Alloys of the Mo?W System

Abstract

1. Melting of Mo−W alloys with >20% W requires more power than melting of unalloyed molybdenum or tungsten. The power required is highest for melting alloys with 80–85% W. 2. Alloys with 17–85% W have considerably finer grains as-cast than unalloyed molybdenum or tungsten; the grains are finest for the most highly alloyed alloy (Mo+56%W). 3. With increasing tungsten concentrations the density of Mo−W alloys increases, reaches a peak for the alloy with 60% W, and then declines. 4. At low (20°) and high (1800°) temperatures the strength characteristics of Mo−W alloys increase with the tungsten content; at moderate temperatures (400–1600°) the strength is highest for the alloys most highly alloyed. Alloying of molybdenum with tungsten reises the temperature range in which molybdenum exhibits hot shortness. The ductile-britle transition temperature increases most when over 85% W is added.