Properties Of Zr-Al-Ni-Cu Amorphous Alloy Powders And Corresponding Bulk Amorphous Alloys

Zr-based amorphous alloys have excellent mechanical properties,corrosion resistance,and biocompatibility,and are a promising new material.However,the small critical size and room temperature brittleness of amorphous alloys restrict their wide application.Bulk amorphous alloy composites are one of the measures to solve the above application bottlenecks.Therefore,it is of great significance to prepare bulk amorphous alloy composites with excellent properties.Five Zr-Al-Ni-Cu alloys with different compositions were selected,the master alloy was smelted in a vacuum arc furnace,and pulverized into powder,and then the alloy powder was ball-milled in a ball-milling tank filled with absolute ethanol,using spark plasma sintering technology Bulk amorphous materials were prepared;XRD was used to detect the structure of powders and bulk materials after ball milling at different times,SEM to observe the morphology of powders and bulk materials,DSC to study the crystallization behavior of powders,EDS to analyze alloy composition distribution,microhardness The meter measures the hardness of bulk amorphous materials,and the Archimedes method measures the density of bulk amorphous materials.The following results are obtained:With the increase of ball milling time,the powder particle morphology gradually tends to flatten and flocculate from irregular shape,and the powder particle size decreases with the increase of ball milling time.The time for ball milling of five different compositions of Zr-Al-Ni-Cu alloy powders into amorphous composite powders varies with the alloy composition,that is,18-32 h.The changing law of crystalline phase with ball milling time can be summarized as:Al Zr+Zr₂Cu+Zr Al₂+Ni Al+Zr Ni Al→Zr Al₂+Al Zr+Fe_1.945C_0.055→amorphous phase+Fe_1.945C_0.055phase.There is such a relationship in Zr₅₅Al₁₅Ni₁₀Cu₂₀,that is,E_p>E_x>E_g,indicating that the glass transition of the amorphous alloy powder is easier than crystallization,and the crystallization mechanism of the studied Zr-based amorphous alloy hardly depends on the heating rate and annealing temperature..For the bulk amorphous alloy composites produced by spark plasma sintering,the results show that increasing the sintering temperature and sintering pressure has a significant effect on the microstructure and properties of the Zr-based bulk amorphous alloy composites.When the ratio of Ni/Cu is higher,when Ni:Cu=1:2,that is,Zr₅₅Al₁₅Ni₁₀Cu₂₀is most sensitive to sintering temperature and sintering pressure.With the increase of sintering pressure and sintering temperature,the surface morphology of the block becomes more and more Smooth,the pores are also reduced,and its density,density,and hardness also increase.When the sintering pressure is35 MPa,the sintering temperature is increased from 600℃to 700℃,the density is increased by about 28%,the density is as high as 99.5%,and the hardness is as high as 1111.0 HV;when the sintering pressure is increased to 600 MPa,the sintering temperature is 400℃,the density is89.1%,the density is significantly improved,and the hardness is increased from 236.4 HV to564.1 HV.