The Effect of Temperature and Artifical Aging Time on the Hardness and Crystal Structure of the Shape Memory Alloy Cu0,83 Al0,14 Zn0,03

Shape memory alloys can revert to their original form when deformed and heated beyond their transformation temperature, known as the shape memory effect. This study explored the impact of temperature and artificial aging on Cu0,83Al0,14Zn0,03 alloy created via powder metallurgy. The alloy, comprising Cu, Al, and Zn powders, underwent a 3-h ball milling process, forming green density samples of 20 mm diameter and 5 mm thickness through 10 tons of pressure for 5 min. Subsequent steps included sintering at 750°C for 1 h, fast immersion in brine media, and artificial aging at 250°C and 300°C. Aging maintained a fixed 30- minute time, with holding times of 45 and 90 min at a constant 250 ℃. Results showed a consistent reduction in crystal size (0.606 nm to 0.533 nm), an increase in dislocation density (4.815–6.056 line/mm2), and a significant rise in micro-lattice strain (0.196–0.214). Temperature and aging impacted mechanical properties, reducing hardness from 63 to 47 HB, tensile strength from 223 to 166 MPa, and yielding a diminishing yield strength. These findings underscore the intricate relationship between pro- cessing parameters, microstructure changes, and the mechanical behavior of shape memory alloys.