tungsten W-Ni-Fe

La description

The majority of current usages for WHAs (tungsten heavy alloy) are best satisfied with the W-Ni-Fe system. As its high density, it is mostly used as tungsten alloy crankshaft for racing car weight. Tungsten heavy alloy such as *3W*4.9Ni*2.1Fe and *5W*4Ni*1Fe represent common compositions, and the addition of Co to a W-Ni-Fe alloy is a common approach for slight enhancement of both strength and ductility. The presence of cobalt within the alloy provides solid-solution strengthening of the binder and slightly enhanced tungsten-matrix interfacial strength. Cobalt additions of 5% to *5% of the nominal binder weight fraction are the most common.
Tungsten alloy, also named tungsten heavy alloy, generally is refractory metal, which has 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 *0% heavier than lead. Tungsten content in conventional heavy alloys varies from *0% to *7% and is the reason for their high density (between *6.5g/cc and *8.*5 g/cc). Nickel, iron and copper serve as a binder matrix, which holds the brittle tungsten grains together and which makes tungsten alloys ductile and easy to machine.