Effect of (Cu-Ni) Concentrations Ratio on Recoverable Strain and the Shape Memory Effect of Ternary Smart (Cu-Al-Ni) Alloys

Abstract

The achieved results by this research determined the best ratio of (Cu-Ni) in the smart (Cu-Al-Ni) alloys that it achieve the best values of maximum recoverable strain and shape memory effect. These mechanical properties possess great technological and commercial importance in many smart applications such as aerospace and industrial applications. Three samples have different weight percentage S1(82.8%Cu, 13.5%Al, 3.7%Ni), S2(81.8%Cu, 13.5%Al, 4.7%Ni) and S3(82.4%Cu, 13.5%Al, 4.1%Ni) were manufactured from smart (Cu-Al-Ni) alloy using powder metallurgy method with heat treatment. The physical tests were performed using optical microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD) to make sure the presence of the austenite phase before heat treatment and the martensite after heat treatment. The results showed, the presence of these two phases in all samples under study. Mechanical tests were carried out which they included shape memory effect (SME) and maximum recoverable strain. The results showed that the S3 (82.4%Cu, 13.5%Al, 4.1%Ni) sample gave the best values of SME%, the maximum recoverable strain is 5% at full shape recovery (i.e. SME =100%), the maximum recoverable strain is 10% at partially shape recovery.