Preparation of Macrocrystalline Tungsten-Based Alloys by Electron-Beam Floating Zone Melting

Abstract—Macrocrystalline tungsten alloys containing 1, 3, and 5 at % alloying additives (Re, Mo, Ta, Cr, Fe, and V) have been prepared by electron-beam floating zone melting. The resultant ingots have been characterized by weighing, chemical analysis, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The tungsten alloys with the refractory metals Re, Mo, and Ta have been shown to consist of large crystalline grains >1 cm in size, with a uniform alloying additive distribution over the alloys. The bulk of the materials is essentially free of voids. In contrast, the tungsten alloys with the low-melting-point additives Cr, Fe, and V contain numerous voids ranging in size from 0.5 μm to 2 mm. The low-melting-point alloying elements are present in the form of inclusions in the tungsten matrix. The proposed method has been shown to be suitable for producing macrocrystalline tungsten alloys with refractory metals (Re, Mo, and Ta) and inapplicable for producing macrocrystalline W alloys with light components (Cr, Fe, and V).