Microstructure and Properties of AlCrFeCoNiCux High-Entropy Alloys

Abstract

The peculiarities of the structure formation of alloys of the system AlCrFeCoNiCu (where x = 0, 0.5, 1, 2, and 3 moles) were studied. Microstructure of alloys and its phase composition, as the amount of copper increases, undergo significant changes. In all of the investigated concentration interval of change in the content of copper there is a different phase morphology. Confirmed that with increasing of Cu concentration the nature of crystallization of alloys and their phase composition change. Durometric studies of alloys of this system were carried out. Established that an alloy AlCrFeCoNiCu 0.5 has the highest microhardness 6.1 GPa. Heat resistance tests showed that AlCrFeCoNi and AlCrFeCoNiCu have the highest heat resistance. The connection between the scale composition after the test and the mechanism of oxidation of this alloys revealed. The results of X-ray fluorescence analysis indicate a high content of aluminum in scale. Consequently, the high heat resistance of alloys can be explained by the formation of the Al 2 O 3 protective film on the surface.

Improvement of Operating Properties of Heat-Resistant Alloys by the Structure Optimization

“…Characterizing the mechanical characteristics of the alloy HX -Alloy Type 66Ni-17Cr, according to Table 1, it is clear that this material has high values of r B 750 , d, w, which is an assessment of its operational reliability. However, under the action of high temperatures, such mechanical properties [22] as elasticity, yield strength, and strength are significantly reduced. Therefore, even at stress values that are less than the yield strength, the phenomenon of creep can occur, which is manifested in a gradual increase in plastic deformation.…”