Research On Microstructure And Properties Of Tungsten High-Entropy Alloy

Traditional alloy systems are based on one or two elements,the main element influences the property of the alloy,the traditional alloy design concept the greater the number of main elements,the easier to formate intermetallic compound and other complex phase,which will deteriorate the performance of the alloy and make the role of elements difficult to analyze.High entropy alloy as a new alloy,breaking traditional alloy design concept,using five or more elements with equimolar or nearly equimolar ratio mixing alloy,it improve the alloy mixing entropy,promote the formation of solid solution,sometimes even form intermetallic compounds and amorphous phase,both of these strengthen the alloy performance.In this paper,several kinds of Al,Fe,Ti,Cr,Ni,Zr,W,Mo and Nb elements were used to prepare for alloys with equimolar ratio.The FeTiNbMo W,FeCr NiMo NbW,FeTiCrNiMo NbW,AlFeCrNiMo NbW and TiZr MoNbW alloys were smelted by nonconsumable arc melting furnace.The microstructure and phase struction of the high-entropy alloys were analyzed by SEM,EDS and XRD.Furthermore the density,hardness and compression performance of the alloys were tested respectively.The results show that the FeTiCr NiMo NbW and TiZr MoNbW high entropy alloys form a simple solid solution structure,several other alloys are composed of simple solid solution and intermetallic compound,The morphology of FeTiNbMo W,Fe CrNiMo NbW,FeTiCr NiMo NbW and AlFe Cr NiMo NbW high entropy alloys are typical dendritic morphology,but the organizations of TiZr Mo NbW high-entropy alloy is seem as cotton.The measured density of the five kinds of high-entropy alloys are higher than the theoretical density.Rockwell hardness of the alloys is between 54.5 HRC and 66.8 HRC,Microhardness of the dendrites are higher than that of the dendrites.Annealing hardness of the alloy is higher than that of the casting hardness,FeTiCrNiMo NbW and AlFe CrNiMo NbW alloys suffer softening phenomenon at 1200 ?.The strength of the alloys is in the range of 563.35MPa~2426.91 MPa,the fracture form is cleavage fracture,TiZrMo NbW high entropy alloy property is best.