Microstructure and Mechanical Properties of Precipitate Strengthened High Entropy Alloy Al10Co25Cr8Fe15Ni36Ti6 with Additions of Hafnium and Molybdenum

High entropy or compositionally complex alloys provide opportunities for optimization towards new high-temperature materials. Improvements in the equiatomic alloy Al17Co17Cr17Cu17Fe17Ni17 (at.%) led to the base alloy for this work with the chemical composition Al10Co25Cr8Fe15Ni36Ti6 (at.%). Characterization of the beneficial particle-strengthened microstructure by scanning electron microscopy (SEM) and observation of good mechanical properties at elevated temperatures arose the need of accomplishing further optimization steps. For this purpose, the refractory metals hafnium and molybdenum were added in small amounts (0.5 and 1.0 at.% respectively) because of their well-known positive effects on mechanical properties of Ni-based superalloys. By correlation of microstructural examinations using SEM with tensile tests in the temperature range of room temperature up to 900 °C, conclusions could be drawn for further optimization steps.

[1]  H. Sebastian Seung,et al.  Trainable Weka Segmentation: a machine learning tool for microscopy pixel classification , 2017, Bioinform..

[2]  E. Affeldt,et al.  Quantitative Experimental Determination of the Solid Solution Hardening Potential of Rhenium, Tungsten and Molybdenum in Single Crystal Nickel-Based Superalloys , 2015 .

[3]  Alan K. Miller,et al.  Combining Phenomenology and Physics in Describing the High Temperature Mechanical Behavior of Crystalline Solids , 1979 .

[4]  Kevin W Eliceiri,et al.  NIH Image to ImageJ: 25 years of image analysis , 2012, Nature Methods.

[5]  C. Sullivan,et al.  Some effects of hafnium additions on the mechanical properties of a columnar-grained nickel-base superalloy , 1971 .

[6]  U. Glatzel,et al.  New multiphase compositionally complex alloys driven by the high entropy alloy approach , 2019, Materials Characterization.

[7]  Anna M. Manzoni,et al.  High-Temperature Tensile Strength of Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex Alloy (High-Entropy Alloy) , 2015 .

[8]  Chuang Dong,et al.  A cuboidal B2 nanoprecipitation-enhanced body-centered-cubic alloy Al 0.7 CoCrFe 2 Ni with prominent tensile properties , 2016 .

[9]  P. Dai,et al.  Controllable fabrication of a carbide-containing FeCoCrNiMn high-entropy alloy: microstructure and mechanical properties , 2017 .

[10]  Sebastian Haas,et al.  Tensile Behavior and Evolution of the Phases in the Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex/High Entropy Alloy , 2018, Entropy.

[11]  J. Yeh,et al.  Sluggish diffusion in Co-Cr-Fe-Mn-Ni high-entropy alloys , 2013 .

[12]  F. Pyczak,et al.  THE EFFECTS OF DIFFERENT ALLOYING ELEMENTS ON THE THERMAL EXPANSION COEFFICIENTS, LATTICE CONSTANTS AND MISFIT OF NICKEL-BASED SUPERALLOYS INVESTIGATED BY X-RAY DIFFRACTION , 2004 .

[13]  Anna M. Manzoni,et al.  On the Path to Optimizing the Al-Co-Cr-Cu-Fe-Ni-Ti High Entropy Alloy Family for High Temperature Applications , 2016, Entropy.

[14]  T. Shun,et al.  Nanostructured High‐Entropy Alloys with Multiple Principal Elements: Novel Alloy Design Concepts and Outcomes , 2004 .

[15]  Kevin W. Eliceiri,et al.  ImageJ2: ImageJ for the next generation of scientific image data , 2017, BMC Bioinformatics.

[16]  B. S. Murty,et al.  Decomposition in multi-component AlCoCrCuFeNi high-entropy alloy , 2011 .

[17]  P. S. Kotval,et al.  The role of hafnium in modifying the microstructure of cast nickel-base superalloys , 1972 .

[18]  Johannes E. Schindelin,et al.  Fiji: an open-source platform for biological-image analysis , 2012, Nature Methods.

[19]  Brian Cantor,et al.  Multicomponent and High Entropy Alloys , 2014, Entropy.

[20]  Peter W Voorhees,et al.  THE EQUILIBRIUM SHAPE OF A MISFITTING PRECIPITATE , 1994 .

[21]  J. E. Doherty,et al.  On the origin of the ductility enhancement in Hf-doped Mar-M200 , 1971 .

[22]  Michael Geselowitz,et al.  Stockholm, Sweden , 2013, IEEE Ann. Hist. Comput..

[23]  Martin E. Glicksman,et al.  Principles of Solidification: An Introduction to Modern Casting and Crystal Growth Concepts , 2010 .