Effects of the Variation of Alloy Composition on Microstructures of As-cast AlMoNbTaTiZr High-entropy Alloys

doi:10.3901/JME.2021.06.096

Abstract

Abstract: Al_aMo_bNb_cTa_dTiZr (a=1.5, 0.5, 0.25; b=0.5, 0.25, 0; c=0.5, 0; d=0.5, 0.75, 1) high-entropy alloys were prepared by a non-consumable vacuum arc melting. The relations of the content of alloying elements, thermodynamic parameters, microstructure evolution were studied. The results show that other Al_aMo_bNb_cTa_dTiZr alloys are composed of single-phase BCC solid solution phase except Al_1.5Mo_0.5NbTa_0.5TiZr alloy composed of BCC phase and Al-Zr rich precipitate. The as-cast Al_aMo_bNb_cTa_dTiZr high entropy alloy has a typical dendritic microstructure. The elements of Al, Zr and Ti, and the elements of Mo, Ta and Nb are segregated in the interdendritic and dendritic core regions, respectively. The distribution of elements during solidification is scarcely affected by the variation of alloy composition. However, the precipitation of Al-Zr rich precipitate is more significantly affected by Al than Zr. The inhibition of Al-Zr rich precipitate occurs and a solid solution with coarser dendrites is formed in the Al_aMo_bNb_cTa_dTiZr high-entropy alloys with the reduction of a, b, c and d. Al_1.5Mo_0.5NbTa_0.5TiZr alloy shows the highest micorhardness with the value of 650.0HV0.3 due to the precipitation of Al-Zr rich phase, and Al_0.25NbTa_0.5TiZr alloy shows the lowest micorhardness with the value of 407.6HV0.3.

Key words: AlMoNbTaTiZr refractory high-entropy alloy, as cast, phase formation criterion, microstructure

CLC Number:

TG146

YU Qiuying, HE Xiaoyong, XIE Xiaochang, FANG Shuang, LI Neng, HUANG Shuai, XIONG Huaping. Effects of the Variation of Alloy Composition on Microstructures of As-cast AlMoNbTaTiZr High-entropy Alloys[J]. Journal of Mechanical Engineering, 2021, 57(6): 96-105.

