Microstructure Regulation And Damping Properties Of Fe₃CrNiCuAl_x High Entropy Alloy

In various fields of industry,the vibration and noise caused by mechanical movement has been paid more and more attention.Therefore,reducing vibration and noise has become an important topic in many industrial fields.The development and application of high damping alloy materials is one of the effective direct measures to reduce vibration and noise.Fe-Cr alloy is widely used in industrial vibration and noise reduction materials at present,but its structure is relatively simple,with high damping and strength characteristics of Fe-Cr damping alloy is rarely reported.In this paper,based on the design concept of high entropy alloy,the comprehensive analysis of Fe3Cr2NiCuAlx(x=0,0.125,0.25,0.5,0.75,1.0)and Fe3CrNiCuAlx(x=0.125,0.25,0.5,0.65,0.75,1.0)mechanical properties and damping properties of the two high entropy alloys by adjusting the Al mole ratio.The microstructure of Fe3Cr2NiCuAlx alloy gradually changes from FCC+BCC dualphases to BCC single-phase with the increase of Al mole ratio.When 0≤x≤0.125,FCC phase is matrix,and FCC2 nanoparticles and BCC phase are dispersed.When 0.25≤x≤1.0,the BCC phase is the matrix,in which B2 nanoparticles and FCC phase are dispersed.x=0.25 alloy,its microstructure is composed of BCC(70.1%)matrix and FCC(29.9%)second phase,has the highest damping capacity Q-1 0.056 when the strain amplitude is 5.7×10-4.At this time,the alloy does not fracture and its yield strength is 1069 MPa.The phase composition of Fe3CrNiCuAlx alloy changes successively from single-phase FCC structure to FCC+BCC dual-phase structure and finally to single-phase BCC structure with the increase of Al mole ratio.When 0.125≤x≤0.5,the alloy consists of a single FCC phase.When 0.65≤x≤1.0,the BCC phase is the matrix,in which B2 phase nanoparticles and FCC phase are dispersed.x=0.65 alloy,its microstructure is composed of BCC(74.41%)matrix and FCC(25.59%)second phase,has the highest damping capacity Q-1 0.062 when the strain amplitude is 8.3×10-4.At this time,the yield strength of the alloy is 1382 MPa,Strain is 41.66%.