Composition Design And Damping Capacity Of Al-Cr-Fe-Ni Multi-principal Alloys

Mechanical equipment often produces vibration and noise in the process of operation,which not only affects its operation accuracy and service life,but also worsens the working environment and endangers human health.Therefore,vibration and noise reduction has become a hot issue nowadays,and more and more attention has been paid to reducing vibration and noise by relying on the damping characteristics of materials.Traditional damping materials include Fe Cr,Mg,Mn Cu and other damping alloys,which have their own applications.However,few materials meet the requirements of high damping characteristics and strength characteristics at the same time.Based on Al_xCrFeNi（x=0.3,0.35,0.37,0.4,0.5,0.7 and 1.0）and AlCrFe₂Ni_x（x=1.0,1.5,1.7,2.0,2.1 and 2.3）multiphase damping alloys were designed by adjusting the molar ratio of Al and Ni respectively.The alloy samples were prepared by arc melting method and spray casting method,and the microstructure and phase composition of the alloy were examined by XRD,SEM,TEM and EBSD,etc.,and the mechanical properties and damping properties were tested.The main results are as follows:Based on Al_xCrFeNi alloy,the phase composition of the alloy gradually changes from BCC matrix to FCC matrix when x decreases from 1.0 to 0.3.When x≤0.35,the alloy phase group becomes the second phase of FCC matrix;when x≤0.37,the alloy phase group becomes the second phase of FCC matrix.When x≥0.5,the alloy consists of single BCC matrix and B2 phase.x=0.37 alloy consists of BCC matrix and FCC second phase distributed at BCC grain boundary,with corresponding volume fraction of 88.3%and11.7%,respectively;the damping property reaches the maximum,Q^-1is 0.07093;the alloy also has excellent mechanical properties,with yield strength,fracture strength and plastic strain of 1487 MPa,3160 MPa and 34.0%,respectively.Based on AlCrFe₂Ni_xalloy,the phase composition of the alloy gradually changes from BCC matrix to FCC matrix when x increases from 1.0 to 2.3.When x≤1.5,the alloy consists of single BCC matrix and B2 phase;when x≤1.7≤2.1,the alloy phase group becomes the second FCC phase distributed on the BCC matrix.The x=2.3 alloy consists of FCC matrix and the second phase of BCC.x=2.1 alloy is composed of BCC matrix and FCC second phase distributed on the matrix,the corresponding volume fraction is 89.2%and 10.8%,respectively;the damping property reaches the maximum,Q^-1is 0.06936;the alloy also has excellent mechanical properties,its yield strength,fracture strength and plastic strain are 1103.36 MPa,2907.07 MPa and 29.73%,respectively.