Preparation And Properties Of Cu-Al-Ni And Cu-Zn-Al Cellular Shape Memory Alloys

The Cu-based alloy ingots were produced through the process of vacuum smeltingmethod and induction melting method, Then we used the ingots prepar Cu-Zn-Al andCu-Al-Ni cellular alloys through infiltration cating. The preforms of NaAlO2weredissolved by the15%solution of hydrochloric acid and the10%solution of nitric acid.Metallographic Microscope, X-ray Diffractometer, Scanning Electron Microscopy, andDifferential Scanning Calorimeter were applied to characterize the phase compositions,microstructure and phase transition temperature. Then we did the compressionmechanical properties test to assess the superelasticity and the shape memory effect ofCu-Al-Ni cellular alloysThe alloy ingots had more uniform microstructure and constituent through themethod of induction melting than through the vacuum smelting. This was becausethere’s the induction electromagnetic stirring effect during the induction melting. Andthe processing of melting just used3-4minutes.There were a small quantity of metallic elements lost during infiltrating theCu-Al-Ni casting, and the martensite phase finish temperature is similar between theingots and cellular alloys. On the other hand, there were a large quantity of Zn lostduring the processing of infiltration.Porosity, load, temperature, superelasticity training and thermal-mechanicaltraining had an effect on the superelasticity and the shape memory effect of Cu-Al-Nicellular alloys. Higher porosity of Cu-Al-Ni cellular alloys had better superelasticityand shape memory effect. Superelasticity training just had an good effect onsuperelasticity, and had little effect on shape memory effect. On the other hand,thermal-mechanical training had a good results on both superelasticity and the shapememory effect.