined with allowance for the results of experiments on spreading) by the method described in [11][12][13].…”

“…After an analysis of the variation of the interfacial energies during spreading and the nature of the interaction of the additives introduced along with the tungsten and molybdenum [17] it was found that the additives (with the exception of silver) are interfacially active at the interface between the melt and the high-melting substrate of the contact couple. The results of x-ray spectral microanalysis confLrmed that the boundary regions are enriched with those elements [11]. For example, the silver enrichment of the boundaries of the main components in the W-(Cu + Ag) composite [17] evidently can be attributed to processes similar in nature to chemical adsorption.…”

“…The possibility of such growth, obviously, is determined by the increase in the degree of interaction in the W-Ni-Cu system, the acceleration of mass transfer in the solid phase and in the presence of the liquid phase, and the attendant recrystaUization, coalescence, and recrystallization through the liquid phase. In the case of alloying with titanium the low-melting component of the composite contains an e~-solid solution of titanium and tungsten in copper as well as the intermetallic compound Cu4Ti, which precipitates at the phase boundary [ 11,16]. Like nickel, silver is redistributed in the copper, forming a solid solution.…”