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Abstract Al-6Cu-6Mg-5Sn-3Ga- x In (x = 0, 0.5, 1, 3, 5. mass. fraction) alloys were prepared using melting and casting technique. The microstructures and properties of the alloys were investigated by X-ray diffraction, scanning electronic microscope/EDX, electron microprobe analysis, Vickers hardness, compression properties, immersion tests and electrochemical measurements. The results show that the main phases of the alloys with the indium element consist of α -Al, Al 2 MgCu, Mg 2 Sn and Al-In eutectic phases. The Al-In phases segregates in α -Al grain boundaries. The gallium elements solid solution in the matrix alloys. When the addition of In contents is 1 mass.%, the hardness of the Al-6Cu-6Mg-5Sn-3Ga-1In alloy reaches to 142HV, and the compressive strength up to 582 MPa. The Mg 2 Sn and the Al-In eutectic phases are the source of the degradation reaction, and the driving force to continue is the concentration of Al in the eutectic phase. The relationship between the degradation corrosion rate and temperature, indium element content and other factors were also discussed in this paper. Graphical abstract Image 1 Highlights • Microstructure, mechanical properties and corrosion behavior of Al-6Mg-6Cu-5Sn-3Ga- x In alloys were firstly investigated. • The investigated alloys mainly consist of α -Al matrix, Al 2 MgCu, Mg 2 Sn and Al-In eutectic phase. • The investigated alloy has a maximum degradation rate reaches 98.51 mg/(cm2 h) at 93 °C. [ABSTRACT FROM AUTHOR]

The effect of neodymium (Nd) additions from 0 to 0.2 wt.% on microstructure, mechanical properties at room and high temperature, as well as corrosion resistance of 2A70 alloy were studied by optical microscopy (OM), scanning electron microscope (SEM), transmission electron microscopy (TEM) in this paper. The results show that appropriate addition of Nd (0.15 wt.%) refines the size and enhances the density of the aging precipitates S′ phase, which lead to the increasing of mechanical properties at room and elevated temperatures. The newly formed Al8Cu4Nd compound, dispersed along grain boundary, which hinders the movement of grain boundaries at elevated temperature and improves the high temperature performance of 2A70 alloy. Compared with traditional 2A70 alloy, the intergranular corrosion of the peak-aged alloy with 0.15 wt.% Nd has also been effectively enhanced. [ABSTRACT FROM AUTHOR]

The single-phase TiNbZrMo x (x = 0, 0.3, 0.5, 0.7, 1) high-entropy alloys (HEAs) were prepared by arc melting. The relation between molybdenum, microstructure, mechanical properties and wear resistance was investigated by X-ray diffractometer (XRD), scanning electron microscope (SEM), universal tensile tester, hardness tester, friction tester, and wear tester. The results showed that TiNbZrMo x alloys were composed of a single BCC phase. With the increase of Mo elements, the crystallite size of the as-cast alloy decreased first and then increased, both the alloy strength and hardness were increased and compressive strain plasticity was decreased. TiNbZrMo 0.5 has the best comprehensive performance with a yield strength of 1.0 GPa, compressive strength of 1.3 GPa, and hardness of 429 HV; compared with TiNbZrMo 0 , yield strength increased by 77.32%, compressive strength increased by 25.14%, and hardness increased by 70.24%; and its specific wear rate decreased by 50%, while it's compressive plasticity only decreased by 5%. • The addition of appropriate amounts of molybdenum improves the strength, hardness and wear resistance of TiNbZrMo x HEAs. • Compared to TiNbZr, TiNbZrMo 0.5 has the best overall performance. • The main wear mechanisms of TiNbZrMo x (x = 0, 0.3, 0.5, 0.7, 1) are abrasive wear and oxidative wear. [ABSTRACT FROM AUTHOR]