"Principal component analysis and thermomechanical preference of white Au alloys without Ag "

Addition of different amounts of Cu and Ag to Au alloys, as well as some new elements (Zn and Cd), gives alloys of the different colour spectrum (from red to yellow) and different technological and metallurgical characteristics. The trend today is the implementation of new alloys not containing Ag, and including new elements, such as Ga and In. Differences in two Au alloys exist: the first alloy contains Ni and Pd, and the second alloy is without them. The values of electrical conductivity and hardness are different, due to the reduction, which was shown using PCA (r=0.985 and the strong positive correlation between hardness and electrical conductivity). Performed tests confirm that those multiphase multi component gold alloys can find their application not only in jewellery making but also in the world of modern electrical engineering. The performed statistical analysis shows strong positive and negative correlations of properties of investigated Au alloys, and it provides significant savings in the design and efficiency of metallurgical processes. Keywords: alloy, PCA, metallurgical process.