Synthesis of Boron Containing Cu-12Al-4Ni Memory Alloy powder by Using Mechanical Alloying Method and Investigating the Changes of the Density and Porosity in Bulk Samples During production

In this research Cu-12wt%Al-4wt%Ni shape memory alloy powder with and without addition of boron as alloying element was produced by using mechanical alloying method. Bulk samples were produced from the powder by press-sinter and subsequently rolling-heat treatment processes. The density and the amount of porosity of the samples were measured, subsequently. The effect of milling time on phase changes in produced powder, size of crystallites and lattice strain was also investigated. Results showed that after 20h of milling with rotating speed of 250 rpm and ball to powder mass ratio of 20:1, peaks of pure elements disappear and solid solution with FCC structure and lattice parameter close to that of copper forms. Morphology of milled powder and microstructure of bulk samples were studied by optical microscope and scanning electro-microscope. It was observed that adding boron lead to decrease in the size of particles after milling. Results showed that the density of samples after press-sinter processes decreases. However, the final density increased after rolling-heat treatment processes. It was also shown that adding boron to the powder mixture results in more homogenous distribution of porosities after rolling-heat treatment processes.