Synthesis of Ni – Ti alloy from Elemental Powders by Direct Laser Deposition

Abstract

The paper investigates current trends in the development of advanced additive manufacturing technology — laser cladding or direct laser deposition (DLD). This technology for the manufacture of metal parts is less known than selective laser melting (SLM) due to its low accuracy, but it has great opportunities for the manufacture of large single parts from functional alloys. The paper analyzes the prospects and economic efficiency of the DLD modification, which consists of the synthesis of an alloy with the simultaneous building of a product from elemental powders. The synthesis of the alloy is carried out using the example of the Ni – Ti system. The economic assessment of the cost of the initial components shows the average cost of raw materials for this alloy at 200 $/kg at the cost of an alloyed alloy from 250 $/kg. An experiment of building a thin-walled and multilayer sample of an equiatomic alloy from a 55Ni — 45Ti mechanical powder mixture in a protective chamber is presented in the practical part of the work. It is shown that the presence of a protective chamber for this alloy significantly affects the chemical composition and distribution of elements within the track but is not a prerequisite for the shaping of the part. The grown thin-walled bushing showed an excess of titanium in its composition relative to the initial mixture. On the other hand, the multilayer sample in the form of a cylinder was very close to the original composition with an accuracy of one hundredth of Ni and Ti (in mass %). The results showed that this method is promising for alloy formation and the simultaneous building of a functional material requiring high precision in chemical composition. This research was funded through a grant by the Russian Science Foundation; Project No. 19-79-30002.