Study On Mechanical Properties And Corrosion Characteristics Of TiZrAlVMn Alloy

As an important structural material,TiZr-based alloy is used in petrochemical industry,military equipment,biomedicine and other fields because of its low density,high specific strength,strong fatigue resistance and excellent mechanical properties.It can effectively adapt to various special environments and ensure the safety,stability and efficiency of production and scientific research.Mn,as a stable element of β phase,can expand β phase region,and play an alloying role in titanium and titanium alloy,so as to effectively improve the comprehensive mechanical properties of the alloy.In this paper,based on Ti-30Zr-5Al-3V alloy,Mn element is added to the base alloy。The effect of Mn content and hot working process on the microstructure and mechanical properties of Ti-30Zr-5Al-3V-xMn（x=0、0.5、1、1.5、3、5）alloy is studied,and the corrosion resistance of the rolled Ti-30Zr-5Al-3V-xMn（x=0、0.5、1、1.5、3、5）alloy is also studied.Ti-30Zr-5Al-3V-xMn（x=0、0.5、1、1.5、3、5）alloy was obtained by melting in a non-consumable vacuum melting furnace.The microstructure and mechanical properties of the alloy were studied by means of XRD,OM,SEM and TEM.The results show that the alloy phase group becomesαphase and β phase,and the amount of each phase is related to the amount of Mn added.With the increase of Mn content,theαphase decreases,and the β phase increases,and the comprehensive mechanical properties of the alloy increase.Among them,Ti-30Zr-5Al-3V-1.5Mn alloy is the best,but when the Mn content is more than 1.5wt.%,TiMn precipitates are formed,which makes alloy plasticity drop sharply.In addition,the effects of different cooling speed and rolling temperature on the tensile mechanical properties of Ti-30Zr-5Al-3V-xMn（x=0.5,1,1.5）alloy were studied.The results show that the plasticity of the alloy is obviously improved by water cooling treatment at the same rolling temperature,and lower rolling temperature can enhance the tensile strength of the alloy at the same cooling rate,and the alloy with the best comprehensive properties is Ti-30Zr-5Al-3V-1.5Mn alloy which is hot-rolled and water-cooled at 900℃(σ_b=1113.46MPa,σ_0.2=750.59MPa,ε=19.63%).The corrosion resistance of rolled Ti-30Zr-5Al-3V-xMn（x=0,0.5,1,1.5,3,5）alloy in 3.5%NaCl solution was studied.The results show that all the alloys have high impedance values in 3.5%NaCl solution.And with the increase of Mn content,the corrosion current density and pitting potential of the alloy first increased and then decreased,while the corrosion potential first decreased and then increased.Besides,and the corrosion resistance of the alloy containing Mn is worse than that of the alloy without Mn.When the potential is 1.5V,pitting occurs in 1.5mn alloy.