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The effects of different solid-solution temperature (500, 600, 700, 800, 900°C) and holding time (0.5, 1, 1.5, 2h) on properties and microstructure of Cu-Zn-Al-Ni alloy were investigated experimentally. The result shows that the hardness of the alloy presents lowest at 700°C and then increases gradually as a function of temperature. It is also revealed that hardness has no relation with the holding time. Phase transition occurs when the temperature is 900°C, as a result of which increases the hardness of the alloy.

The degassing and dedusting mechanism of La and Ce during non-vacuum melting process of Cu-Cr-Zr alloy were analyzed by thermodynamics. The gibbs free energy changes of reactions of La and Ce with some impurties such as O2, H2, S, P and Si, were calculated to discriminate the possibility of reaction during the melting process, respectively. In addition, the effect of La and Ce on microstructure and properties were studied. The results show that La and Ce can react with O2, H2, S, P and Si, which improves the effect of degassing and dedusting remarkably; the addition of La and Ce can eliminate pine-tree crystal, fine grain and clear grain bourdary.

The microstructure of Cu-37%Zn-2%Mn-1.6%Al-0.7%Fe-0.7%Si (mass fraction)alloy was studied by scan electron microscopy, X-ray and optical microscopy. The α phase ratio and micro-hardness of this alloy after aging treatment were investigated. The results show that three kinds of phases, such as α phase, β phase and hexagonal club-shape Mn5Si3 phase were observed. The needle α phase ratio increases with aging temperature under 420°C and reach peak value 25 percent after aging at 420°C×1h. The α phase ratio begin decreases when the aging temperature over 420°C. The micro-hardness varying with aging temperature is the opposite.

The hot deformation behavior of Cu-0.35Cr-0.15Zr (wt.%) alloy was investigated by hot compression tests using a Gleeble-1500D thermal simulator system. The tests were performed under the conditions of 700°С- 820°С temperature and 0.01-10s-1strain rate. The results show that the flow behavior of the studied alloy could be described by the hyperbolic sine constitutive equation, and an active energy of 597.53 kJ/mol was calculated. The processing maps were obtained and analyzed according to the dynamic materials model. The optimum processing parameters of hot deformation of this alloy in the range of this experiment can be attained by the maps. The hot deformation temperature was 800-820°C and the strain rate was 0.01-0.1s-1.The instability zones of flow behavior can also be recognized by the maps.