Molecular Dynamics Of Phase Structure And Interface Properties Of Ni-W Alloy Mechanical Simulation

As a kind of nickel-based alloy,nickel-tungsten alloy has good wear resistance,corrosion resistance and oxidation resistance.It is widely used in aerospace,military,machinery,medical and other aspects.With the development of modern industry,people put forward higher requirements for the performance of nickel tungsten alloy.It is found that the properties of metals can be improved in two ways,one is to adjust the proportion of alloy composition,and the other is to regulate the interface structure.In this paper,the Ni-W alloy solid solution Ni_xW_y（tungsten content:0at.%,5at.%,1 at.%,15at.%,20at.%）and the Ni-W alloy compound Ni₄W are studied by molecular dynamics method.And nickel-tungsten alloys with single crystal,double crystal（with interface structure）,polycrystalline and dual phase structures were constructed.Tensile and shear simulations were carried out at 10K and 300K to discuss the effects of tungsten addition and different interface structures on their mechanical properties.The results show that:（1）At 10K,the tensile strength of Ni_xW_ysingle crystal in[100]and[111]orientation is always lower than that of Ni single crystal in[100]and[111]orientation,and the addition of tungsten element weakens the tensile strength of single crystal;at 300K,the tensile strength of Ni_xW_ysingle crystal in[110]orientation is always higher than that of Ni single crystal in[110]orientation,and the addition of tungsten element enhances the tensile strength of single crystal.At 10K and 300K,the elongation of Ni_xW_ysingle crystal is always lower than that of Ni single crystal,so the addition of tungsten element will lead to a decrease in elongation,the addition of tungsten element will lead to the decrease of plasticity of Ni_xW_ysingle crystal.（2）At 10K,when there is an interface in Ni_xW_y,the tensile strength and elongation ofΣ1（100）grain boundary of Ni_xW_ygrain boundary are always lower than those ofΣ1（100）grain boundary of Ni grain boundary.At this time,the addition of tungsten element will reduce the tensile strength and elongation of the interface.At 10K and 300K,when there is an asymmetric interface in the Ni_xW_ygrain boundary,the shear strength of the（100）/（110）interface,（100）/（111）interface and（110）/（111）interface of the solid solution Ni_xW_yincreases with the increase of tungsten content（0 at.%-20 at.%）.（3）At 10K and 300K,the tensile strength and shear strength of Ni_xW_ypolycrystalline with different grain sizes（average grain size:2.4 nm,1.9 nm,1.5 nm）increase with the increase of tungsten content（0 at.%-20 at.%）.（4）The tensile strength and shear strength of Ni₄W/Ni_xW_ydual-phase structure increase with the increase of tungsten content（0at.%-20at.%）in Ni_xW_yphase at 10K and 300K.The tensile strength and shear strength of Ni₄W/Ni_xW_ydual-phase structure at10K are always higher than those of Ni₄W/Ni_xW_ydual-phase structure at 300K.