Understand the classification characteristics and advantages of tungsten steel alloys

Tungsten alloy according to its composition can be divided into W-Ni-Cu,W-Ni-Fe two series and W-Ni-Cr,W-Ni-Mo,W-Ni-Co alloy.
1,W-Ni-Cu alloy
W-Ni-Cu alloy is mainly composed of W,Ni,Cu powder by mixing and pressing.Among them,W content is generally 80% to 90%,adding Ni and Cu binder,in the liquid phase after the formation of two-phase alloy,the density close to the theoretical density.The alloy, in addition to W,Ni,the remaining content is the copper content.Copper in the alloy can improve the strength and plasticity of tungsten alloy.In terms of performance,the alloy does not have magnetic properties for special applications,and other physical properties are the same as the overall performance of tungsten alloys.
2,W-Ni-Fe alloy
W-Ni-Fe alloy is made of W,Ni,Fe powder by mixing and pressing.Which tungsten content of up to 80% to 90% and nickel,iron play the role of adhesive.After the liquid phase sintering to form two-phase alloy,density and theoretical density is similar.Nickel is an indispensable element in the liquid sintering process,the general content of 0.5% to 12%,if more than 12%,the alloy heat resistance and corrosion resistance will be reduced.Iron content is generally between 0.5% to 8%,if more than 8% of the alloy will increase the brittleness.Iron in the alloy can improve the strength and plasticity,this kind of alloy has a certain magnetic,can be used as armor-piercing missile core material,sub-bombs and other high-momentum kill debris,counterweight and other industrial fields.Compared with W-Ni-Cu alloy,the strength and plasticity of the alloy are all better.
3,W-Ni-Cr alloy
W-Ni-Cr alloy in the Cr element in the alloy as a solid solution to strengthen the addition of elements,with improved corrosion resistance and high temperature oxidation resistance,but also can improve the high temperature strength and hardness of the alloy.The general content of 0.2% to 5%.The hardness of this alloy is very high(HV = 600, and W-Ni-Fe alloy hardness HV = 310).The mechanical properties of the alloy depends on the Cr / Ni ratio,when the ratio is low when the plastic is better,higher hardness;low ratio of high hardness,low tensile strength,almost no plasticity.
4,W-Ni-Mo alloy
The Mo element in the alloy and W-Ni-Cr alloy in the role of Cr elements are basically the same,as the solid solution to strengthen the additive element,the content of 0 ~ 25%.In the liquid phase sintering can be dissolved in the bond phase,play a solid solution strengthening,refining the role of grain,effectively improve the mechanical properties of the alloy,improve high temperature strength and thermal shock resistance.The results show that with the increase of Mo content,the yield strength,ultimate tensile strength and hardness of the alloy will be improved,while the ductility and sintering density will decrease.
5,W-Ni-Co alloy
Co element in the alloy as a synergistic strengthening of the elements can improve the high temperature properties of the alloy,in particular,to strengthen the bonding phase,to avoid the formation of alloy compounds,significantly improve the alloy high temperature strength and hardness,the general content of 0.5% to 5%.The results show that when the temperature is higher than 500 degrees Celsius,the strength and plasticity of the alloy is obviously higher than that of W-Ni-Fe alloy.