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Abstract: The solidified structure of ZK60 magnesium alloys in the presence and absence of electromagnetic stirring during the solidification process was compared, and the precipitates of ZK60 magnesium alloys were analyzed after a solution heat treatment using optical microscopy, micro-hardness analysis, X-ray diffraction and scanning electron microscopy. The results showed that the microstructure of cast alloys under a low-frequency alternating magnetic field (LFAMF) was mainly composed of a primary crystalline Mg matrix and a non-equilibrium eutectic structure (Mg+MgZn+MgZn2). In comparison with the microstructure observed in the absence of the electromagnetic field, the eutectic network structure on the grain boundary under low-frequency alternating magnetic field was finer and exhibited a more uniform grain distribution. The grains under the LFAMF were refined in comparison with those under no electromagnetic field before the solution heat treatment, and the former grain distribution was more uniform than the latter after the solution heat treatment. The more uniform grain distribution is because the solution heat treatment is conducive to the dissolution of the second phase particles. The hardness exhibited a downward trend with increasing solution heat treatment time. Under the same solution heat treatment, the hardness value of the samples prepared under the LFAMF was lower than those prepared in the absence of the electromagnetic field. In contrast, the mechanical properties of alloys prepared under the LFAMF were better than those prepared in the absence of the electromagnetic field. [Copyright &y& Elsevier]

Abstract: This work firstly presents detailed evidence of the fcc-type miscibility gap in the Cu–Ni–V system at temperatures between 1000°C and 1100°C. The phase equilibria, phase transformation behavior and microhardness of the (Cu0.5Ni0.5)100−xVx (at.%) (x=2, 4, 6, 8, 10, 12) alloys have been investigated by electron probe microanalysis, X-ray diffraction, differential scanning calorimetry and Vickers hardness tester, confirming that the fcc-type miscibility gap exists in the Cu–Ni–V system at temperatures between 1000°C and 1100°C. The obtained results will not only help to well understand the strengthening mechanisms in the Cu–Ni–V alloys at high temperatures, but also to effectively develop new high-temperature spinodal-hardened Cu–Ni–V base alloys in the future. [ABSTRACT FROM AUTHOR]