References

[1] 张勇. 先进高熵合金技术[M]. 北京:化学工业出版社,2019. ZHANG Yong. Advanced technology in high-entropy alloys[M]. Beijing:Chemical Industry Press,2019.
[2] 马明星,王志新,周家臣,等. Ti掺杂对CoCrCuFeMn高熵合金组织结构和耐磨性的影响[J]. 机械工程学报,2020,56(10):110-116. MA Mingxing,WANG Zhixin,ZHOU Jiachen,et al. Effect of Ti doping on microstructure and wear resistance of CoCrCuFeMn high-entropy alloys[J]. Journal of Mechanical Engineering,2020,56(10):110-116.
[3] 王晓鹏,孔凡涛. 高熵合金及其他高熵材料研究新进展[J]. 航空材料学报,2019,39(6):1-19. WANG Xiaopeng,KONG Fantao. Resent development in high-entropy alloys and other high-entropy materials[J]. Journal of Aeronautical Materials,2019,39(6):1-19.
[4] WANG M,MA Z L,XU Z Q,et al. Designing VxNbMoTa refractory high-entropy alloys with improved properties for high-temperature applications[J]. Scripta Materialia,2021,191:131-136.
[5] ZOU Y,OKLE P,YU H,et al. Fracture properties of a refractory high-entropy alloy:In situ micro-cantilever and atom probe tomography studie[J]. Scripta Materialia,2017,128:95-99.[6] NONG Z S,LEI Y N,ZHU J C. Wear and oxidation resistances of AlCrFeNiTi-based high entropy alloys[J]. Intermetallics,2018,101:144-151.
[7] LIU K M,KOMARASAMY M,GWALANI B,et al. Fatigue behavior of ultrafine grained triplex Al0.3CoCrFeNi high entropy alloy[J]. Scripta Materialia,2019,158:116-120.
[8] BACHANIA S K,WANGA C J,LOUB B S,et al. Microstructural characterization,mechanical property and corrosion behavior of VNbMoTaWAl refractory high entropy alloy coatings:Effect of Al content[J]. Surface and Coatings Technology,2020,403:126351.
[9] LU C,NIU L,CHEN N,et al. Enhancing radiation tolerance by controlling defect mobility and migration pathways in multicomponent single-phase alloy[J]. Nature Communications,2016(7):13564.
[10] 李青宇,张航,李涤尘,等. 激光增材制造WNbMoTa高性能高熵合金[J]. 机械工程学报,2019,55(15):10-16. LI Qingyu,ZHANG Hang,LI Dichen,et al. Manufacture of WNbMoTa high performance high-entropy alloy by laser additive manufacturing[J]. Journal of Mechanical Engineering,2019,55(15):10-16.
[11] ANTHOULA P,EMMANUEL G,ANGELA L,et al. Dry-sliding wear response of MoTaWNbV high entropy alloy[J]. Advanced Engineering Materials,2017,19:1600535.
[12] LAPLANCHE G,GADAUD P,PERRIERE L,et al. Temperature dependence of elastic moduli in a refractory HfNbTaTiZr high-entropy alloy[J]. Journal of Alloys and Compounds,2019,799:538-545.
[13] WANG W,ZHANG Z T,NIU J Z,et al. Effect of Al addition on structural evolution and mechanical properties of the AlxHfNbTiZr high-entropy alloys[J]. Materials Today Communications,2018,16:242-249.
[14] JENSEN J K,WELK B A,WILLIAMS R E A,et al. Characterization of the microstructure of the compositionally complex alloy Al₁Mo_0.5Nb₁Ta_0.5Ti₁Zr₁[J]. Scripta Materialia,2016,121:1-4.
[15] 魏耀光,郭刚,李静. 难熔高熵合金在航空发动机上的应用[J]. 航空材料学报,2019,39(5):82-93. WEI Yaoguang,GUO Gang,LI Jing. Application of refractory high entropy alloys on aero-engines[J]. Journal of Aeronautical Materials,2019,39(5):82-93.
[16] SENKOV O N,WOODWARD C,MIRACLE D B. Microstructure and properties of aluminum-containing refractory high entropy alloys[J]. JOM,2014,66(10):2030-2042.
[17] UICHIRO M. Hume-Rothery rules for structurally complex alloy phases[M]. Boca Raton:CRC Press,2016.
[18] ZHANG Y,ZHOU Y J,LIN J P,et al. Solid-solution phase formation rules for multi-component alloys[J]. Advanced Engineering Materials,2008,10:534-538.
[19] TAKEUCHI A,INOUE A. Classification of bulk metallic glasses by atomic size difference,heat of mixing and period of constituent elements and its application to characterization of the main alloying element[J]. Materials Transactions,2005,46:2817-2829.
[20] OTTO F,YANG Y,BAI H,et al. Relative effects of enthalpy and entropy on the phase stability of high-entropy alloys[J]. Acta Materialia.,2013,61:2628-2638.
[21] YANG X,ZHANG Y. Prediction of high-entropy stabilized solid-solution in multi-component alloys[J]. Materials Chemistry and Physics,2012,132:233-238.
[22] GUO S,LIU C T. Phase stability in high entropy alloys:Formation of solid-solution phase or amorphous phase[J]. Progress in Natural Science:Materials International,2011,21:433-446.
[23] SENKOV O N,SENKOVA S V,WOODWARD C. Effect of aluminum on the microstructure and properties of two refractory high-entropy alloys[J]. Acta Materialia,2014,68:214-228.
[24] SENKOV O N,ISHEIM D,SEIDMAN D N,et al. Development of a refractory high entropy superalloy[J]. Entropy,2016,18:102.
[25] JENSEN J. Characterization of a high strength,refractory high entropy alloy,AlMo_0.5NbTa_0.5TiZr[D]. Columbus:The Ohio State University,2017.
[26] 何银花,王发展. 对流扩散-多相相变体系内柱状晶/等轴晶形成过程的数值模拟[J]. 材料工程,2017,45(6):104-111. HE Yinhua,WANG Fazhan. Numerical simulation of columnar crystal/equiaxed crystal formation model in a convection diffusion-multiphase transformation system[J]. Journal of Materials Engineering,2017,45(6):104-111.