Tungsten alloy ,also named tungsten heavy alloy, generally is refractory metal, which have two-phase composites consisting of W-Ni- Fe or W-Ni- Cu or even W-Ni-Cu-Fe, some tungsten alloys are added Co、Mo、Cr, etc. They have very high melting point and have a density twice that of steel and are more than 50% heavier than lead. Tungsten content in conventional heavy alloys varies from 90 to 98 weight percent and is the reason for their high density (between 16.5 and 18.75 g/cc).