Research On Solution Treatment Process And Properties Of ZL205A Alloy Castings Applied On Travelling Magnetic Field During Heat Treatment

The solidification microstructure of ZL205 A alloys castings can be densified during casting, if travelling magnetic field applied. The diffusion behavior of atoms will change in the castings in solution process, which will affect the subsequent heat treatment process. The study of the effect is relatively less currently. In this paper,the research on the ZL205 A alloys castings was performed, and the heat treatment and solution process and the heat treatment properties were studied. Whether the time of heat treatment and solution process was shortened and the heat treatment properties under the process was improved were researched.The heat treatment and solution process of ZL205 A alloys castings applied travelling magnetic field during casting was researched with qualitative and quantitative methods. First, the dissolved quantity of Al2 Cu solid solution phase in different temperature and fixed solution time was analyzed with qualitative method.And then the solution process was evaluated according to the relationships between temperature and hardness, strength of alloys. Results show that the dissolved quantity of solid solution phase increases with the increasing of solid solution treatment temperature, while the hardness and strength of alloys increase at first and then decrease slightly, and then the optimal temperature of heat treatment and solution process was obtained according to the former analysis. The similar research was performed in order to get the optimal time of heat treatment and solution process. Furthermore, the optimal heat treatment and solution process was obtained.Compared with normal ZL205 A alloys castings, the ZL205 A alloys castings applied travelling magnetic field during casting have the same solution temperature and holding time but shorter heat treatment and solution time under the same mechanical strength.The mechanical properties of ZL205 A alloys castings with the above mentioned heat treatment and solution process, are improved under the standard aging process(T5, T6, T7), and tensile strength, the yield strength and elongation of the alloys achieve the optimum value in T6 conditions. Analyses of the fracture morphology show that there are more dimples distributing in ZL205 A alloys castings applied travelling magnetic field during casting more uniformly, compared with the normal ZL205 A alloys castings, which has correspondence with mechanical properties of alloys and is good for them.