Gold-Aluminium Intermetallic Compound Formation

During investigations of failure mechanisms and failure avoidance we have studied the kinetics and the mechanisms responsible for the growth of the Au-Al compounds. Au4Al, Au5Al2, Au2Al, AuAl, AuAl2have been observed and the growth kinetics of the Au2Al, AuAl, AuAl2follow a(time)1/2dependence. The activation energy for the growth of Au2Al is 1 eV and 1.2 eV was found for AuAl and AuAl2. The kind of compound formed depends on the samples preparation and the results indicate that the kinetics of the mixing is the main mechanism responsible for the sequence of formation of the various compounds.