Effect of Laser Surface Modification on the Structure and Mechanical Properties of Al–8% Ca, Al–10% La, Al–10% Ce, and Al–6% Ni Eutectic Aluminum Alloys

Abstract

Additive manufacturing, which includes a set of technologies for manufacturing complex-shaped products with the required set of properties, is currently being widely developed. Most additive technologies are associated with the manufacture of the product by melting and fusion of metal powder particles by means of laser radiation. Eutectic aluminum alloys of the Al–Ca, Al–Ce, Al–La, and Al–Ni systems, which have excellent casting properties, are supposedly promising for use in additive technologies. However, there is very little information in the literature on the effect of laser processing on such eutectic structures. In this regard, the work investigated the effect of laser radiation on the structure and mechanical properties of samples from eutectic compositions, namely, Al–8% Ca, Al–10% La, Al–10% Ce, and Al–6% Ni. To do this, the continuous laser modification of their surfaces was carried out. The level of hardening was evaluated by measuring the microhardness of the modified surface. The mechanisms of fracture of specimens under tensile testing have been established. It is shown that, in the structure of the modified surfaces of samples of four alloys, the distribution of the second component becomes more uniform compared to the structure of the base metal. In the Al–8% Ca alloy, the greatest hardening effect is observed, which, however, contributes to embrittlement under tensile stress. However, the modified Al–8% Ca alloy is of interest because of its increased hardness and therefore possibly increased wear resistance. On the contrary, laser modification of the surfaces of the Al–10% Ce, Al–10% La, and Al–6% Ni alloy samples provides a lower hardening effect, but increases their tensile strength with the formation of a ductile or mixed ductile and brittle fracture. The results obtained confirm the prospects of using alloys of the Al–Ca, Al–Ce, Al–La, and Al–Ni systems in additive manufacturing.