The Effect Of Alloying On Structure And Properties Of Zr-based Bulk Amorphous Alloy

Zr-based amorphous alloy having its unique properties,such as high strength and high hardness,and high elastic limit,has been studied widely.However,its fraglility has been restricting its application in engineering at room temperature compression.Thus,this paper has researched this problem through three ways to improve the plasticity of amorphous alloy:First,adjust the composition of the alloy by changing Ni with Cu content ratio to prepare Zr-Cu-Ni-Al amorphous,to investigate the effect of Ni with Cu content ratio on thermal stability and mechanical properties of Zr-based amorphous alloy.Second,investigating the effect of alloying on amorphous and amorphous composite microstructure through change the Al content to prepare Zr-Cu-Al amorphous and composite amorphous alloys.Third,adding trace element by changing Ag content to study the effect of trace Ag element on thermal stability and mechanical properties of Zr-Cu-Ni-Al amorphous alloy.The results show as follows:（1）The thermal stability and mechanical properties of Zr₇₀Al₈Cu_22-xNi_x（x=8.5,9,9.5,10,10.5,11）alloy with different Ni with Cu content ratio have been analyzed.The results shows that: with the Ni/Cu content ratio increase,the value of supercooled liquid region ΔT_x change from 80 K to 81 K,but the ΔTx have a bigger value than other alloys when Ni/Cu content ratio arrive 0.63 and 0.76,and when Ni/Cu content ratio arrive 0.76,which has a better thermal stability because of its ΔT_x value is 89 K and.And the plastic strain exhabits a downward tend with the Ni/Cu content ratio increase,but there exists a unnormal larger value when Ni/Cu content ratio arrive0.76,which has good plastic strain and the compressive strength has a downward tend over all with wave and changeless nature.And the young modulus value arrives the maximum value 80 GPa when Ni/Cu content ratio is 0.63,but other alloys change from58 GPa to 65 GPa.In totally,the plastic strain,compressive strength and young modulus also arrive the maximum value when Ni/Cu content ratio is 0.63.（2）By preparing of(Zr_0.72Cu_0.28)_100-xAl_x（x=0,2,4,6,8,10,12,14）wedge alloys,the effect of corrosion and corrosion process on(Zr_0.72Cu_0.28)₈₈Al₁₂ alloy microstructure and the solidification structure in the same region of various Al content samples were studied.The results show that by adjusting the corrosion and corrosion process we find out a kind of corrosion inhibitor suitable for Zr-Cu-Al alloy,which ratio is HF:HNO₃:HCL:H₂O=3:3:3:50 in 4 minutes.With the increase of Al content,the solidification structure changed from columnar crystal microstructure,equiaxed crystal,followed by changing network structure.And with the increase of Al content,the alloy microstructure changed from crystal to amorphous composite tissue,in a small amount of crystal dispersion(Zr_0.72Cu_0.28)₈₈Al₁₂ amorphous alloy and microhardness reached the highest level.（3）It was analyzed that the thermal stability and mechanical properties of((Zr_0.72Cu_0.165Ni_0.115)₈₈Al₁₂)_100-xAg_x（x=0,0.01,0.02,0.05）alloy with different Ag content.The results shows that: with the Ag content increase,the value of supercooled liquid region ΔT_x and mechanical properties both exhabit a downward tend.When x=0(Zr_0.72Cu_0.165Ni_0.115)₈₈Al₁₂alloy at room temperature mechanical properties reach biggest,compressive plastic reached 13.50%,compressive strength of 1671 MPa.combined with fracture morphology analysis,the more uniform shear zone distribution is,the smaller the distance between each other,the greater the role,the greater fracture ductility and compressive strength is.