Preparation Of High-entropy Alloy And Research On Microstructure And Mechanical Properties

The high entropy alloy system is made up of five to thirteen principal elements atequimolar or near-equimolar compositions. The concept of high entropy alloy hasattracted extensive attention of scholars when it was proposed. Generally, high entropyalloy has good mechanical properties, friction and wear performance, corrosion resistance,high temperature oxidation resistance and other excellent performance, and it will be oneof the most potential materials in the future. But the research of high entropy is still in theprimary stage, theory system of high entropy is not perfect enough and it still inexperimental research.In this paper, we designed and prepared of AlFeCoNiCrCuVx, Cu0.5FeAlNiCrMox,CuFeAlNiCrMnM0.5(M=V,Ti,Mo) alloys and nitride FeCoNiCuVZrAl film. Theirmicrostructure and mechanical properties were investigated. The experimental results areas follows:(1) AlFeCoNiCrCuVxhigh entropy alloys: AlFeCoNiCrCuVxhigh entropy alloys arecomposed by FCC and BCC solid solution. The organization of this alloy system istypical dendritic crystal structure.With the increasing of V element, the organization ofalloy is obviously refined, the hardness and strength of alloy increase gradually andplastic reduces. AlFeCoNiCrCuV1.0alloy has the highest hardness,532HV, andmaximum strength,1707Mpa.(2) Cu0.5FeAlNiCrMoxhigh entropy alloys: Cu0.5FeAlNiCrMo0consists of singleBCC solid solution, Cu0.5FeAlNiCrMo0.5and Cu0.5FeAlNiCrMo1.0consist ofBCC+ordered BCC solid solution. The organization of the alloy system is typicaldendritic crystal structure. Due to atomic radius of Mo is large, lattice constant of twokinds of BCC increases with the addition of Mo. The Mo element can refine theorganization of alloy significantly, so the strength and the plastic of the alloy increasegradually. The Cu0.5FeAlNiCrMo1.0has the largest hardness value, is823HV.Cu0.5FeAlNiCrMo0.5alloy has the best comprehensive performance in this alloy system,its hardness is717HV, compressive strength is2153Mpa, and the strain value is7%. (3) CuAlFeNiCrMn(M)0.5high entropy alloys: CuAlFeNiCrMn alloy consists ofBCC+ordered BCC solid solution; CuAlFeNiCrMnV0.5high entropy alloy consists ofBCC+FCC solid solution; CuAlFeNiCrMnTi0.5high entropy alloy consists ofFCC+ordered BCC+BCC solid solution; CuAlFeNiCrMnMo0.5high entropy alloyconsists of single ordered BCC solid solution. The hardness and strength of alloysincrease gradually with the addition of M, but the strength of CuAlFeNiCrMnV0.5highentropy alloy is not promoted, which may be due to the bulky grain ofCuAlFeNiCrMnV0.5high entropy alloy. The CuAlFeNiCrMnMo0.5high entropy alloy hasthe best properties, its hardness is628HV, the compressive strength is1800Mpa, and thestrain value is4.7%.(4) FeCoNiCuVZrAl high entropy alloys films:All high entropy alloys films withdifferent N2concentrationare are amorphous. When N2concentration reached30%, aperfect dense and smooth amorphous film was obtained, where the hardness and Young’smodulus of the film reached the maximum values of12and166GPa, respectively.In summary, we prepared three series of high-entropy alloy systems and films, andexplored the effects of alloying elements on the micostructure and mechanical properties,which is important and meaningful for further development and appplacation ofhigh-entropy alloys.