Effect Of Carbide Ceramic Particles On Microstructure And Properties Of Fe₅₀Mn₃₀Co₁₀Cr₁₀ High Entropy Alloy Matrix Composites

As a new type of multi-element alloy,high entropy alloy breaks the traditional design concept of one or two elements.The coexistence of toughness and strength also exists in high entropy alloy,but recent studies show that the phase transformation induced plasticity(TRIP)effect can be activated in the high entropy alloy by component design,and the toughness of the high entropy alloy can be optimized;in addition,high hardness ceramic particles can enhance high wear resistance of the composites.In view of this,based on the TRIP type high entropy alloy with good toughness,the high entropy alloy matrix composite with high entropy is designed by doping ceramic particles.In this paper,different types and contents of carbide ceramic particles are doped in a typical TRIP type high entropy alloy(Fe₅₀Mn₃₀Co₁₀Cr₁₀).The relationship between deformation and heat treatment on the phase composition,microstructure,tensile mechanical properties and friction and wear properties of the high entropy alloy matrix composites is studied.The grain size of Fe_49.5Mn₃₀Co₁₀Cr₁₀X_0.5(X=B₄C,SiC and ZrC)samples were refined to different degrees,and the ceramic particles could stabilize the?phase and inhibit the formation of?phase.In the deformed samples,the grains break into fiber shape,and the ceramic particles distributed in streamline along the rolling direction.The deformation provides energy for the precipitation of ceramic particles during annealing,which leads to the significant increase of the precipitation of ceramic particles in recrystallized samples.The results of tensile test show that the toughness of the recrystallized samples is the best,and the fracture mechanism is ductile fracture.The bonding strength of ceramic particles and matrix is better due to the uniform distribution of alloy elements.In the recrystallized samples doped with SiC particles,there are no holes and cracks at the interface between the ceramic particles and the matrix,and the distribution of alloying elements is uniform,which leads to better interface bonding strength(YS=272Mpa,UTS=789Mpa,FE=51%);while in the samples doped with B₄C and ZrC particles,there are holes or even cracks at the interface between the ceramic particles and the matrix,meanwhile the wettability between the ceramic particles and the matrix is poor,and the distribution of alloying elements is uneven,which leads to uneven interface bonding strength,even the mechanical properties of the composite decrease obviously(B₄C:YS=422Mpa,UTS=837Mpa,FE=22%;ZrC:YS=144Mpa,UTS=473Mpa,FE=19%).In recrystallized samples of Fe_50-YMn₃₀Co₁₀Cr₁₀(SiC)_Y(Y=0,0.1,0.5,1 and 3),the grain size is refined with the increase of the content of doped SiC particles.The phase composition gradually transformed from?and?to?single phase,and the number of?phase variants decreases with the refinement of grain size.In(SiC)₃ samples,SiC particles agglomerate and form holes near the particles,which leads to the decrease of interface bonding strength.The tensile test results show that mechanical properties of(SiC)₁ sample with dispersed with fine SiC particles are the best(YS=461MPa,UTS=1157Mpa,FE=31%),and the fracture mechanism is ductile fracture.Under the condition of 2N-4HZ-Si₃N₄-30min,the wear resistance of recrystallized samples doped with different carbide ceramic particles(B₄C,SiC and ZrC)is higher than that of the matrix samples,and the wear mechanism is abrasive wear and oxidation wear.The wear resistance of recrystallized samples doped with different SiC contents(0,0.1,0.5,1 and 3)increased(Y=0?1)and then decreased(Y=3).The wear mechanism was abrasive wear and oxidation wear(Y=0?0.5);abrasive wear(Y=1);abrasive wear and severe oxidation wear(Y=3),respectively.The results show that the wear rate of Fe₄₉Mn₃₀Co₁₀Cr₁₀(SiC)₁ recrystallized samples is different(friction pair,load,frequency and time):1)Different friction pairs(2N-4HZ-30min),the wear rate of samples is Si₃N₄<Al₂O₃<GCr₁₅,and the wear mechanism is abrasive wear(Si₃N₄);abrasive wear and oxidation wear(Al₂O₃);oxidation wear and adhesion wear(GCr₁₅).2)With the increase of frequency(2N-Si₃N₄-30min),the wear decreased(2?4HZ)and then increased(4?6HZ).The wear mechanism varied from slight abrasive wear to abrasive wear and oxidation wear.3)The wear rate decreased with the increase of time(2N-4HZ-Si₃N₄).The wear mechanism was:abrasive wear(0-5min);abrasive wear and oxidation wear(5?30min);oxidation wear and slight fatigue wear(30?60min).4)The wear rate changed in the form of"N"with the increase of load under different loads(4HZ-Si₃N₄-30min).The main wear mechanisms are:wear of abrasive particles(2N);wear of abrasive particles and oxidation wear(5N?10N);wear of abrasive particles,oxidation wear and adhesion wear(10N?15N).